Merge latest changes from http://www.netlib.org/fp/dtoa.c into dtoa.cc

base/third_party/dmg_fp/dtoa.cc

 /****************************************************************
  *
  * The author of this software is David M. Gay.
  *
  * Copyright (c) 1991, 2000, 2001 by Lucent Technologies.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose without fee is hereby granted, provided that this entire notice
  * is included in all copies of any software which is or includes a copy
  * or modification of this software and in all copies of the supporting
@@ skipping 85 matching lines @@
  *      something other than "long long", #define Llong to be the name,
  *      and if "unsigned Llong" does not work as an unsigned version of
  *      Llong, #define #ULLong to be the corresponding unsigned type.
  * #define KR_headers for old-style C function headers.
  * #define Bad_float_h if your system lacks a float.h or if it does not
  *      define some or all of DBL_DIG, DBL_MAX_10_EXP, DBL_MAX_EXP,
  *      FLT_RADIX, FLT_ROUNDS, and DBL_MAX.
  * #define MALLOC your_malloc, where your_malloc(n) acts like malloc(n)
  *      if memory is available and otherwise does something you deem
  *      appropriate.  If MALLOC is undefined, malloc will be invoked
- *      directly -- and assumed always to succeed.
+ *      directly -- and assumed always to succeed.  Similarly, if you
+ *      want something other than the system's free() to be called to
+ *      recycle memory acquired from MALLOC, #define FREE to be the
+ *      name of the alternate routine.  (FREE or free is only called in
+ *      pathological cases, e.g., in a dtoa call after a dtoa return in
+ *      mode 3 with thousands of digits requested.)
  * #define Omit_Private_Memory to omit logic (added Jan. 1998) for making
  *      memory allocations from a private pool of memory when possible.
  *      When used, the private pool is PRIVATE_MEM bytes long:  2304 bytes,
  *      unless #defined to be a different length.  This default length
  *      suffices to get rid of MALLOC calls except for unusual cases,
  *      such as decimal-to-binary conversion of a very long string of
  *      digits.  The longest string dtoa can return is about 751 bytes
  *      long.  For conversions by strtod of strings of 800 digits and
  *      all dtoa conversions in single-threaded executions with 8-byte
  *      pointers, PRIVATE_MEM >= 7400 appears to suffice; with 4-byte
@@ skipping 23 matching lines @@
  *      powers of 5; omitting this lock would introduce a small
  *      probability of wasting memory, but would otherwise be harmless.)
  *      You must also invoke freedtoa(s) to free the value s returned by
  *      dtoa.  You may do so whether or not MULTIPLE_THREADS is #defined.
  * #define NO_IEEE_Scale to disable new (Feb. 1997) logic in strtod that
  *      avoids underflows on inputs whose result does not underflow.
  *      If you #define NO_IEEE_Scale on a machine that uses IEEE-format
  *      floating-point numbers and flushes underflows to zero rather
  *      than implementing gradual underflow, then you must also #define
  *      Sudden_Underflow.
- * #define YES_ALIAS to permit aliasing certain double values with
- *      arrays of ULongs.  This leads to slightly better code with
- *      some compilers and was always used prior to 19990916, but it
- *      is not strictly legal and can cause trouble with aggressively
- *      optimizing compilers (e.g., gcc 2.95.1 under -O2).
  * #define USE_LOCALE to use the current locale's decimal_point value.
  * #define SET_INEXACT if IEEE arithmetic is being used and extra
  *      computation should be done to set the inexact flag when the
  *      result is inexact and avoid setting inexact when the result
  *      is exact.  In this case, dtoa.c must be compiled in
  *      an environment, perhaps provided by #include "dtoa.c" in a
  *      suitable wrapper, that defines two functions,
  *              int get_inexact(void);
  *              void clear_inexact(void);
  *      such that get_inexact() returns a nonzero value if the
  *      inexact bit is already set, and clear_inexact() sets the
  *      inexact bit to 0.  When SET_INEXACT is #defined, strtod
  *      also does extra computations to set the underflow and overflow
  *      flags when appropriate (i.e., when the result is tiny and
  *      inexact or when it is a numeric value rounded to +-infinity).
  * #define NO_ERRNO if strtod should not assign errno = ERANGE when
  *      the result overflows to +-Infinity or underflows to 0.
+ * #define NO_HEX_FP to omit recognition of hexadecimal floating-point
+ *      values by strtod.
+ * #define NO_STRTOD_BIGCOMP (on IEEE-arithmetic systems only for now)
+ *      to disable logic for "fast" testing of very long input strings
+ *      to strtod.  This testing proceeds by initially truncating the
+ *      input string, then if necessary comparing the whole string with
+ *      a decimal expansion to decide close cases. This logic is only
+ *      used for input more than STRTOD_DIGLIM digits long (default 40).
  */
 
 #define IEEE_8087
-#if defined(__GNUC__)
-// Make gcc 4.3+ warnings about parentheses non-fatal warnings.
-#pragma GCC diagnostic warning "-Wparentheses"
-#endif
+#define NO_HEX_FP
 
 #ifndef Long
 #define Long long
 #endif
 #ifndef ULong
 typedef unsigned Long ULong;
 #endif
 
 #ifdef DEBUG
 #include "stdio.h"
 #define Bug(x) {fprintf(stderr, "%s\n", x); exit(1);}
 #endif
 
 #include "stdlib.h"
 #include "string.h"
 
 #ifdef USE_LOCALE
 #include "locale.h"
 #endif
 
+#ifdef Honor_FLT_ROUNDS
+#ifndef Trust_FLT_ROUNDS
+#include <fenv.h>
+#endif
+#endif
+
 #ifdef MALLOC
 #ifdef KR_headers
 extern char *MALLOC();
 #else
 extern void *MALLOC(size_t);
 #endif
 #else
 #define MALLOC malloc
 #endif
 
@@ skipping 14 matching lines @@
 #define IEEE_Arith
 #endif
 
 #ifdef IEEE_Arith
 #ifndef NO_INFNAN_CHECK
 #undef INFNAN_CHECK
 #define INFNAN_CHECK
 #endif
 #else
 #undef INFNAN_CHECK
+#define NO_STRTOD_BIGCOMP
 #endif
 
 #include "errno.h"
 
 #ifdef Bad_float_h
 
 #ifdef IEEE_Arith
 #define DBL_DIG 15
 #define DBL_MAX_10_EXP 308
 #define DBL_MAX_EXP 1024
@@ skipping 37 matching lines @@
 #define CONST const
 #endif
 #endif
 
 #if defined(IEEE_8087) + defined(IEEE_MC68k) + defined(VAX) + defined(IBM) != 1
 Exactly one of IEEE_8087, IEEE_MC68k, VAX, or IBM should be defined.
 #endif
 
 typedef union { double d; ULong L[2]; } U;
 
-#ifdef YES_ALIAS
-#define dval(x) x
 #ifdef IEEE_8087
-#define word0(x) ((ULong *)&x)[1]
-#define word1(x) ((ULong *)&x)[0]
+#define word0(x) (x)->L[1]
+#define word1(x) (x)->L[0]
 #else
-#define word0(x) ((ULong *)&x)[0]
-#define word1(x) ((ULong *)&x)[1]
+#define word0(x) (x)->L[0]
+#define word1(x) (x)->L[1]
 #endif
+#define dval(x) (x)->d
+
+#ifndef STRTOD_DIGLIM
+#define STRTOD_DIGLIM 40
+#endif
+
+#ifdef DIGLIM_DEBUG
+extern int strtod_diglim;
 #else
-#ifdef IEEE_8087
-#define word0(x) ((U*)&x)->L[1]
-#define word1(x) ((U*)&x)->L[0]
-#else
-#define word0(x) ((U*)&x)->L[0]
-#define word1(x) ((U*)&x)->L[1]
-#endif
-#define dval(x) ((U*)&x)->d
+#define strtod_diglim STRTOD_DIGLIM
 #endif
 
 /* The following definition of Storeinc is appropriate for MIPS processors.
  * An alternative that might be better on some machines is
  * #define Storeinc(a,b,c) (*a++ = b << 16 | c & 0xffff)
  */
 #if defined(IEEE_8087) + defined(VAX)
 #define Storeinc(a,b,c) (((unsigned short *)a)[1] = (unsigned short)b, \
 ((unsigned short *)a)[0] = (unsigned short)c, a++)
 #else
 #define Storeinc(a,b,c) (((unsigned short *)a)[0] = (unsigned short)b, \
 ((unsigned short *)a)[1] = (unsigned short)c, a++)
 #endif
 
 /* #define P DBL_MANT_DIG */
 /* Ten_pmax = floor(P*log(2)/log(5)) */
 /* Bletch = (highest power of 2 < DBL_MAX_10_EXP) / 16 */
 /* Quick_max = floor((P-1)*log(FLT_RADIX)/log(10) - 1) */
 /* Int_max = floor(P*log(FLT_RADIX)/log(10) - 1) */
 
 #ifdef IEEE_Arith
 #define Exp_shift  20
 #define Exp_shift1 20
 #define Exp_msk1    0x100000
 #define Exp_msk11   0x100000
 #define Exp_mask  0x7ff00000
 #define P 53
+#define Nbits 53
 #define Bias 1023
+#define Emax 1023
 #define Emin (-1022)
 #define Exp_1  0x3ff00000
 #define Exp_11 0x3ff00000
 #define Ebits 11
 #define Frac_mask  0xfffff
 #define Frac_mask1 0xfffff
 #define Ten_pmax 22
 #define Bletch 0x10
 #define Bndry_mask  0xfffff
 #define Bndry_mask1 0xfffff
@@ skipping 34 matching lines @@
 #define Sudden_Underflow
 #ifdef IBM
 #undef Flt_Rounds
 #define Flt_Rounds 0
 #define Exp_shift  24
 #define Exp_shift1 24
 #define Exp_msk1   0x1000000
 #define Exp_msk11  0x1000000
 #define Exp_mask  0x7f000000
 #define P 14
+#define Nbits 56
 #define Bias 65
+#define Emax 248
+#define Emin (-260)
 #define Exp_1  0x41000000
 #define Exp_11 0x41000000
 #define Ebits 8 /* exponent has 7 bits, but 8 is the right value in b2d */
 #define Frac_mask  0xffffff
 #define Frac_mask1 0xffffff
 #define Bletch 4
 #define Ten_pmax 22
 #define Bndry_mask  0xefffff
 #define Bndry_mask1 0xffffff
 #define LSB 1
 #define Sign_bit 0x80000000
 #define Log2P 4
 #define Tiny0 0x100000
 #define Tiny1 0
 #define Quick_max 14
 #define Int_max 15
 #else /* VAX */
 #undef Flt_Rounds
 #define Flt_Rounds 1
 #define Exp_shift  23
 #define Exp_shift1 7
 #define Exp_msk1    0x80
 #define Exp_msk11   0x800000
 #define Exp_mask  0x7f80
 #define P 56
+#define Nbits 56
 #define Bias 129
+#define Emax 126
+#define Emin (-129)
 #define Exp_1  0x40800000
 #define Exp_11 0x4080
 #define Ebits 8
 #define Frac_mask  0x7fffff
 #define Frac_mask1 0xffff007f
 #define Ten_pmax 24
 #define Bletch 2
 #define Bndry_mask  0xffff007f
 #define Bndry_mask1 0xffff007f
 #define LSB 0x10000
@@ skipping 23 matching lines @@
 #define rounded_quotient(a,b) a /= b
 #endif
 
 #define Big0 (Frac_mask1 | Exp_msk1*(DBL_MAX_EXP+Bias-1))
 #define Big1 0xffffffff
 
 #ifndef Pack_32
 #define Pack_32
 #endif
 
+typedef struct BCinfo BCinfo;
+ struct
+BCinfo { int dp0, dp1, dplen, dsign, e0, inexact, nd, nd0, rounding, scale, uflchk; };
+
 #ifdef KR_headers
 #define FFFFFFFF ((((unsigned long)0xffff)<<16)|(unsigned long)0xffff)
 #else
 #define FFFFFFFF 0xffffffffUL
 #endif
 
 #ifdef NO_LONG_LONG
 #undef ULLong
 #ifdef Just_16
 #undef Pack_32
@@ skipping 10 matching lines @@
 #ifndef ULLong
 #define ULLong unsigned Llong
 #endif
 #endif /* NO_LONG_LONG */
 
 #ifndef MULTIPLE_THREADS
 #define ACQUIRE_DTOA_LOCK(n)    /*nothing*/
 #define FREE_DTOA_LOCK(n)       /*nothing*/
 #endif
 
-#define Kmax 15
+#define Kmax 7
 
 double strtod(const char *s00, char **se);
 char *dtoa(double d, int mode, int ndigits,
                         int *decpt, int *sign, char **rve);
 
  struct
 Bigint {
         struct Bigint *next;
         int k, maxwds, sign, wds;
         ULong x[1];
@@ skipping 11 matching lines @@
         (int k)
 #endif
 {
         int x;
         Bigint *rv;
 #ifndef Omit_Private_Memory
         unsigned int len;
 #endif
 
         ACQUIRE_DTOA_LOCK(0);
-        if ((rv = freelist[k])) {
+        /* The k > Kmax case does not need ACQUIRE_DTOA_LOCK(0), */
+        /* but this case seems very unlikely. */
+        if (k <= Kmax && (rv = freelist[k]))
                 freelist[k] = rv->next;
-                }
         else {
                 x = 1 << k;
 #ifdef Omit_Private_Memory
                 rv = (Bigint *)MALLOC(sizeof(Bigint) + (x-1)*sizeof(ULong));
 #else
                 len = (sizeof(Bigint) + (x-1)*sizeof(ULong) + sizeof(double) - 1)
                         /sizeof(double);
-                if (pmem_next - private_mem + len <= PRIVATE_mem) {
+                if (k <= Kmax && pmem_next - private_mem + len <= PRIVATE_mem) {
                         rv = (Bigint*)pmem_next;
                         pmem_next += len;
                         }
                 else
                         rv = (Bigint*)MALLOC(len*sizeof(double));
 #endif
                 rv->k = k;
                 rv->maxwds = x;
                 }
         FREE_DTOA_LOCK(0);
         rv->sign = rv->wds = 0;
         return rv;
         }
 
  static void
 Bfree
 #ifdef KR_headers
         (v) Bigint *v;
 #else
         (Bigint *v)
 #endif
 {
         if (v) {
-                ACQUIRE_DTOA_LOCK(0);
-                v->next = freelist[v->k];
-                freelist[v->k] = v;
-                FREE_DTOA_LOCK(0);
+                if (v->k > Kmax)
+#ifdef FREE
+                        FREE((void*)v);
+#else
+                        free((void*)v);
+#endif
+                else {
+                        ACQUIRE_DTOA_LOCK(0);
+                        v->next = freelist[v->k];
+                        freelist[v->k] = v;
+                        FREE_DTOA_LOCK(0);
+                        }
                 }
         }
 
 #define Bcopy(x,y) memcpy((char *)&x->sign, (char *)&y->sign, \
 y->wds*sizeof(Long) + 2*sizeof(int))
 
  static Bigint *
 multadd
 #ifdef KR_headers
         (b, m, a) Bigint *b; int m, a;
@@ skipping 46 matching lines @@
                         }
                 b->x[wds++] = carry;
                 b->wds = wds;
                 }
         return b;
         }
 
  static Bigint *
 s2b
 #ifdef KR_headers
-        (s, nd0, nd, y9) CONST char *s; int nd0, nd; ULong y9;
+        (s, nd0, nd, y9, dplen) CONST char *s; int nd0, nd, dplen; ULong y9;
 #else
-        (CONST char *s, int nd0, int nd, ULong y9)
+        (CONST char *s, int nd0, int nd, ULong y9, int dplen)
 #endif
 {
         Bigint *b;
         int i, k;
         Long x, y;
 
         x = (nd + 8) / 9;
         for(k = 0, y = 1; x > y; y <<= 1, k++) ;
 #ifdef Pack_32
         b = Balloc(k);
         b->x[0] = y9;
         b->wds = 1;
 #else
         b = Balloc(k+1);
         b->x[0] = y9 & 0xffff;
         b->wds = (b->x[1] = y9 >> 16) ? 2 : 1;
 #endif
 
         i = 9;
         if (9 < nd0) {
                 s += 9;
                 do b = multadd(b, 10, *s++ - '0');
                         while(++i < nd0);
-                s++;
+                s += dplen;
                 }
         else
-                s += 10;
+                s += dplen + 9;
         for(; i < nd; i++)
                 b = multadd(b, 10, *s++ - '0');
         return b;
         }
 
  static int
 hi0bits
 #ifdef KR_headers
-        (x) register ULong x;
+        (x) ULong x;
 #else
-        (register ULong x)
+        (ULong x)
 #endif
 {
-        register int k = 0;
+        int k = 0;
 
         if (!(x & 0xffff0000)) {
                 k = 16;
                 x <<= 16;
                 }
         if (!(x & 0xff000000)) {
                 k += 8;
                 x <<= 8;
                 }
         if (!(x & 0xf0000000)) {
@@ skipping 13 matching lines @@
         }
 
  static int
 lo0bits
 #ifdef KR_headers
         (y) ULong *y;
 #else
         (ULong *y)
 #endif
 {
-        register int k;
-        register ULong x = *y;
+        int k;
+        ULong x = *y;
 
         if (x & 7) {
                 if (x & 1)
                         return 0;
                 if (x & 2) {
                         *y = x >> 1;
                         return 1;
                         }
                 *y = x >> 2;
                 return 2;
@@ skipping 394 matching lines @@
 #endif
         while(!*--xc)
                 wa--;
         c->wds = wa;
         return c;
         }
 
  static double
 ulp
 #ifdef KR_headers
-        (x) double x;
+        (x) U *x;
 #else
-        (double x)
+        (U *x)
 #endif
 {
-        register Long L;
-        double a;
+        Long L;
+        U u;
 
         L = (word0(x) & Exp_mask) - (P-1)*Exp_msk1;
 #ifndef Avoid_Underflow
 #ifndef Sudden_Underflow
         if (L > 0) {
 #endif
 #endif
 #ifdef IBM
                 L |= Exp_msk1 >> 4;
 #endif
-                word0(a) = L;
-                word1(a) = 0;
+                word0(&u) = L;
+                word1(&u) = 0;
 #ifndef Avoid_Underflow
 #ifndef Sudden_Underflow
                 }
         else {
                 L = -L >> Exp_shift;
                 if (L < Exp_shift) {
-                        word0(a) = 0x80000 >> L;
-                        word1(a) = 0;
+                        word0(&u) = 0x80000 >> L;
+                        word1(&u) = 0;
                         }
                 else {
-                        word0(a) = 0;
+                        word0(&u) = 0;
                         L -= Exp_shift;
-                        word1(a) = L >= 31 ? 1 : 1 << 31 - L;
+                        word1(&u) = L >= 31 ? 1 : 1 << 31 - L;
                         }
                 }
 #endif
 #endif
-        return dval(a);
+        return dval(&u);
         }
 
  static double
 b2d
 #ifdef KR_headers
         (a, e) Bigint *a; int *e;
 #else
         (Bigint *a, int *e)
 #endif
 {
         ULong *xa, *xa0, w, y, z;
         int k;
-        double d;
+        U d;
 #ifdef VAX
         ULong d0, d1;
 #else
-#define d0 word0(d)
-#define d1 word1(d)
+#define d0 word0(&d)
+#define d1 word1(&d)
 #endif
 
         xa0 = a->x;
         xa = xa0 + a->wds;
         y = *--xa;
 #ifdef DEBUG
         if (!y) Bug("zero y in b2d");
 #endif
         k = hi0bits(y);
         *e = 32 - k;
 #ifdef Pack_32
         if (k < Ebits) {
-                d0 = Exp_1 | y >> Ebits - k;
+                d0 = Exp_1 | y >> (Ebits - k);
                 w = xa > xa0 ? *--xa : 0;
-                d1 = y << (32-Ebits) + k | w >> Ebits - k;
+                d1 = y << ((32-Ebits) + k) | w >> (Ebits - k);
                 goto ret_d;
                 }
         z = xa > xa0 ? *--xa : 0;
         if (k -= Ebits) {
-                d0 = Exp_1 | y << k | z >> 32 - k;
+                d0 = Exp_1 | y << k | z >> (32 - k);
                 y = xa > xa0 ? *--xa : 0;
-                d1 = z << k | y >> 32 - k;
+                d1 = z << k | y >> (32 - k);
                 }
         else {
                 d0 = Exp_1 | y;
                 d1 = z;
                 }
 #else
         if (k < Ebits + 16) {
                 z = xa > xa0 ? *--xa : 0;
                 d0 = Exp_1 | y << k - Ebits | z >> Ebits + 16 - k;
                 w = xa > xa0 ? *--xa : 0;
                 y = xa > xa0 ? *--xa : 0;
                 d1 = z << k + 16 - Ebits | w << k - Ebits | y >> 16 + Ebits - k;
                 goto ret_d;
                 }
         z = xa > xa0 ? *--xa : 0;
         w = xa > xa0 ? *--xa : 0;
         k -= Ebits + 16;
         d0 = Exp_1 | y << k + 16 | z << k | w >> 16 - k;
         y = xa > xa0 ? *--xa : 0;
         d1 = w << k + 16 | y << k;
 #endif
  ret_d:
 #ifdef VAX
-        word0(d) = d0 >> 16 | d0 << 16;
-        word1(d) = d1 >> 16 | d1 << 16;
+        word0(&d) = d0 >> 16 | d0 << 16;
+        word1(&d) = d1 >> 16 | d1 << 16;
 #else
 #undef d0
 #undef d1
 #endif
-        return dval(d);
+        return dval(&d);
         }
 
  static Bigint *
 d2b
 #ifdef KR_headers
-        (d, e, bits) double d; int *e, *bits;
+        (d, e, bits) U *d; int *e, *bits;
 #else
-        (double d, int *e, int *bits)
+        (U *d, int *e, int *bits)
 #endif
 {
         Bigint *b;
         int de, k;
         ULong *x, y, z;
 #ifndef Sudden_Underflow
         int i;
 #endif
 #ifdef VAX
         ULong d0, d1;
@@ skipping 18 matching lines @@
 #ifndef IBM
         z |= Exp_msk11;
 #endif
 #else
         if ((de = (int)(d0 >> Exp_shift)))
                 z |= Exp_msk1;
 #endif
 #ifdef Pack_32
         if ((y = d1)) {
                 if ((k = lo0bits(&y))) {
-                        x[0] = y | z << 32 - k;
+                        x[0] = y | z << (32 - k);
                         z >>= k;
                         }
                 else
                         x[0] = y;
 #ifndef Sudden_Underflow
                 i =
 #endif
                     b->wds = (x[1] = z) ? 2 : 1;
                 }
         else {
-#ifdef DEBUG
-                if (!z)
-                        Bug("Zero passed to d2b");
-#endif
                 k = lo0bits(&z);
                 x[0] = z;
 #ifndef Sudden_Underflow
                 i =
 #endif
                     b->wds = 1;
                 k += 32;
                 }
 #else
         if (y = d1) {
@@ skipping 67 matching lines @@
 #undef d1
 
  static double
 ratio
 #ifdef KR_headers
         (a, b) Bigint *a, *b;
 #else
         (Bigint *a, Bigint *b)
 #endif
 {
-        double da, db;
+        U da, db;
         int k, ka, kb;
 
-        dval(da) = b2d(a, &ka);
-        dval(db) = b2d(b, &kb);
+        dval(&da) = b2d(a, &ka);
+        dval(&db) = b2d(b, &kb);
 #ifdef Pack_32
         k = ka - kb + 32*(a->wds - b->wds);
 #else
         k = ka - kb + 16*(a->wds - b->wds);
 #endif
 #ifdef IBM
         if (k > 0) {
-                word0(da) += (k >> 2)*Exp_msk1;
+                word0(&da) += (k >> 2)*Exp_msk1;
                 if (k &= 3)
-                        dval(da) *= 1 << k;
+                        dval(&da) *= 1 << k;
                 }
         else {
                 k = -k;
-                word0(db) += (k >> 2)*Exp_msk1;
+                word0(&db) += (k >> 2)*Exp_msk1;
                 if (k &= 3)
-                        dval(db) *= 1 << k;
+                        dval(&db) *= 1 << k;
                 }
 #else
         if (k > 0)
-                word0(da) += k*Exp_msk1;
+                word0(&da) += k*Exp_msk1;
         else {
                 k = -k;
-                word0(db) += k*Exp_msk1;
+                word0(&db) += k*Exp_msk1;
                 }
 #endif
-        return dval(da) / dval(db);
+        return dval(&da) / dval(&db);
         }
 
  static CONST double
 tens[] = {
                 1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9,
                 1e10, 1e11, 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19,
                 1e20, 1e21, 1e22
 #ifdef VAX
                 , 1e23, 1e24
 #endif
@@ skipping 19 matching lines @@
 bigtens[] = { 1e16, 1e32, 1e64 };
 static CONST double tinytens[] = { 1e-16, 1e-32, 1e-64 };
 #define n_bigtens 3
 #else
 bigtens[] = { 1e16, 1e32 };
 static CONST double tinytens[] = { 1e-16, 1e-32 };
 #define n_bigtens 2
 #endif
 #endif
 
+#undef Need_Hexdig
+#ifdef INFNAN_CHECK
+#ifndef No_Hex_NaN
+#define Need_Hexdig
+#endif
+#endif
+
+#ifndef Need_Hexdig
+#ifndef NO_HEX_FP
+#define Need_Hexdig
+#endif
+#endif
+
+#ifdef Need_Hexdig /*{*/
+static unsigned char hexdig[256];
+
+ static void
+#ifdef KR_headers
+htinit(h, s, inc) unsigned char *h; unsigned char *s; int inc;
+#else
+htinit(unsigned char *h, unsigned char *s, int inc)
+#endif
+{
+        int i, j;
+        for(i = 0; (j = s[i]) !=0; i++)
+                h[j] = i + inc;
+        }
+
+ static void
+#ifdef KR_headers
+hexdig_init()
+#else
+hexdig_init(void)
+#endif
+{
+#define USC (unsigned char *)
+        htinit(hexdig, USC "0123456789", 0x10);
+        htinit(hexdig, USC "abcdef", 0x10 + 10);
+        htinit(hexdig, USC "ABCDEF", 0x10 + 10);
+        }
+#endif /* } Need_Hexdig */
+
 #ifdef INFNAN_CHECK
 
 #ifndef NAN_WORD0
 #define NAN_WORD0 0x7ff80000
 #endif
 
 #ifndef NAN_WORD1
 #define NAN_WORD1 0
 #endif
 
@@ skipping 15 matching lines @@
                         return 0;
                 }
         *sp = s + 1;
         return 1;
         }
 
 #ifndef No_Hex_NaN
  static void
 hexnan
 #ifdef KR_headers
-        (rvp, sp) double *rvp; CONST char **sp;
+        (rvp, sp) U *rvp; CONST char **sp;
 #else
-        (double *rvp, CONST char **sp)
+        (U *rvp, CONST char **sp)
 #endif
 {
         ULong c, x[2];
         CONST char *s;
-        int havedig, udx0, xshift;
+        int c1, havedig, udx0, xshift;
 
+        if (!hexdig['0'])
+                hexdig_init();
         x[0] = x[1] = 0;
         havedig = xshift = 0;
         udx0 = 1;
         s = *sp;
         /* allow optional initial 0x or 0X */
         while((c = *(CONST unsigned char*)(s+1)) && c <= ' ')
                 ++s;
         if (s[1] == '0' && (s[2] == 'x' || s[2] == 'X'))
                 s += 2;
         while((c = *(CONST unsigned char*)++s)) {
-                if (c >= '0' && c <= '9')
-                        c -= '0';
-                else if (c >= 'a' && c <= 'f')
-                        c += 10 - 'a';
-                else if (c >= 'A' && c <= 'F')
-                        c += 10 - 'A';
+                if ((c1 = hexdig[c]))
+                        c  = c1 & 0xf;
                 else if (c <= ' ') {
                         if (udx0 && havedig) {
                                 udx0 = 0;
                                 xshift = 1;
                                 }
                         continue;
                         }
 #ifdef GDTOA_NON_PEDANTIC_NANCHECK
                 else if (/*(*/ c == ')' && havedig) {
                         *sp = s + 1;
@@ skipping 16 matching lines @@
                 if (xshift) {
                         xshift = 0;
                         x[0] = x[1];
                         x[1] = 0;
                         }
                 if (udx0)
                         x[0] = (x[0] << 4) | (x[1] >> 28);
                 x[1] = (x[1] << 4) | c;
                 }
         if ((x[0] &= 0xfffff) || x[1]) {
-                word0(*rvp) = Exp_mask | x[0];
-                word1(*rvp) = x[1];
+                word0(rvp) = Exp_mask | x[0];
+                word1(rvp) = x[1];
                 }
         }
 #endif /*No_Hex_NaN*/
 #endif /* INFNAN_CHECK */
 
+#ifdef Pack_32
+#define ULbits 32
+#define kshift 5
+#define kmask 31
+#else
+#define ULbits 16
+#define kshift 4
+#define kmask 15
+#endif
+#ifndef NO_HEX_FP /*{*/
+
+ static void
+#ifdef KR_headers
+rshift(b, k) Bigint *b; int k;
+#else
+rshift(Bigint *b, int k)
+#endif
+{
+        ULong *x, *x1, *xe, y;
+        int n;
+
+        x = x1 = b->x;
+        n = k >> kshift;
+        if (n < b->wds) {
+                xe = x + b->wds;
+                x += n;
+                if (k &= kmask) {
+                        n = 32 - k;
+                        y = *x++ >> k;
+                        while(x < xe) {
+                                *x1++ = (y | (*x << n)) & 0xffffffff;
+                                y = *x++ >> k;
+                                }
+                        if ((*x1 = y) !=0)
+                                x1++;
+                        }
+                else
+                        while(x < xe)
+                                *x1++ = *x++;
+                }
+        if ((b->wds = x1 - b->x) == 0)
+                b->x[0] = 0;
+        }
+
+ static ULong
+#ifdef KR_headers
+any_on(b, k) Bigint *b; int k;
+#else
+any_on(Bigint *b, int k)
+#endif
+{
+        int n, nwds;
+        ULong *x, *x0, x1, x2;
+
+        x = b->x;
+        nwds = b->wds;
+        n = k >> kshift;
+        if (n > nwds)
+                n = nwds;
+        else if (n < nwds && (k &= kmask)) {
+                x1 = x2 = x[n];
+                x1 >>= k;
+                x1 <<= k;
+                if (x1 != x2)
+                        return 1;
+                }
+        x0 = x;
+        x += n;
+        while(x > x0)
+                if (*--x)
+                        return 1;
+        return 0;
+        }
+
+enum {  /* rounding values: same as FLT_ROUNDS */
+        Round_zero = 0,
+        Round_near = 1,
+        Round_up = 2,
+        Round_down = 3
+        };
+
+ static Bigint *
+#ifdef KR_headers
+increment(b) Bigint *b;
+#else
+increment(Bigint *b)
+#endif
+{
+        ULong *x, *xe;
+        Bigint *b1;
+
+        x = b->x;
+        xe = x + b->wds;
+        do {
+                if (*x < (ULong)0xffffffffL) {
+                        ++*x;
+                        return b;
+                        }
+                *x++ = 0;
+                } while(x < xe);
+        {
+                if (b->wds >= b->maxwds) {
+                        b1 = Balloc(b->k+1);
+                        Bcopy(b1,b);
+                        Bfree(b);
+                        b = b1;
+                        }
+                b->x[b->wds++] = 1;
+                }
+        return b;
+        }
+
+ void
+#ifdef KR_headers
+gethex(sp, rvp, rounding, sign)
+        CONST char **sp; U *rvp; int rounding, sign;
+#else
+gethex( CONST char **sp, U *rvp, int rounding, int sign)
+#endif
+{
+        Bigint *b;
+        CONST unsigned char *decpt, *s0, *s, *s1;
+        Long e, e1;
+        ULong L, lostbits, *x;
+        int big, denorm, esign, havedig, k, n, nbits, up, zret;
+#ifdef IBM
+        int j;
+#endif
+        enum {
+#ifdef IEEE_Arith /*{{*/
+                emax = 0x7fe - Bias - P + 1,
+                emin = Emin - P + 1
+#else /*}{*/
+                emin = Emin - P,
+#ifdef VAX
+                emax = 0x7ff - Bias - P + 1
+#endif
+#ifdef IBM
+                emax = 0x7f - Bias - P
+#endif
+#endif /*}}*/
+                };
+#ifdef USE_LOCALE
+        int i;
+#ifdef NO_LOCALE_CACHE
+        const unsigned char *decimalpoint = (unsigned char*)
+                localeconv()->decimal_point;
+#else
+        const unsigned char *decimalpoint;
+        static unsigned char *decimalpoint_cache;
+        if (!(s0 = decimalpoint_cache)) {
+                s0 = (unsigned char*)localeconv()->decimal_point;
+                if ((decimalpoint_cache = (unsigned char*)
+                                MALLOC(strlen((CONST char*)s0) + 1))) {
+                        strcpy((char*)decimalpoint_cache, (CONST char*)s0);
+                        s0 = decimalpoint_cache;
+                        }
+                }
+        decimalpoint = s0;
+#endif
+#endif
+
+        if (!hexdig['0'])
+                hexdig_init();
+        havedig = 0;
+        s0 = *(CONST unsigned char **)sp + 2;
+        while(s0[havedig] == '0')
+                havedig++;
+        s0 += havedig;
+        s = s0;
+        decpt = 0;
+        zret = 0;
+        e = 0;
+        if (hexdig[*s])
+                havedig++;
+        else {
+                zret = 1;
+#ifdef USE_LOCALE
+                for(i = 0; decimalpoint[i]; ++i) {
+                        if (s[i] != decimalpoint[i])
+                                goto pcheck;
+                        }
+                decpt = s += i;
+#else
+                if (*s != '.')
+                        goto pcheck;
+                decpt = ++s;
+#endif
+                if (!hexdig[*s])
+                        goto pcheck;
+                while(*s == '0')
+                        s++;
+                if (hexdig[*s])
+                        zret = 0;
+                havedig = 1;
+                s0 = s;
+                }
+        while(hexdig[*s])
+                s++;
+#ifdef USE_LOCALE
+        if (*s == *decimalpoint && !decpt) {
+                for(i = 1; decimalpoint[i]; ++i) {
+                        if (s[i] != decimalpoint[i])
+                                goto pcheck;
+                        }
+                decpt = s += i;
+#else
+        if (*s == '.' && !decpt) {
+                decpt = ++s;
+#endif
+                while(hexdig[*s])
+                        s++;
+                }/*}*/
+        if (decpt)
+                e = -(((Long)(s-decpt)) << 2);
+ pcheck:
+        s1 = s;
+        big = esign = 0;
+        switch(*s) {
+          case 'p':
+          case 'P':
+                switch(*++s) {
+                  case '-':
+                        esign = 1;
+                        /* no break */
+                  case '+':
+                        s++;
+                  }
+                if ((n = hexdig[*s]) == 0 || n > 0x19) {
+                        s = s1;
+                        break;
+                        }
+                e1 = n - 0x10;
+                while((n = hexdig[*++s]) !=0 && n <= 0x19) {
+                        if (e1 & 0xf8000000)
+                                big = 1;
+                        e1 = 10*e1 + n - 0x10;
+                        }
+                if (esign)
+                        e1 = -e1;
+                e += e1;
+          }
+        *sp = (char*)s;
+        if (!havedig)
+                *sp = (char*)s0 - 1;
+        if (zret)
+                goto retz1;
+        if (big) {
+                if (esign) {
+#ifdef IEEE_Arith
+                        switch(rounding) {
+                          case Round_up:
+                                if (sign)
+                                        break;
+                                goto ret_tiny;
+                          case Round_down:
+                                if (!sign)
+                                        break;
+                                goto ret_tiny;
+                          }
+#endif
+                        goto retz;
+#ifdef IEEE_Arith
+ ret_tiny:
+#ifndef NO_ERRNO
+                        errno = ERANGE;
+#endif
+                        word0(rvp) = 0;
+                        word1(rvp) = 1;
+                        return;
+#endif /* IEEE_Arith */
+                        }
+                switch(rounding) {
+                  case Round_near:
+                        goto ovfl1;
+                  case Round_up:
+                        if (!sign)
+                                goto ovfl1;
+                        goto ret_big;
+                  case Round_down:
+                        if (sign)
+                                goto ovfl1;
+                        goto ret_big;
+                  }
+ ret_big:
+                word0(rvp) = Big0;
+                word1(rvp) = Big1;
+                return;
+                }
+        n = s1 - s0 - 1;
+        for(k = 0; n > (1 << (kshift-2)) - 1; n >>= 1)
+                k++;
+        b = Balloc(k);
+        x = b->x;
+        n = 0;
+        L = 0;
+#ifdef USE_LOCALE
+        for(i = 0; decimalpoint[i+1]; ++i);
+#endif
+        while(s1 > s0) {
+#ifdef USE_LOCALE
+                if (*--s1 == decimalpoint[i]) {
+                        s1 -= i;
+                        continue;
+                        }
+#else
+                if (*--s1 == '.')
+                        continue;
+#endif
+                if (n == ULbits) {
+                        *x++ = L;
+                        L = 0;
+                        n = 0;
+                        }
+                L |= (hexdig[*s1] & 0x0f) << n;
+                n += 4;
+                }
+        *x++ = L;
+        b->wds = n = x - b->x;
+        n = ULbits*n - hi0bits(L);
+        nbits = Nbits;
+        lostbits = 0;
+        x = b->x;
+        if (n > nbits) {
+                n -= nbits;
+                if (any_on(b,n)) {
+                        lostbits = 1;
+                        k = n - 1;
+                        if (x[k>>kshift] & 1 << (k & kmask)) {
+                                lostbits = 2;
+                                if (k > 0 && any_on(b,k))
+                                        lostbits = 3;
+                                }
+                        }
+                rshift(b, n);
+                e += n;
+                }
+        else if (n < nbits) {
+                n = nbits - n;
+                b = lshift(b, n);
+                e -= n;
+                x = b->x;
+                }
+        if (e > Emax) {
+ ovfl:
+                Bfree(b);
+ ovfl1:
+#ifndef NO_ERRNO
+                errno = ERANGE;
+#endif
+                word0(rvp) = Exp_mask;
+                word1(rvp) = 0;
+                return;
+                }
+        denorm = 0;
+        if (e < emin) {
+                denorm = 1;
+                n = emin - e;
+                if (n >= nbits) {
+#ifdef IEEE_Arith /*{*/
+                        switch (rounding) {
+                          case Round_near:
+                                if (n == nbits && (n < 2 || any_on(b,n-1)))
+                                        goto ret_tiny;
+                                break;
+                          case Round_up:
+                                if (!sign)
+                                        goto ret_tiny;
+                                break;
+                          case Round_down:
+                                if (sign)
+                                        goto ret_tiny;
+                          }
+#endif /* } IEEE_Arith */
+                        Bfree(b);
+ retz:
+#ifndef NO_ERRNO
+                        errno = ERANGE;
+#endif
+ retz1:
+                        rvp->d = 0.;
+                        return;
+                        }
+                k = n - 1;
+                if (lostbits)
+                        lostbits = 1;
+                else if (k > 0)
+                        lostbits = any_on(b,k);
+                if (x[k>>kshift] & 1 << (k & kmask))
+                        lostbits |= 2;
+                nbits -= n;
+                rshift(b,n);
+                e = emin;
+                }
+        if (lostbits) {
+                up = 0;
+                switch(rounding) {
+                  case Round_zero:
+                        break;
+                  case Round_near:
+                        if (lostbits & 2
+                         && (lostbits & 1) | (x[0] & 1))
+                                up = 1;
+                        break;
+                  case Round_up:
+                        up = 1 - sign;
+                        break;
+                  case Round_down:
+                        up = sign;
+                  }
+                if (up) {
+                        k = b->wds;
+                        b = increment(b);
+                        x = b->x;
+                        if (denorm) {
+#if 0
+                                if (nbits == Nbits - 1
+                                 && x[nbits >> kshift] & 1 << (nbits & kmask))
+                                        denorm = 0; /* not currently used */
+#endif
+                                }
+                        else if (b->wds > k
+                         || ((n = nbits & kmask) !=0
+                             && hi0bits(x[k-1]) < 32-n)) {
+                                rshift(b,1);
+                                if (++e > Emax)
+                                        goto ovfl;
+                                }
+                        }
+                }
+#ifdef IEEE_Arith
+        if (denorm)
+                word0(rvp) = b->wds > 1 ? b->x[1] & ~0x100000 : 0;
+        else
+                word0(rvp) = (b->x[1] & ~0x100000) | ((e + 0x3ff + 52) << 20);
+        word1(rvp) = b->x[0];
+#endif
+#ifdef IBM
+        if ((j = e & 3)) {
+                k = b->x[0] & ((1 << j) - 1);
+                rshift(b,j);
+                if (k) {
+                        switch(rounding) {
+                          case Round_up:
+                                if (!sign)
+                                        increment(b);
+                                break;
+                          case Round_down:
+                                if (sign)
+                                        increment(b);
+                                break;
+                          case Round_near:
+                                j = 1 << (j-1);
+                                if (k & j && ((k & (j-1)) | lostbits))
+                                        increment(b);
+                          }
+                        }
+                }
+        e >>= 2;
+        word0(rvp) = b->x[1] | ((e + 65 + 13) << 24);
+        word1(rvp) = b->x[0];
+#endif
+#ifdef VAX
+        /* The next two lines ignore swap of low- and high-order 2 bytes. */
+        /* word0(rvp) = (b->x[1] & ~0x800000) | ((e + 129 + 55) << 23); */
+        /* word1(rvp) = b->x[0]; */
+        word0(rvp) = ((b->x[1] & ~0x800000) >> 16) | ((e + 129 + 55) << 7) | (b->x[1] << 16);
+        word1(rvp) = (b->x[0] >> 16) | (b->x[0] << 16);
+#endif
+        Bfree(b);
+        }
+#endif /*}!NO_HEX_FP*/
+
+ static int
+#ifdef KR_headers
+dshift(b, p2) Bigint *b; int p2;
+#else
+dshift(Bigint *b, int p2)
+#endif
+{
+        int rv = hi0bits(b->x[b->wds-1]) - 4;
+        if (p2 > 0)
+                rv -= p2;
+        return rv & kmask;
+        }
+
+ static int
+quorem
+#ifdef KR_headers
+        (b, S) Bigint *b, *S;
+#else
+        (Bigint *b, Bigint *S)
+#endif
+{
+        int n;
+        ULong *bx, *bxe, q, *sx, *sxe;
+#ifdef ULLong
+        ULLong borrow, carry, y, ys;
+#else
+        ULong borrow, carry, y, ys;
+#ifdef Pack_32
+        ULong si, z, zs;
+#endif
+#endif
+
+        n = S->wds;
+#ifdef DEBUG
+        /*debug*/ if (b->wds > n)
+        /*debug*/       Bug("oversize b in quorem");
+#endif
+        if (b->wds < n)
+                return 0;
+        sx = S->x;
+        sxe = sx + --n;
+        bx = b->x;
+        bxe = bx + n;
+        q = *bxe / (*sxe + 1);  /* ensure q <= true quotient */
+#ifdef DEBUG
+        /*debug*/ if (q > 9)
+        /*debug*/       Bug("oversized quotient in quorem");
+#endif
+        if (q) {
+                borrow = 0;
+                carry = 0;
+                do {
+#ifdef ULLong
+                        ys = *sx++ * (ULLong)q + carry;
+                        carry = ys >> 32;
+                        y = *bx - (ys & FFFFFFFF) - borrow;
+                        borrow = y >> 32 & (ULong)1;
+                        *bx++ = y & FFFFFFFF;
+#else
+#ifdef Pack_32
+                        si = *sx++;
+                        ys = (si & 0xffff) * q + carry;
+                        zs = (si >> 16) * q + (ys >> 16);
+                        carry = zs >> 16;
+                        y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
+                        borrow = (y & 0x10000) >> 16;
+                        z = (*bx >> 16) - (zs & 0xffff) - borrow;
+                        borrow = (z & 0x10000) >> 16;
+                        Storeinc(bx, z, y);
+#else
+                        ys = *sx++ * q + carry;
+                        carry = ys >> 16;
+                        y = *bx - (ys & 0xffff) - borrow;
+                        borrow = (y & 0x10000) >> 16;
+                        *bx++ = y & 0xffff;
+#endif
+#endif
+                        }
+                        while(sx <= sxe);
+                if (!*bxe) {
+                        bx = b->x;
+                        while(--bxe > bx && !*bxe)
+                                --n;
+                        b->wds = n;
+                        }
+                }
+        if (cmp(b, S) >= 0) {
+                q++;
+                borrow = 0;
+                carry = 0;
+                bx = b->x;
+                sx = S->x;
+                do {
+#ifdef ULLong
+                        ys = *sx++ + carry;
+                        carry = ys >> 32;
+                        y = *bx - (ys & FFFFFFFF) - borrow;
+                        borrow = y >> 32 & (ULong)1;
+                        *bx++ = y & FFFFFFFF;
+#else
+#ifdef Pack_32
+                        si = *sx++;
+                        ys = (si & 0xffff) + carry;
+                        zs = (si >> 16) + (ys >> 16);
+                        carry = zs >> 16;
+                        y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
+                        borrow = (y & 0x10000) >> 16;
+                        z = (*bx >> 16) - (zs & 0xffff) - borrow;
+                        borrow = (z & 0x10000) >> 16;
+                        Storeinc(bx, z, y);
+#else
+                        ys = *sx++ + carry;
+                        carry = ys >> 16;
+                        y = *bx - (ys & 0xffff) - borrow;
+                        borrow = (y & 0x10000) >> 16;
+                        *bx++ = y & 0xffff;
+#endif
+#endif
+                        }
+                        while(sx <= sxe);
+                bx = b->x;
+                bxe = bx + n;
+                if (!*bxe) {
+                        while(--bxe > bx && !*bxe)
+                                --n;
+                        b->wds = n;
+                        }
+                }
+        return q;
+        }
+
+#ifndef NO_STRTOD_BIGCOMP
+
+ static void
+bigcomp
+#ifdef KR_headers
+        (rv, s0, bc)
+        U *rv; CONST char *s0; BCinfo *bc;
+#else
+        (U *rv, CONST char *s0, BCinfo *bc)
+#endif
+{
+        Bigint *b, *d;
+        int b2, bbits, d2, dd, dig, dsign, i, j, nd, nd0, p2, p5, speccase;
+
+        dsign = bc->dsign;
+        nd = bc->nd;
+        nd0 = bc->nd0;
+        p5 = nd + bc->e0 - 1;
+        speccase = 0;
+#ifndef Sudden_Underflow
+        if (rv->d == 0.) {      /* special case: value near underflow-to-zero */
+                                /* threshold was rounded to zero */
+                b = i2b(1);
+                p2 = Emin - P + 1;
+                bbits = 1;
+#ifdef Avoid_Underflow
+                word0(rv) = (P+2) << Exp_shift;
+#else
+                word1(rv) = 1;
+#endif
+                i = 0;
+#ifdef Honor_FLT_ROUNDS
+                if (bc->rounding == 1)
+#endif
+                        {
+                        speccase = 1;
+                        --p2;
+                        dsign = 0;
+                        goto have_i;
+                        }
+                }
+        else
+#endif
+                b = d2b(rv, &p2, &bbits);
+#ifdef Avoid_Underflow
+        p2 -= bc->scale;
+#endif
+        /* floor(log2(rv)) == bbits - 1 + p2 */
+        /* Check for denormal case. */
+        i = P - bbits;
+        if (i > (j = P - Emin - 1 + p2)) {
+#ifdef Sudden_Underflow
+                Bfree(b);
+                b = i2b(1);
+                p2 = Emin;
+                i = P - 1;
+#ifdef Avoid_Underflow
+                word0(rv) = (1 + bc->scale) << Exp_shift;
+#else
+                word0(rv) = Exp_msk1;
+#endif
+                word1(rv) = 0;
+#else
+                i = j;
+#endif
+                }
+#ifdef Honor_FLT_ROUNDS
+        if (bc->rounding != 1) {
+                if (i > 0)
+                        b = lshift(b, i);
+                if (dsign)
+                        b = increment(b);
+                }
+        else
+#endif
+                {
+                b = lshift(b, ++i);
+                b->x[0] |= 1;
+                }
+#ifndef Sudden_Underflow
+ have_i:
+#endif
+        p2 -= p5 + i;
+        d = i2b(1);
+        /* Arrange for convenient computation of quotients:
+         * shift left if necessary so divisor has 4 leading 0 bits.
+         */
+        if (p5 > 0)
+                d = pow5mult(d, p5);
+        else if (p5 < 0)
+                b = pow5mult(b, -p5);
+        if (p2 > 0) {
+                b2 = p2;
+                d2 = 0;
+                }
+        else {
+                b2 = 0;
+                d2 = -p2;
+                }
+        i = dshift(d, d2);
+        if ((b2 += i) > 0)
+                b = lshift(b, b2);
+        if ((d2 += i) > 0)
+                d = lshift(d, d2);
+
+        /* Now b/d = exactly half-way between the two floating-point values */
+        /* on either side of the input string.  Compute first digit of b/d. */
+
+        if (!(dig = quorem(b,d))) {
+                b = multadd(b, 10, 0);  /* very unlikely */
+                dig = quorem(b,d);
+                }
+
+        /* Compare b/d with s0 */
+
+        for(i = 0; i < nd0; ) {
+                if ((dd = s0[i++] - '0' - dig))
+                        goto ret;
+                if (!b->x[0] && b->wds == 1) {
+                        if (i < nd)
+                                dd = 1;
+                        goto ret;
+                        }
+                b = multadd(b, 10, 0);
+                dig = quorem(b,d);
+                }
+        for(j = bc->dp1; i++ < nd;) {
+                if ((dd = s0[j++] - '0' - dig))
+                        goto ret;
+                if (!b->x[0] && b->wds == 1) {
+                        if (i < nd)
+                                dd = 1;
+                        goto ret;
+                        }
+                b = multadd(b, 10, 0);
+                dig = quorem(b,d);
+                }
+        if (b->x[0] || b->wds > 1)
+                dd = -1;
+ ret:
+        Bfree(b);
+        Bfree(d);
+#ifdef Honor_FLT_ROUNDS
+        if (bc->rounding != 1) {
+                if (dd < 0) {
+                        if (bc->rounding == 0) {
+                                if (!dsign)
+                                        goto retlow1;
+                                }
+                        else if (dsign)
+                                goto rethi1;
+                        }
+                else if (dd > 0) {
+                        if (bc->rounding == 0) {
+                                if (dsign)
+                                        goto rethi1;
+                                goto ret1;
+                                }
+                        if (!dsign)
+                                goto rethi1;
+                        dval(rv) += 2.*ulp(rv);
+                        }
+                else {
+                        bc->inexact = 0;
+                        if (dsign)
+                                goto rethi1;
+                        }
+                }
+        else
+#endif
+        if (speccase) {
+                if (dd <= 0)
+                        rv->d = 0.;
+                }
+        else if (dd < 0) {
+                if (!dsign)     /* does not happen for round-near */
+retlow1:
+                        dval(rv) -= ulp(rv);
+                }
+        else if (dd > 0) {
+                if (dsign) {
+ rethi1:
+                        dval(rv) += ulp(rv);
+                        }
+                }
+        else {
+                /* Exact half-way case:  apply round-even rule. */
+                if (word1(rv) & 1) {
+                        if (dsign)
+                                goto rethi1;
+                        goto retlow1;
+                        }
+                }
+
+#ifdef Honor_FLT_ROUNDS
+ ret1:
+#endif
+        return;
+        }
+#endif /* NO_STRTOD_BIGCOMP */
+
  double
 strtod
 #ifdef KR_headers
         (s00, se) CONST char *s00; char **se;
 #else
         (CONST char *s00, char **se)
 #endif
 {
-#ifdef Avoid_Underflow
-        int scale;
-#endif
-        int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, dsign,
-                 e, e1, esign, i, j, k, nd, nd0, nf, nz, nz0, sign;
+        int bb2, bb5, bbe, bd2, bd5, bbbits, bs2, c, e, e1;
+        int esign, i, j, k, nd, nd0, nf, nz, nz0, sign;
         CONST char *s, *s0, *s1;
-        double aadj, aadj1, adj, rv, rv0;
+        double aadj, aadj1;
         Long L;
+        U aadj2, adj, rv, rv0;
         ULong y, z;
+        BCinfo bc;
         Bigint *bb, *bb1, *bd, *bd0, *bs, *delta;
 #ifdef SET_INEXACT
-        int inexact, oldinexact;
+        int oldinexact;
 #endif
 #ifdef Honor_FLT_ROUNDS /*{*/
-        int Rounding;
 #ifdef Trust_FLT_ROUNDS /*{{ only define this if FLT_ROUNDS really works! */
-        Rounding = Flt_Rounds;
+        bc.rounding = Flt_Rounds;
 #else /*}{*/
-        Rounding = 1;
+        bc.rounding = 1;
         switch(fegetround()) {
-          case FE_TOWARDZERO:   Rounding = 0; break;
-          case FE_UPWARD:       Rounding = 2; break;
-          case FE_DOWNWARD:     Rounding = 3;
+          case FE_TOWARDZERO:   bc.rounding = 0; break;
+          case FE_UPWARD:       bc.rounding = 2; break;
+          case FE_DOWNWARD:     bc.rounding = 3;
           }
 #endif /*}}*/
 #endif /*}*/
 #ifdef USE_LOCALE
         CONST char *s2;
 #endif
 
-        sign = nz0 = nz = 0;
-        dval(rv) = 0.;
+        sign = nz0 = nz = bc.dplen = bc.uflchk = 0;
+        dval(&rv) = 0.;
         for(s = s00;;s++) switch(*s) {
                 case '-':
                         sign = 1;
                         /* no break */
                 case '+':
                         if (*++s)
                                 goto break2;
                         /* no break */
                 case 0:
                         goto ret0;
                 case '\t':
                 case '\n':
                 case '\v':
                 case '\f':
                 case '\r':
                 case ' ':
                         continue;
                 default:
                         goto break2;
                 }
  break2:
         if (*s == '0') {
+#ifndef NO_HEX_FP /*{*/
+                switch(s[1]) {
+                  case 'x':
+                  case 'X':
+#ifdef Honor_FLT_ROUNDS
+                        gethex(&s, &rv, bc.rounding, sign);
+#else
+                        gethex(&s, &rv, 1, sign);
+#endif
+                        goto ret;
+                  }
+#endif /*}*/
                 nz0 = 1;
                 while(*++s == '0') ;
                 if (!*s)
                         goto ret;
                 }
         s0 = s;
         y = z = 0;
         for(nd = nf = 0; (c = *s) >= '0' && c <= '9'; nd++, s++)
                 if (nd < 9)
                         y = 10*y + c - '0';
                 else if (nd < 16)
                         z = 10*z + c - '0';
         nd0 = nd;
+        bc.dp0 = bc.dp1 = s - s0;
 #ifdef USE_LOCALE
         s1 = localeconv()->decimal_point;
         if (c == *s1) {
                 c = '.';
                 if (*++s1) {
                         s2 = s;
                         for(;;) {
                                 if (*++s2 != *s1) {
                                         c = 0;
                                         break;
                                         }
                                 if (!*++s1) {
                                         s = s2;
                                         break;
                                         }
                                 }
                         }
                 }
 #endif
         if (c == '.') {
                 c = *++s;
+                bc.dp1 = s - s0;
+                bc.dplen = bc.dp1 - bc.dp0;
                 if (!nd) {
                         for(; c == '0'; c = *++s)
                                 nz++;
                         if (c > '0' && c <= '9') {
                                 s0 = s;
                                 nf += nz;
                                 nz = 0;
                                 goto have_dig;
                                 }
                         goto dig_done;
@@ skipping 51 matching lines @@
                         else
                                 e = 0;
                         }
                 else
                         s = s00;
                 }
         if (!nd) {
                 if (!nz && !nz0) {
 #ifdef INFNAN_CHECK
                         /* Check for Nan and Infinity */
-                        switch(c) {
+                        if (!bc.dplen)
+                         switch(c) {
                           case 'i':
                           case 'I':
                                 if (match(&s,"nf")) {
                                         --s;
                                         if (!match(&s,"inity"))
                                                 ++s;
-                                        word0(rv) = 0x7ff00000;
-                                        word1(rv) = 0;
+                                        word0(&rv) = 0x7ff00000;
+                                        word1(&rv) = 0;
                                         goto ret;
                                         }
                                 break;
                           case 'n':
                           case 'N':
                                 if (match(&s, "an")) {
-                                        word0(rv) = NAN_WORD0;
-                                        word1(rv) = NAN_WORD1;
+                                        word0(&rv) = NAN_WORD0;
+                                        word1(&rv) = NAN_WORD1;
 #ifndef No_Hex_NaN
                                         if (*s == '(') /*)*/
                                                 hexnan(&rv, &s);
 #endif
                                         goto ret;
                                         }
                           }
 #endif /* INFNAN_CHECK */
  ret0:
                         s = s00;
                         sign = 0;
                         }
                 goto ret;
                 }
-        e1 = e -= nf;
+        bc.e0 = e1 = e -= nf;
 
         /* Now we have nd0 digits, starting at s0, followed by a
          * decimal point, followed by nd-nd0 digits.  The number we're
          * after is the integer represented by those digits times
          * 10**e */
 
         if (!nd0)
                 nd0 = nd;
         k = nd < DBL_DIG + 1 ? nd : DBL_DIG + 1;
-        dval(rv) = y;
+        dval(&rv) = y;
         if (k > 9) {
 #ifdef SET_INEXACT
                 if (k > DBL_DIG)
                         oldinexact = get_inexact();
 #endif
-                dval(rv) = tens[k - 9] * dval(rv) + z;
+                dval(&rv) = tens[k - 9] * dval(&rv) + z;
                 }
         bd0 = 0;
         if (nd <= DBL_DIG
 #ifndef RND_PRODQUOT
 #ifndef Honor_FLT_ROUNDS
                 && Flt_Rounds == 1
 #endif
 #endif
                         ) {
                 if (!e)
                         goto ret;
                 if (e > 0) {
                         if (e <= Ten_pmax) {
 #ifdef VAX
                                 goto vax_ovfl_check;
 #else
 #ifdef Honor_FLT_ROUNDS
                                 /* round correctly FLT_ROUNDS = 2 or 3 */
                                 if (sign) {
-                                        rv = -rv;
+                                        rv.d = -rv.d;
                                         sign = 0;
                                         }
 #endif
-                                /* rv = */ rounded_product(dval(rv), tens[e]);
+                                /* rv = */ rounded_product(dval(&rv), tens[e]);
                                 goto ret;
 #endif
                                 }
                         i = DBL_DIG - nd;
                         if (e <= Ten_pmax + i) {
                                 /* A fancier test would sometimes let us do
                                  * this for larger i values.
                                  */
 #ifdef Honor_FLT_ROUNDS
                                 /* round correctly FLT_ROUNDS = 2 or 3 */
                                 if (sign) {
-                                        rv = -rv;
+                                        rv.d = -rv.d;
                                         sign = 0;
                                         }
 #endif
                                 e -= i;
-                                dval(rv) *= tens[i];
+                                dval(&rv) *= tens[i];
 #ifdef VAX
                                 /* VAX exponent range is so narrow we must
                                  * worry about overflow here...
                                  */
  vax_ovfl_check:
-                                word0(rv) -= P*Exp_msk1;
-                                /* rv = */ rounded_product(dval(rv), tens[e]);
-                                if ((word0(rv) & Exp_mask)
+                                word0(&rv) -= P*Exp_msk1;
+                                /* rv = */ rounded_product(dval(&rv), tens[e]);
+                                if ((word0(&rv) & Exp_mask)
                                  > Exp_msk1*(DBL_MAX_EXP+Bias-1-P))
                                         goto ovfl;
-                                word0(rv) += P*Exp_msk1;
+                                word0(&rv) += P*Exp_msk1;
 #else
-                                /* rv = */ rounded_product(dval(rv), tens[e]);
+                                /* rv = */ rounded_product(dval(&rv), tens[e]);
 #endif
                                 goto ret;
                                 }
                         }
 #ifndef Inaccurate_Divide
                 else if (e >= -Ten_pmax) {
 #ifdef Honor_FLT_ROUNDS
                         /* round correctly FLT_ROUNDS = 2 or 3 */
                         if (sign) {
-                                rv = -rv;
+                                rv.d = -rv.d;
                                 sign = 0;
                                 }
 #endif
-                        /* rv = */ rounded_quotient(dval(rv), tens[-e]);
+                        /* rv = */ rounded_quotient(dval(&rv), tens[-e]);
                         goto ret;
                         }
 #endif
                 }
         e1 += nd - k;
 
 #ifdef IEEE_Arith
 #ifdef SET_INEXACT
-        inexact = 1;
+        bc.inexact = 1;
         if (k <= DBL_DIG)
                 oldinexact = get_inexact();
 #endif
 #ifdef Avoid_Underflow
-        scale = 0;
+        bc.scale = 0;
 #endif
 #ifdef Honor_FLT_ROUNDS
-        if (Rounding >= 2) {
+        if (bc.rounding >= 2) {
                 if (sign)
-                        Rounding = Rounding == 2 ? 0 : 2;
+                        bc.rounding = bc.rounding == 2 ? 0 : 2;
                 else
-                        if (Rounding != 2)
-                                Rounding = 0;
+                        if (bc.rounding != 2)
+                                bc.rounding = 0;
                 }
 #endif
 #endif /*IEEE_Arith*/
 
         /* Get starting approximation = rv * 10**e1 */
 
         if (e1 > 0) {
                 if ((i = e1 & 15))
-                        dval(rv) *= tens[i];
+                        dval(&rv) *= tens[i];
                 if (e1 &= ~15) {
                         if (e1 > DBL_MAX_10_EXP) {
  ovfl:
 #ifndef NO_ERRNO
                                 errno = ERANGE;
 #endif
                                 /* Can't trust HUGE_VAL */
 #ifdef IEEE_Arith
 #ifdef Honor_FLT_ROUNDS
-                                switch(Rounding) {
+                                switch(bc.rounding) {
                                   case 0: /* toward 0 */
                                   case 3: /* toward -infinity */
-                                        word0(rv) = Big0;
-                                        word1(rv) = Big1;
+                                        word0(&rv) = Big0;
+                                        word1(&rv) = Big1;
                                         break;
                                   default:
-                                        word0(rv) = Exp_mask;
-                                        word1(rv) = 0;
+                                        word0(&rv) = Exp_mask;
+                                        word1(&rv) = 0;
                                   }
 #else /*Honor_FLT_ROUNDS*/
-                                word0(rv) = Exp_mask;
-                                word1(rv) = 0;
+                                word0(&rv) = Exp_mask;
+                                word1(&rv) = 0;
 #endif /*Honor_FLT_ROUNDS*/
 #ifdef SET_INEXACT
                                 /* set overflow bit */
-                                dval(rv0) = 1e300;
-                                dval(rv0) *= dval(rv0);
+                                dval(&rv0) = 1e300;
+                                dval(&rv0) *= dval(&rv0);
 #endif
 #else /*IEEE_Arith*/
-                                word0(rv) = Big0;
-                                word1(rv) = Big1;
+                                word0(&rv) = Big0;
+                                word1(&rv) = Big1;
 #endif /*IEEE_Arith*/
-                                if (bd0)
-                                        goto retfree;
                                 goto ret;
                                 }
                         e1 >>= 4;
                         for(j = 0; e1 > 1; j++, e1 >>= 1)
                                 if (e1 & 1)
-                                        dval(rv) *= bigtens[j];
+                                        dval(&rv) *= bigtens[j];
                 /* The last multiplication could overflow. */
-                        word0(rv) -= P*Exp_msk1;
-                        dval(rv) *= bigtens[j];
-                        if ((z = word0(rv) & Exp_mask)
+                        word0(&rv) -= P*Exp_msk1;
+                        dval(&rv) *= bigtens[j];
+                        if ((z = word0(&rv) & Exp_mask)
                          > Exp_msk1*(DBL_MAX_EXP+Bias-P))
                                 goto ovfl;
                         if (z > Exp_msk1*(DBL_MAX_EXP+Bias-1-P)) {
                                 /* set to largest number */
                                 /* (Can't trust DBL_MAX) */
-                                word0(rv) = Big0;
-                                word1(rv) = Big1;
+                                word0(&rv) = Big0;
+                                word1(&rv) = Big1;
                                 }
                         else
-                                word0(rv) += P*Exp_msk1;
+                                word0(&rv) += P*Exp_msk1;
                         }
                 }
         else if (e1 < 0) {
                 e1 = -e1;
                 if ((i = e1 & 15))
-                        dval(rv) /= tens[i];
+                        dval(&rv) /= tens[i];
                 if (e1 >>= 4) {
                         if (e1 >= 1 << n_bigtens)
                                 goto undfl;
 #ifdef Avoid_Underflow
                         if (e1 & Scale_Bit)
-                                scale = 2*P;
+                                bc.scale = 2*P;
                         for(j = 0; e1 > 0; j++, e1 >>= 1)
                                 if (e1 & 1)
-                                        dval(rv) *= tinytens[j];
-                        if (scale && (j = 2*P + 1 - ((word0(rv) & Exp_mask)
+                                        dval(&rv) *= tinytens[j];
+                        if (bc.scale && (j = 2*P + 1 - ((word0(&rv) & Exp_mask)
                                                 >> Exp_shift)) > 0) {
                                 /* scaled rv is denormal; clear j low bits */
                                 if (j >= 32) {
-                                        word1(rv) = 0;
+                                        word1(&rv) = 0;
                                         if (j >= 53)
-                                         word0(rv) = (P+2)*Exp_msk1;
+                                         word0(&rv) = (P+2)*Exp_msk1;
                                         else
-                                         word0(rv) &= 0xffffffff << j-32;
+                                         word0(&rv) &= 0xffffffff << (j-32);
                                         }
                                 else
-                                        word1(rv) &= 0xffffffff << j;
+                                        word1(&rv) &= 0xffffffff << j;
                                 }
 #else
                         for(j = 0; e1 > 1; j++, e1 >>= 1)
                                 if (e1 & 1)
-                                        dval(rv) *= tinytens[j];
+                                        dval(&rv) *= tinytens[j];
                         /* The last multiplication could underflow. */
-                        dval(rv0) = dval(rv);
-                        dval(rv) *= tinytens[j];
-                        if (!dval(rv)) {
-                                dval(rv) = 2.*dval(rv0);
-                                dval(rv) *= tinytens[j];
+                        dval(&rv0) = dval(&rv);
+                        dval(&rv) *= tinytens[j];
+                        if (!dval(&rv)) {
+                                dval(&rv) = 2.*dval(&rv0);
+                                dval(&rv) *= tinytens[j];
 #endif
-                                if (!dval(rv)) {
+                                if (!dval(&rv)) {
  undfl:
-                                        dval(rv) = 0.;
+                                        dval(&rv) = 0.;
 #ifndef NO_ERRNO
                                         errno = ERANGE;
 #endif
-                                        if (bd0)
-                                                goto retfree;
                                         goto ret;
                                         }
 #ifndef Avoid_Underflow
-                                word0(rv) = Tiny0;
-                                word1(rv) = Tiny1;
+                                word0(&rv) = Tiny0;
+                                word1(&rv) = Tiny1;
                                 /* The refinement below will clean
                                  * this approximation up.
                                  */
                                 }
 #endif
                         }
                 }
 
         /* Now the hard part -- adjusting rv to the correct value.*/
 
         /* Put digits into bd: true value = bd * 10^e */
 
-        bd0 = s2b(s0, nd0, nd, y);
+        bc.nd = nd;
+#ifndef NO_STRTOD_BIGCOMP
+        bc.nd0 = nd0;   /* Only needed if nd > strtod_diglim, but done here */
+                        /* to silence an erroneous warning about bc.nd0 */
+                        /* possibly not being initialized. */
+        if (nd > strtod_diglim) {
+                /* ASSERT(strtod_diglim >= 18); 18 == one more than the */
+                /* minimum number of decimal digits to distinguish double values */
+                /* in IEEE arithmetic. */
+                i = j = 18;
+                if (i > nd0)
+                        j += bc.dplen;
+                for(;;) {
+                        if (--j <= bc.dp1 && j >= bc.dp0)
+                                j = bc.dp0 - 1;
+                        if (s0[j] != '0')
+                                break;
+                        --i;
+                        }
+                e += nd - i;
+                nd = i;
+                if (nd0 > nd)
+                        nd0 = nd;
+                if (nd < 9) { /* must recompute y */
+                        y = 0;
+                        for(i = 0; i < nd0; ++i)
+                                y = 10*y + s0[i] - '0';
+                        for(j = bc.dp1; i < nd; ++i)
+                                y = 10*y + s0[j++] - '0';
+                        }
+                }
+#endif
+        bd0 = s2b(s0, nd0, nd, y, bc.dplen);
 
         for(;;) {
                 bd = Balloc(bd0->k);
                 Bcopy(bd, bd0);
-                bb = d2b(dval(rv), &bbe, &bbbits);      /* rv = bb * 2^bbe */
+                bb = d2b(&rv, &bbe, &bbbits);   /* rv = bb * 2^bbe */
                 bs = i2b(1);
 
                 if (e >= 0) {
                         bb2 = bb5 = 0;
                         bd2 = bd5 = e;
                         }
                 else {
                         bb2 = bb5 = -e;
                         bd2 = bd5 = 0;
                         }
                 if (bbe >= 0)
                         bb2 += bbe;
                 else
                         bd2 -= bbe;
                 bs2 = bb2;
 #ifdef Honor_FLT_ROUNDS
-                if (Rounding != 1)
+                if (bc.rounding != 1)
                         bs2++;
 #endif
 #ifdef Avoid_Underflow
-                j = bbe - scale;
+                j = bbe - bc.scale;
                 i = j + bbbits - 1;     /* logb(rv) */
                 if (i < Emin)   /* denormal */
                         j += P - Emin;
                 else
                         j = P + 1 - bbbits;
 #else /*Avoid_Underflow*/
 #ifdef Sudden_Underflow
 #ifdef IBM
                 j = 1 + 4*P - 3 - bbbits + ((bbe + bbbits - 1) & 3);
 #else
                 j = P + 1 - bbbits;
 #endif
 #else /*Sudden_Underflow*/
                 j = bbe;
                 i = j + bbbits - 1;     /* logb(rv) */
                 if (i < Emin)   /* denormal */
                         j += P - Emin;
                 else
                         j = P + 1 - bbbits;
 #endif /*Sudden_Underflow*/
 #endif /*Avoid_Underflow*/
                 bb2 += j;
                 bd2 += j;
 #ifdef Avoid_Underflow
-                bd2 += scale;
+                bd2 += bc.scale;
 #endif
                 i = bb2 < bd2 ? bb2 : bd2;
                 if (i > bs2)
                         i = bs2;
                 if (i > 0) {
                         bb2 -= i;
                         bd2 -= i;
                         bs2 -= i;
                         }
                 if (bb5 > 0) {
                         bs = pow5mult(bs, bb5);
                         bb1 = mult(bs, bb);
                         Bfree(bb);
                         bb = bb1;
                         }
                 if (bb2 > 0)
                         bb = lshift(bb, bb2);
                 if (bd5 > 0)
                         bd = pow5mult(bd, bd5);
                 if (bd2 > 0)
                         bd = lshift(bd, bd2);
                 if (bs2 > 0)
                         bs = lshift(bs, bs2);
                 delta = diff(bb, bd);
-                dsign = delta->sign;
+                bc.dsign = delta->sign;
                 delta->sign = 0;
                 i = cmp(delta, bs);
+#ifndef NO_STRTOD_BIGCOMP
+                if (bc.nd > nd && i <= 0) {
+                        if (bc.dsign)
+                                break;  /* Must use bigcomp(). */
 #ifdef Honor_FLT_ROUNDS
-                if (Rounding != 1) {
+                        if (bc.rounding != 1) {
+                                if (i < 0)
+                                        break;
+                                }
+                        else
+#endif
+                                {
+                                bc.nd = nd;
+                                i = -1; /* Discarded digits make delta smaller. */
+                                }
+                        }
+#endif
+#ifdef Honor_FLT_ROUNDS
+                if (bc.rounding != 1) {
                         if (i < 0) {
                                 /* Error is less than an ulp */
                                 if (!delta->x[0] && delta->wds <= 1) {
                                         /* exact */
 #ifdef SET_INEXACT
-                                        inexact = 0;
+                                        bc.inexact = 0;
 #endif
                                         break;
                                         }
-                                if (Rounding) {
-                                        if (dsign) {
-                                                adj = 1.;
+                                if (bc.rounding) {
+                                        if (bc.dsign) {
+                                                adj.d = 1.;
                                                 goto apply_adj;
                                                 }
                                         }
-                                else if (!dsign) {
-                                        adj = -1.;
-                                        if (!word1(rv)
-                                         && !(word0(rv) & Frac_mask)) {
-                                                y = word0(rv) & Exp_mask;
+                                else if (!bc.dsign) {
+                                        adj.d = -1.;
+                                        if (!word1(&rv)
+                                         && !(word0(&rv) & Frac_mask)) {
+                                                y = word0(&rv) & Exp_mask;
 #ifdef Avoid_Underflow
-                                                if (!scale || y > 2*P*Exp_msk1)
+                                                if (!bc.scale || y > 2*P*Exp_msk1)
 #else
                                                 if (y)
 #endif
                                                   {
                                                   delta = lshift(delta,Log2P);
                                                   if (cmp(delta, bs) <= 0)
-                                                        adj = -0.5;
+                                                        adj.d = -0.5;
                                                   }
                                                 }
  apply_adj:
 #ifdef Avoid_Underflow
-                                        if (scale && (y = word0(rv) & Exp_mask)
+                                        if (bc.scale && (y = word0(&rv) & Exp_mask)
                                                 <= 2*P*Exp_msk1)
-                                          word0(adj) += (2*P+1)*Exp_msk1 - y;
+                                          word0(&adj) += (2*P+1)*Exp_msk1 - y;
 #else
 #ifdef Sudden_Underflow
-                                        if ((word0(rv) & Exp_mask) <=
+                                        if ((word0(&rv) & Exp_mask) <=
                                                         P*Exp_msk1) {
-                                                word0(rv) += P*Exp_msk1;
-                                                dval(rv) += adj*ulp(dval(rv));
-                                                word0(rv) -= P*Exp_msk1;
+                                                word0(&rv) += P*Exp_msk1;
+                                                dval(&rv) += adj.d*ulp(dval(&rv));
+                                                word0(&rv) -= P*Exp_msk1;
                                                 }
                                         else
 #endif /*Sudden_Underflow*/
 #endif /*Avoid_Underflow*/
-                                        dval(rv) += adj*ulp(dval(rv));
+                                        dval(&rv) += adj.d*ulp(&rv);
                                         }
                                 break;
                                 }
-                        adj = ratio(delta, bs);
-                        if (adj < 1.)
-                                adj = 1.;
-                        if (adj <= 0x7ffffffe) {
+                        adj.d = ratio(delta, bs);
+                        if (adj.d < 1.)
+                                adj.d = 1.;
+                        if (adj.d <= 0x7ffffffe) {
                                 /* adj = rounding ? ceil(adj) : floor(adj); */
-                                y = adj;
-                                if (y != adj) {
-                                        if (!((Rounding>>1) ^ dsign))
+                                y = adj.d;
+                                if (y != adj.d) {
+                                        if (!((bc.rounding>>1) ^ bc.dsign))
                                                 y++;
-                                        adj = y;
+                                        adj.d = y;
                                         }
                                 }
 #ifdef Avoid_Underflow
-                        if (scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1)
-                                word0(adj) += (2*P+1)*Exp_msk1 - y;
+                        if (bc.scale && (y = word0(&rv) & Exp_mask) <= 2*P*Exp_msk1)
+                                word0(&adj) += (2*P+1)*Exp_msk1 - y;
 #else
 #ifdef Sudden_Underflow
-                        if ((word0(rv) & Exp_mask) <= P*Exp_msk1) {
-                                word0(rv) += P*Exp_msk1;
-                                adj *= ulp(dval(rv));
-                                if (dsign)
-                                        dval(rv) += adj;
+                        if ((word0(&rv) & Exp_mask) <= P*Exp_msk1) {
+                                word0(&rv) += P*Exp_msk1;
+                                adj.d *= ulp(dval(&rv));
+                                if (bc.dsign)
+                                        dval(&rv) += adj.d;
                                 else
-                                        dval(rv) -= adj;
-                                word0(rv) -= P*Exp_msk1;
+                                        dval(&rv) -= adj.d;
+                                word0(&rv) -= P*Exp_msk1;
                                 goto cont;
                                 }
 #endif /*Sudden_Underflow*/
 #endif /*Avoid_Underflow*/
-                        adj *= ulp(dval(rv));
-                        if (dsign) {
-                                if (word0(rv) == Big0 && word1(rv) == Big1)
+                        adj.d *= ulp(&rv);
+                        if (bc.dsign) {
+                                if (word0(&rv) == Big0 && word1(&rv) == Big1)
                                         goto ovfl;
-                                dval(rv) += adj;
+                                dval(&rv) += adj.d;
                                 }
                         else
-                                dval(rv) -= adj;
+                                dval(&rv) -= adj.d;
                         goto cont;
                         }
 #endif /*Honor_FLT_ROUNDS*/
 
                 if (i < 0) {
                         /* Error is less than half an ulp -- check for
                          * special case of mantissa a power of two.
                          */
-                        if (dsign || word1(rv) || word0(rv) & Bndry_mask
+                        if (bc.dsign || word1(&rv) || word0(&rv) & Bndry_mask
 #ifdef IEEE_Arith
 #ifdef Avoid_Underflow
-                         || (word0(rv) & Exp_mask) <= (2*P+1)*Exp_msk1
+                         || (word0(&rv) & Exp_mask) <= (2*P+1)*Exp_msk1
 #else
-                         || (word0(rv) & Exp_mask) <= Exp_msk1
+                         || (word0(&rv) & Exp_mask) <= Exp_msk1
 #endif
 #endif
                                 ) {
 #ifdef SET_INEXACT
                                 if (!delta->x[0] && delta->wds <= 1)
-                                        inexact = 0;
+                                        bc.inexact = 0;
 #endif
                                 break;
                                 }
                         if (!delta->x[0] && delta->wds <= 1) {
                                 /* exact result */
 #ifdef SET_INEXACT
-                                inexact = 0;
+                                bc.inexact = 0;
 #endif
                                 break;
                                 }
                         delta = lshift(delta,Log2P);
                         if (cmp(delta, bs) > 0)
                                 goto drop_down;
                         break;
                         }
                 if (i == 0) {
                         /* exactly half-way between */
-                        if (dsign) {
-                                if ((word0(rv) & Bndry_mask1) == Bndry_mask1
-                                 &&  word1(rv) == (
+                        if (bc.dsign) {
+                                if ((word0(&rv) & Bndry_mask1) == Bndry_mask1
+                                 &&  word1(&rv) == (
 #ifdef Avoid_Underflow
-                        (scale && (y = word0(rv) & Exp_mask) <= 2*P*Exp_msk1)
+                        (bc.scale && (y = word0(&rv) & Exp_mask) <= 2*P*Exp_msk1)
                 ? (0xffffffff & (0xffffffff << (2*P+1-(y>>Exp_shift)))) :
 #endif
                                                    0xffffffff)) {
                                         /*boundary case -- increment exponent*/
-                                        word0(rv) = (word0(rv) & Exp_mask)
+                                        word0(&rv) = (word0(&rv) & Exp_mask)
                                                 + Exp_msk1
 #ifdef IBM
                                                 | Exp_msk1 >> 4
 #endif
                                                 ;
-                                        word1(rv) = 0;
+                                        word1(&rv) = 0;
 #ifdef Avoid_Underflow
-                                        dsign = 0;
+                                        bc.dsign = 0;
 #endif
                                         break;
                                         }
                                 }
-                        else if (!(word0(rv) & Bndry_mask) && !word1(rv)) {
+                        else if (!(word0(&rv) & Bndry_mask) && !word1(&rv)) {
  drop_down:
                                 /* boundary case -- decrement exponent */
 #ifdef Sudden_Underflow /*{{*/
-                                L = word0(rv) & Exp_mask;
+                                L = word0(&rv) & Exp_mask;
 #ifdef IBM
                                 if (L <  Exp_msk1)
 #else
 #ifdef Avoid_Underflow
-                                if (L <= (scale ? (2*P+1)*Exp_msk1 : Exp_msk1))
+                                if (L <= (bc.scale ? (2*P+1)*Exp_msk1 : Exp_msk1))
 #else
                                 if (L <= Exp_msk1)
 #endif /*Avoid_Underflow*/
 #endif /*IBM*/
+                                        {
+                                        if (bc.nd >nd) {
+                                                bc.uflchk = 1;
+                                                break;
+                                                }
                                         goto undfl;
+                                        }
                                 L -= Exp_msk1;
 #else /*Sudden_Underflow}{*/
 #ifdef Avoid_Underflow
-                                if (scale) {
-                                        L = word0(rv) & Exp_mask;
+                                if (bc.scale) {
+                                        L = word0(&rv) & Exp_mask;
                                         if (L <= (2*P+1)*Exp_msk1) {
                                                 if (L > (P+2)*Exp_msk1)
                                                         /* round even ==> */
                                                         /* accept rv */
                                                         break;
                                                 /* rv = smallest denormal */
+                                                if (bc.nd >nd) {
+                                                        bc.uflchk = 1;
+                                                        break;
+                                                        }
                                                 goto undfl;
                                                 }
                                         }
 #endif /*Avoid_Underflow*/
-                                L = (word0(rv) & Exp_mask) - Exp_msk1;
+                                L = (word0(&rv) & Exp_mask) - Exp_msk1;
 #endif /*Sudden_Underflow}}*/
-                                word0(rv) = L | Bndry_mask1;
-                                word1(rv) = 0xffffffff;
+                                word0(&rv) = L | Bndry_mask1;
+                                word1(&rv) = 0xffffffff;
 #ifdef IBM
                                 goto cont;
 #else
                                 break;
 #endif
                                 }
 #ifndef ROUND_BIASED
-                        if (!(word1(rv) & LSB))
+                        if (!(word1(&rv) & LSB))
                                 break;
 #endif
-                        if (dsign)
-                                dval(rv) += ulp(dval(rv));
+                        if (bc.dsign)
+                                dval(&rv) += ulp(&rv);
 #ifndef ROUND_BIASED
                         else {
-                                dval(rv) -= ulp(dval(rv));
+                                dval(&rv) -= ulp(&rv);
 #ifndef Sudden_Underflow
-                                if (!dval(rv))
+                                if (!dval(&rv)) {
+                                        if (bc.nd >nd) {
+                                                bc.uflchk = 1;
+                                                break;
+                                                }
                                         goto undfl;
+                                        }
 #endif
                                 }
 #ifdef Avoid_Underflow
-                        dsign = 1 - dsign;
+                        bc.dsign = 1 - bc.dsign;
 #endif
 #endif
                         break;
                         }
                 if ((aadj = ratio(delta, bs)) <= 2.) {
-                        if (dsign)
+                        if (bc.dsign)
                                 aadj = aadj1 = 1.;
-                        else if (word1(rv) || word0(rv) & Bndry_mask) {
+                        else if (word1(&rv) || word0(&rv) & Bndry_mask) {
 #ifndef Sudden_Underflow
-                                if (word1(rv) == Tiny1 && !word0(rv))
+                                if (word1(&rv) == Tiny1 && !word0(&rv)) {
+                                        if (bc.nd >nd) {
+                                                bc.uflchk = 1;
+                                                break;
+                                                }
                                         goto undfl;
+                                        }
 #endif
                                 aadj = 1.;
                                 aadj1 = -1.;
                                 }
                         else {
                                 /* special case -- power of FLT_RADIX to be */
                                 /* rounded down... */
 
                                 if (aadj < 2./FLT_RADIX)
                                         aadj = 1./FLT_RADIX;
                                 else
                                         aadj *= 0.5;
                                 aadj1 = -aadj;
                                 }
                         }
                 else {
                         aadj *= 0.5;
-                        aadj1 = dsign ? aadj : -aadj;
+                        aadj1 = bc.dsign ? aadj : -aadj;
 #ifdef Check_FLT_ROUNDS
-                        switch(Rounding) {
+                        switch(bc.rounding) {
                                 case 2: /* towards +infinity */
                                         aadj1 -= 0.5;
                                         break;
                                 case 0: /* towards 0 */
                                 case 3: /* towards -infinity */
                                         aadj1 += 0.5;
                                 }
 #else
                         if (Flt_Rounds == 0)
                                 aadj1 += 0.5;
 #endif /*Check_FLT_ROUNDS*/
                         }
-                y = word0(rv) & Exp_mask;
+                y = word0(&rv) & Exp_mask;
 
                 /* Check for overflow */
 
                 if (y == Exp_msk1*(DBL_MAX_EXP+Bias-1)) {
-                        dval(rv0) = dval(rv);
-                        word0(rv) -= P*Exp_msk1;
-                        adj = aadj1 * ulp(dval(rv));
-                        dval(rv) += adj;
-                        if ((word0(rv) & Exp_mask) >=
+                        dval(&rv0) = dval(&rv);
+                        word0(&rv) -= P*Exp_msk1;
+                        adj.d = aadj1 * ulp(&rv);
+                        dval(&rv) += adj.d;
+                        if ((word0(&rv) & Exp_mask) >=
                                         Exp_msk1*(DBL_MAX_EXP+Bias-P)) {
-                                if (word0(rv0) == Big0 && word1(rv0) == Big1)
+                                if (word0(&rv0) == Big0 && word1(&rv0) == Big1)
                                         goto ovfl;
-                                word0(rv) = Big0;
-                                word1(rv) = Big1;
+                                word0(&rv) = Big0;
+                                word1(&rv) = Big1;
                                 goto cont;
                                 }
                         else
-                                word0(rv) += P*Exp_msk1;
+                                word0(&rv) += P*Exp_msk1;
                         }
                 else {
 #ifdef Avoid_Underflow
-                        if (scale && y <= 2*P*Exp_msk1) {
+                        if (bc.scale && y <= 2*P*Exp_msk1) {
                                 if (aadj <= 0x7fffffff) {
                                         if ((z = aadj) <= 0)
                                                 z = 1;
                                         aadj = z;
-                                        aadj1 = dsign ? aadj : -aadj;
+                                        aadj1 = bc.dsign ? aadj : -aadj;
                                         }
-                                word0(aadj1) += (2*P+1)*Exp_msk1 - y;
+                                dval(&aadj2) = aadj1;
+                                word0(&aadj2) += (2*P+1)*Exp_msk1 - y;
+                                aadj1 = dval(&aadj2);
                                 }
-                        adj = aadj1 * ulp(dval(rv));
-                        dval(rv) += adj;
+                        adj.d = aadj1 * ulp(&rv);
+                        dval(&rv) += adj.d;
 #else
 #ifdef Sudden_Underflow
-                        if ((word0(rv) & Exp_mask) <= P*Exp_msk1) {
-                                dval(rv0) = dval(rv);
-                                word0(rv) += P*Exp_msk1;
-                                adj = aadj1 * ulp(dval(rv));
-                                dval(rv) += adj;
+                        if ((word0(&rv) & Exp_mask) <= P*Exp_msk1) {
+                                dval(&rv0) = dval(&rv);
+                                word0(&rv) += P*Exp_msk1;
+                                adj.d = aadj1 * ulp(&rv);
+                                dval(&rv) += adj.d;
 #ifdef IBM
-                                if ((word0(rv) & Exp_mask) <  P*Exp_msk1)
+                                if ((word0(&rv) & Exp_mask) <  P*Exp_msk1)
 #else
-                                if ((word0(rv) & Exp_mask) <= P*Exp_msk1)
+                                if ((word0(&rv) & Exp_mask) <= P*Exp_msk1)
 #endif
                                         {
-                                        if (word0(rv0) == Tiny0
-                                         && word1(rv0) == Tiny1)
+                                        if (word0(&rv0) == Tiny0
+                                         && word1(&rv0) == Tiny1) {
+                                                if (bc.nd >nd) {
+                                                        bc.uflchk = 1;
+                                                        break;
+                                                        }
                                                 goto undfl;
-                                        word0(rv) = Tiny0;
-                                        word1(rv) = Tiny1;
+                                                }
+                                        word0(&rv) = Tiny0;
+                                        word1(&rv) = Tiny1;
                                         goto cont;
                                         }
                                 else
-                                        word0(rv) -= P*Exp_msk1;
+                                        word0(&rv) -= P*Exp_msk1;
                                 }
                         else {
-                                adj = aadj1 * ulp(dval(rv));
-                                dval(rv) += adj;
+                                adj.d = aadj1 * ulp(&rv);
+                                dval(&rv) += adj.d;
                                 }
 #else /*Sudden_Underflow*/
                         /* Compute adj so that the IEEE rounding rules will
                          * correctly round rv + adj in some half-way cases.
                          * If rv * ulp(rv) is denormalized (i.e.,
                          * y <= (P-1)*Exp_msk1), we must adjust aadj to avoid
                          * trouble from bits lost to denormalization;
                          * example: 1.2e-307 .
                          */
                         if (y <= (P-1)*Exp_msk1 && aadj > 1.) {
                                 aadj1 = (double)(int)(aadj + 0.5);
-                                if (!dsign)
+                                if (!bc.dsign)
                                         aadj1 = -aadj1;
                                 }
-                        adj = aadj1 * ulp(dval(rv));
-                        dval(rv) += adj;
+                        adj.d = aadj1 * ulp(&rv);
+                        dval(&rv) += adj.d;
 #endif /*Sudden_Underflow*/
 #endif /*Avoid_Underflow*/
                         }
-                z = word0(rv) & Exp_mask;
+                z = word0(&rv) & Exp_mask;
 #ifndef SET_INEXACT
+                if (bc.nd == nd) {
 #ifdef Avoid_Underflow
-                if (!scale)
+                if (!bc.scale)
 #endif
                 if (y == z) {
                         /* Can we stop now? */
                         L = (Long)aadj;
                         aadj -= L;
                         /* The tolerances below are conservative. */
-                        if (dsign || word1(rv) || word0(rv) & Bndry_mask) {
+                        if (bc.dsign || word1(&rv) || word0(&rv) & Bndry_mask) {
                                 if (aadj < .4999999 || aadj > .5000001)
                                         break;
                                 }
                         else if (aadj < .4999999/FLT_RADIX)
                                 break;
                         }
+                }
 #endif
  cont:
                 Bfree(bb);
                 Bfree(bd);
                 Bfree(bs);
                 Bfree(delta);
                 }
+        Bfree(bb);
+        Bfree(bd);
+        Bfree(bs);
+        Bfree(bd0);
+        Bfree(delta);
+#ifndef NO_STRTOD_BIGCOMP
+        if (bc.nd > nd)
+                bigcomp(&rv, s0, &bc);
+#endif
 #ifdef SET_INEXACT
-        if (inexact) {
+        if (bc.inexact) {
                 if (!oldinexact) {
-                        word0(rv0) = Exp_1 + (70 << Exp_shift);
-                        word1(rv0) = 0;
-                        dval(rv0) += 1.;
+                        word0(&rv0) = Exp_1 + (70 << Exp_shift);
+                        word1(&rv0) = 0;
+                        dval(&rv0) += 1.;
                         }
                 }
         else if (!oldinexact)
                 clear_inexact();
 #endif
 #ifdef Avoid_Underflow
-        if (scale) {
-                word0(rv0) = Exp_1 - 2*P*Exp_msk1;
-                word1(rv0) = 0;
-                dval(rv) *= dval(rv0);
+        if (bc.scale) {
+                word0(&rv0) = Exp_1 - 2*P*Exp_msk1;
+                word1(&rv0) = 0;
+                dval(&rv) *= dval(&rv0);
 #ifndef NO_ERRNO
                 /* try to avoid the bug of testing an 8087 register value */
 #ifdef IEEE_Arith
-                if (!(word0(rv) & Exp_mask))
+                if (!(word0(&rv) & Exp_mask))
 #else
-                if (word0(rv) == 0 && word1(rv) == 0)
+                if (word0(&rv) == 0 && word1(&rv) == 0)
 #endif
                         errno = ERANGE;
 #endif
                 }
 #endif /* Avoid_Underflow */
 #ifdef SET_INEXACT
-        if (inexact && !(word0(rv) & Exp_mask)) {
+        if (bc.inexact && !(word0(&rv) & Exp_mask)) {
                 /* set underflow bit */
-                dval(rv0) = 1e-300;
-                dval(rv0) *= dval(rv0);
+                dval(&rv0) = 1e-300;
+                dval(&rv0) *= dval(&rv0);
                 }
 #endif
- retfree:
-        Bfree(bb);
-        Bfree(bd);
-        Bfree(bs);
-        Bfree(bd0);
-        Bfree(delta);
  ret:
         if (se)
                 *se = (char *)s;
-        return sign ? -dval(rv) : dval(rv);
-        }
-
- static int
-quorem
-#ifdef KR_headers
-        (b, S) Bigint *b, *S;
-#else
-        (Bigint *b, Bigint *S)
-#endif
-{
-        int n;
-        ULong *bx, *bxe, q, *sx, *sxe;
-#ifdef ULLong
-        ULLong borrow, carry, y, ys;
-#else
-        ULong borrow, carry, y, ys;
-#ifdef Pack_32
-        ULong si, z, zs;
-#endif
-#endif
-
-        n = S->wds;
-#ifdef DEBUG
-        /*debug*/ if (b->wds > n)
-        /*debug*/       Bug("oversize b in quorem");
-#endif
-        if (b->wds < n)
-                return 0;
-        sx = S->x;
-        sxe = sx + --n;
-        bx = b->x;
-        bxe = bx + n;
-        q = *bxe / (*sxe + 1);  /* ensure q <= true quotient */
-#ifdef DEBUG
-        /*debug*/ if (q > 9)
-        /*debug*/       Bug("oversized quotient in quorem");
-#endif
-        if (q) {
-                borrow = 0;
-                carry = 0;
-                do {
-#ifdef ULLong
-                        ys = *sx++ * (ULLong)q + carry;
-                        carry = ys >> 32;
-                        y = *bx - (ys & FFFFFFFF) - borrow;
-                        borrow = y >> 32 & (ULong)1;
-                        *bx++ = y & FFFFFFFF;
-#else
-#ifdef Pack_32
-                        si = *sx++;
-                        ys = (si & 0xffff) * q + carry;
-                        zs = (si >> 16) * q + (ys >> 16);
-                        carry = zs >> 16;
-                        y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
-                        borrow = (y & 0x10000) >> 16;
-                        z = (*bx >> 16) - (zs & 0xffff) - borrow;
-                        borrow = (z & 0x10000) >> 16;
-                        Storeinc(bx, z, y);
-#else
-                        ys = *sx++ * q + carry;
-                        carry = ys >> 16;
-                        y = *bx - (ys & 0xffff) - borrow;
-                        borrow = (y & 0x10000) >> 16;
-                        *bx++ = y & 0xffff;
-#endif
-#endif
-                        }
-                        while(sx <= sxe);
-                if (!*bxe) {
-                        bx = b->x;
-                        while(--bxe > bx && !*bxe)
-                                --n;
-                        b->wds = n;
-                        }
-                }
-        if (cmp(b, S) >= 0) {
-                q++;
-                borrow = 0;
-                carry = 0;
-                bx = b->x;
-                sx = S->x;
-                do {
-#ifdef ULLong
-                        ys = *sx++ + carry;
-                        carry = ys >> 32;
-                        y = *bx - (ys & FFFFFFFF) - borrow;
-                        borrow = y >> 32 & (ULong)1;
-                        *bx++ = y & FFFFFFFF;
-#else
-#ifdef Pack_32
-                        si = *sx++;
-                        ys = (si & 0xffff) + carry;
-                        zs = (si >> 16) + (ys >> 16);
-                        carry = zs >> 16;
-                        y = (*bx & 0xffff) - (ys & 0xffff) - borrow;
-                        borrow = (y & 0x10000) >> 16;
-                        z = (*bx >> 16) - (zs & 0xffff) - borrow;
-                        borrow = (z & 0x10000) >> 16;
-                        Storeinc(bx, z, y);
-#else
-                        ys = *sx++ + carry;
-                        carry = ys >> 16;
-                        y = *bx - (ys & 0xffff) - borrow;
-                        borrow = (y & 0x10000) >> 16;
-                        *bx++ = y & 0xffff;
-#endif
-#endif
-                        }
-                        while(sx <= sxe);
-                bx = b->x;
-                bxe = bx + n;
-                if (!*bxe) {
-                        while(--bxe > bx && !*bxe)
-                                --n;
-                        b->wds = n;
-                        }
-                }
-        return q;
+        return sign ? -dval(&rv) : dval(&rv);
         }
 
 #ifndef MULTIPLE_THREADS
  static char *dtoa_result;
 #endif
 
  static char *
 #ifdef KR_headers
 rv_alloc(i) int i;
 #else
@@ skipping 84 matching lines @@
  *         guarantee that the floating-point calculation has given
  *         the correctly rounded result.  For k requested digits and
  *         "uniformly" distributed input, the probability is
  *         something like 10^(k-15) that we must resort to the Long
  *         calculation.
  */
 
  char *
 dtoa
 #ifdef KR_headers
-        (d, mode, ndigits, decpt, sign, rve)
-        double d; int mode, ndigits, *decpt, *sign; char **rve;
+        (dd, mode, ndigits, decpt, sign, rve)
+        double dd; int mode, ndigits, *decpt, *sign; char **rve;
 #else
-        (double d, int mode, int ndigits, int *decpt, int *sign, char **rve)
+        (double dd, int mode, int ndigits, int *decpt, int *sign, char **rve)
 #endif
 {
  /*     Arguments ndigits, decpt, sign are similar to those
         of ecvt and fcvt; trailing zeros are suppressed from
         the returned string.  If not null, *rve is set to point
         to the end of the return value.  If d is +-Infinity or NaN,
         then *decpt is set to 9999.
 
         mode:
                 0 ==> shortest string that yields d when read in
@@ skipping 16 matching lines @@
                         as modes 2 and 3 when FLT_ROUNDS != 1.
                 6-9 ==> Debugging modes similar to mode - 4:  don't try
                         fast floating-point estimate (if applicable).
 
                 Values of mode other than 0-9 are treated as mode 0.
 
                 Sufficient space is allocated to the return value
                 to hold the suppressed trailing zeros.
         */
 
-        int bbits, b2, b5, be, dig, i, ieps, ilim = 0, ilim0, ilim1 = 0,
+        int bbits, b2, b5, be, dig, i, ieps, ilim, ilim0, ilim1,
                 j, j1, k, k0, k_check, leftright, m2, m5, s2, s5,
                 spec_case, try_quick;
         Long L;
 #ifndef Sudden_Underflow
         int denorm;
         ULong x;
 #endif
         Bigint *b, *b1, *delta, *mlo, *mhi, *S;
-        double d2, ds, eps;
+        U d2, eps, u;
+        double ds;
         char *s, *s0;
 #ifdef SET_INEXACT
         int inexact, oldinexact;
 #endif
 #ifdef Honor_FLT_ROUNDS /*{*/
         int Rounding;
 #ifdef Trust_FLT_ROUNDS /*{{ only define this if FLT_ROUNDS really works! */
         Rounding = Flt_Rounds;
 #else /*}{*/
         Rounding = 1;
         switch(fegetround()) {
           case FE_TOWARDZERO:   Rounding = 0; break;
           case FE_UPWARD:       Rounding = 2; break;
           case FE_DOWNWARD:     Rounding = 3;
           }
 #endif /*}}*/
 #endif /*}*/
 
 #ifndef MULTIPLE_THREADS
         if (dtoa_result) {
                 freedtoa(dtoa_result);
                 dtoa_result = 0;
                 }
 #endif
 
-        if (word0(d) & Sign_bit) {
+        u.d = dd;
+        if (word0(&u) & Sign_bit) {
                 /* set sign for everything, including 0's and NaNs */
                 *sign = 1;
-                word0(d) &= ~Sign_bit;  /* clear sign bit */
+                word0(&u) &= ~Sign_bit; /* clear sign bit */
                 }
         else
                 *sign = 0;
 
 #if defined(IEEE_Arith) + defined(VAX)
 #ifdef IEEE_Arith
-        if ((word0(d) & Exp_mask) == Exp_mask)
+        if ((word0(&u) & Exp_mask) == Exp_mask)
 #else
-        if (word0(d)  == 0x8000)
+        if (word0(&u)  == 0x8000)
 #endif
                 {
                 /* Infinity or NaN */
                 *decpt = 9999;
 #ifdef IEEE_Arith
-                if (!word1(d) && !(word0(d) & 0xfffff))
+                if (!word1(&u) && !(word0(&u) & 0xfffff))
                         return nrv_alloc("Infinity", rve, 8);
 #endif
                 return nrv_alloc("NaN", rve, 3);
                 }
 #endif
 #ifdef IBM
-        dval(d) += 0; /* normalize */
+        dval(&u) += 0; /* normalize */
 #endif
-        if (!dval(d)) {
+        if (!dval(&u)) {
                 *decpt = 1;
                 return nrv_alloc("0", rve, 1);
                 }
 
 #ifdef SET_INEXACT
         try_quick = oldinexact = get_inexact();
         inexact = 1;
 #endif
 #ifdef Honor_FLT_ROUNDS
         if (Rounding >= 2) {
                 if (*sign)
                         Rounding = Rounding == 2 ? 0 : 2;
                 else
                         if (Rounding != 2)
                                 Rounding = 0;
                 }
 #endif
 
-        b = d2b(dval(d), &be, &bbits);
+        b = d2b(&u, &be, &bbits);
 #ifdef Sudden_Underflow
-        i = (int)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1));
+        i = (int)(word0(&u) >> Exp_shift1 & (Exp_mask>>Exp_shift1));
 #else
-        if ((i = (int)(word0(d) >> Exp_shift1 & (Exp_mask>>Exp_shift1)))) {
+        if ((i = (int)(word0(&u) >> Exp_shift1 & (Exp_mask>>Exp_shift1)))) {
 #endif
-                dval(d2) = dval(d);
-                word0(d2) &= Frac_mask1;
-                word0(d2) |= Exp_11;
+                dval(&d2) = dval(&u);
+                word0(&d2) &= Frac_mask1;
+                word0(&d2) |= Exp_11;
 #ifdef IBM
-                if (j = 11 - hi0bits(word0(d2) & Frac_mask))
-                        dval(d2) /= 1 << j;
+                if (j = 11 - hi0bits(word0(&d2) & Frac_mask))
+                        dval(&d2) /= 1 << j;
 #endif
 
                 /* log(x)       ~=~ log(1.5) + (x-1.5)/1.5
                  * log10(x)      =  log(x) / log(10)
                  *              ~=~ log(1.5)/log(10) + (x-1.5)/(1.5*log(10))
                  * log10(d) = (i-Bias)*log(2)/log(10) + log10(d2)
                  *
                  * This suggests computing an approximation k to log10(d) by
                  *
                  * k = (i - Bias)*0.301029995663981
@@ skipping 16 matching lines @@
                 i <<= 2;
                 i += j;
 #endif
 #ifndef Sudden_Underflow
                 denorm = 0;
                 }
         else {
                 /* d is denormalized */
 
                 i = bbits + be + (Bias + (P-1) - 1);
-                x = i > 32  ? word0(d) << 64 - i | word1(d) >> i - 32
-                            : word1(d) << 32 - i;
-                dval(d2) = x;
-                word0(d2) -= 31*Exp_msk1; /* adjust exponent */
+                x = i > 32  ? word0(&u) << (64 - i) | word1(&u) >> (i - 32)
+                            : word1(&u) << (32 - i);
+                dval(&d2) = x;
+                word0(&d2) -= 31*Exp_msk1; /* adjust exponent */
                 i -= (Bias + (P-1) - 1) + 1;
                 denorm = 1;
                 }
 #endif
-        ds = (dval(d2)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981;
+        ds = (dval(&d2)-1.5)*0.289529654602168 + 0.1760912590558 + i*0.301029995663981;
         k = (int)ds;
         if (ds < 0. && ds != k)
                 k--;    /* want k = floor(ds) */
         k_check = 1;
         if (k >= 0 && k <= Ten_pmax) {
-                if (dval(d) < tens[k])
+                if (dval(&u) < tens[k])
                         k--;
                 k_check = 0;
                 }
         j = bbits - i - 1;
         if (j >= 0) {
                 b2 = 0;
                 s2 = j;
                 }
         else {
                 b2 = -j;
@@ skipping 18 matching lines @@
 #else
         try_quick = 1;
 #endif
 #endif /*SET_INEXACT*/
 
         if (mode > 5) {
                 mode -= 4;
                 try_quick = 0;
                 }
         leftright = 1;
+        ilim = ilim1 = -1;      /* Values for cases 0 and 1; done here to */
+                                /* silence erroneous "gcc -Wall" warning. */
         switch(mode) {
                 case 0:
                 case 1:
-                        ilim = ilim1 = -1;
                         i = 18;
                         ndigits = 0;
                         break;
                 case 2:
                         leftright = 0;
                         /* no break */
                 case 4:
                         if (ndigits <= 0)
                                 ndigits = 1;
                         ilim = ilim1 = i = ndigits;
@@ skipping 13 matching lines @@
 #ifdef Honor_FLT_ROUNDS
         if (mode > 1 && Rounding != 1)
                 leftright = 0;
 #endif
 
         if (ilim >= 0 && ilim <= Quick_max && try_quick) {
 
                 /* Try to get by with floating-point arithmetic. */
 
                 i = 0;
-                dval(d2) = dval(d);
+                dval(&d2) = dval(&u);
                 k0 = k;
                 ilim0 = ilim;
                 ieps = 2; /* conservative */
                 if (k > 0) {
                         ds = tens[k&0xf];
                         j = k >> 4;
                         if (j & Bletch) {
                                 /* prevent overflows */
                                 j &= Bletch - 1;
-                                dval(d) /= bigtens[n_bigtens-1];
+                                dval(&u) /= bigtens[n_bigtens-1];
                                 ieps++;
                                 }
                         for(; j; j >>= 1, i++)
                                 if (j & 1) {
                                         ieps++;
                                         ds *= bigtens[i];
                                         }
-                        dval(d) /= ds;
+                        dval(&u) /= ds;
                         }
                 else if ((j1 = -k)) {
-                        dval(d) *= tens[j1 & 0xf];
+                        dval(&u) *= tens[j1 & 0xf];
                         for(j = j1 >> 4; j; j >>= 1, i++)
                                 if (j & 1) {
                                         ieps++;
-                                        dval(d) *= bigtens[i];
+                                        dval(&u) *= bigtens[i];
                                         }
                         }
-                if (k_check && dval(d) < 1. && ilim > 0) {
+                if (k_check && dval(&u) < 1. && ilim > 0) {
                         if (ilim1 <= 0)
                                 goto fast_failed;
                         ilim = ilim1;
                         k--;
-                        dval(d) *= 10.;
+                        dval(&u) *= 10.;
                         ieps++;
                         }
-                dval(eps) = ieps*dval(d) + 7.;
-                word0(eps) -= (P-1)*Exp_msk1;
+                dval(&eps) = ieps*dval(&u) + 7.;
+                word0(&eps) -= (P-1)*Exp_msk1;
                 if (ilim == 0) {
                         S = mhi = 0;
-                        dval(d) -= 5.;
-                        if (dval(d) > dval(eps))
+                        dval(&u) -= 5.;
+                        if (dval(&u) > dval(&eps))
                                 goto one_digit;
-                        if (dval(d) < -dval(eps))
+                        if (dval(&u) < -dval(&eps))
                                 goto no_digits;
                         goto fast_failed;
                         }
 #ifndef No_leftright
                 if (leftright) {
                         /* Use Steele & White method of only
                          * generating digits needed.
                          */
-                        dval(eps) = 0.5/tens[ilim-1] - dval(eps);
+                        dval(&eps) = 0.5/tens[ilim-1] - dval(&eps);
                         for(i = 0;;) {
-                                L = dval(d);
-                                dval(d) -= L;
+                                L = dval(&u);
+                                dval(&u) -= L;
                                 *s++ = '0' + (int)L;
-                                if (dval(d) < dval(eps))
+                                if (dval(&u) < dval(&eps))
                                         goto ret1;
-                                if (1. - dval(d) < dval(eps))
+                                if (1. - dval(&u) < dval(&eps))
                                         goto bump_up;
                                 if (++i >= ilim)
                                         break;
-                                dval(eps) *= 10.;
-                                dval(d) *= 10.;
+                                dval(&eps) *= 10.;
+                                dval(&u) *= 10.;
                                 }
                         }
                 else {
 #endif
                         /* Generate ilim digits, then fix them up. */
-                        dval(eps) *= tens[ilim-1];
-                        for(i = 1;; i++, dval(d) *= 10.) {
-                                L = (Long)(dval(d));
-                                if (!(dval(d) -= L))
+                        dval(&eps) *= tens[ilim-1];
+                        for(i = 1;; i++, dval(&u) *= 10.) {
+                                L = (Long)(dval(&u));
+                                if (!(dval(&u) -= L))
                                         ilim = i;
                                 *s++ = '0' + (int)L;
                                 if (i == ilim) {
-                                        if (dval(d) > 0.5 + dval(eps))
+                                        if (dval(&u) > 0.5 + dval(&eps))
                                                 goto bump_up;
-                                        else if (dval(d) < 0.5 - dval(eps)) {
+                                        else if (dval(&u) < 0.5 - dval(&eps)) {
                                                 while(*--s == '0');
                                                 s++;
                                                 goto ret1;
                                                 }
                                         break;
                                         }
                                 }
 #ifndef No_leftright
                         }
 #endif
  fast_failed:
                 s = s0;
-                dval(d) = dval(d2);
+                dval(&u) = dval(&d2);
                 k = k0;
                 ilim = ilim0;
                 }
 
         /* Do we have a "small" integer? */
 
         if (be >= 0 && k <= Int_max) {
                 /* Yes. */
                 ds = tens[k];
                 if (ndigits < 0 && ilim <= 0) {
                         S = mhi = 0;
-                        if (ilim < 0 || dval(d) <= 5*ds)
+                        if (ilim < 0 || dval(&u) <= 5*ds)
                                 goto no_digits;
                         goto one_digit;
                         }
-                for(i = 1;; i++, dval(d) *= 10.) {
-                        L = (Long)(dval(d) / ds);
-                        dval(d) -= L*ds;
+                for(i = 1;; i++, dval(&u) *= 10.) {
+                        L = (Long)(dval(&u) / ds);
+                        dval(&u) -= L*ds;
 #ifdef Check_FLT_ROUNDS
                         /* If FLT_ROUNDS == 2, L will usually be high by 1 */
-                        if (dval(d) < 0) {
+                        if (dval(&u) < 0) {
                                 L--;
-                                dval(d) += ds;
+                                dval(&u) += ds;
                                 }
 #endif
                         *s++ = '0' + (int)L;
-                        if (!dval(d)) {
+                        if (!dval(&u)) {
 #ifdef SET_INEXACT
                                 inexact = 0;
 #endif
                                 break;
                                 }
                         if (i == ilim) {
 #ifdef Honor_FLT_ROUNDS
                                 if (mode > 1)
                                 switch(Rounding) {
                                   case 0: goto ret1;
                                   case 2: goto bump_up;
                                   }
 #endif
-                                dval(d) += dval(d);
-                                if (dval(d) > ds || dval(d) == ds && L & 1) {
+                                dval(&u) += dval(&u);
+                                if (dval(&u) > ds || (dval(&u) == ds && L & 1)) {
  bump_up:
                                         while(*--s == '9')
                                                 if (s == s0) {
                                                         k++;
                                                         *s = '0';
                                                         break;
                                                         }
                                         ++*s++;
                                         }
                                 break;
@@ skipping 44 matching lines @@
                 S = pow5mult(S, s5);
 
         /* Check for special case that d is a normalized power of 2. */
 
         spec_case = 0;
         if ((mode < 2 || leftright)
 #ifdef Honor_FLT_ROUNDS
                         && Rounding == 1
 #endif
                                 ) {
-                if (!word1(d) && !(word0(d) & Bndry_mask)
+                if (!word1(&u) && !(word0(&u) & Bndry_mask)
 #ifndef Sudden_Underflow
-                 && word0(d) & (Exp_mask & ~Exp_msk1)
+                 && word0(&u) & (Exp_mask & ~Exp_msk1)
 #endif
                                 ) {
                         /* The special case */
                         b2 += Log2P;
                         s2 += Log2P;
                         spec_case = 1;
                         }
                 }
 
         /* Arrange for convenient computation of quotients:
          * shift left if necessary so divisor has 4 leading 0 bits.
          *
          * Perhaps we should just compute leading 28 bits of S once
          * and for all and pass them and a shift to quorem, so it
          * can do shifts and ors to compute the numerator for q.
          */
 #ifdef Pack_32
         if ((i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0x1f))
                 i = 32 - i;
+#define iInc 28
 #else
         if (i = ((s5 ? 32 - hi0bits(S->x[S->wds-1]) : 1) + s2) & 0xf)
                 i = 16 - i;
+#define iInc 12
 #endif
-        if (i > 4) {
-                i -= 4;
-                b2 += i;
-                m2 += i;
-                s2 += i;
-                }
-        else if (i < 4) {
-                i += 28;
-                b2 += i;
-                m2 += i;
-                s2 += i;
-                }
+        i = dshift(S, s2);
+        b2 += i;
+        m2 += i;
+        s2 += i;
         if (b2 > 0)
                 b = lshift(b, b2);
         if (s2 > 0)
                 S = lshift(S, s2);
         if (k_check) {
                 if (cmp(b,S) < 0) {
                         k--;
                         b = multadd(b, 10, 0);  /* we botched the k estimate */
                         if (leftright)
                                 mhi = multadd(mhi, 10, 0);
@@ skipping 30 matching lines @@
                 for(i = 1;;i++) {
                         dig = quorem(b,S) + '0';
                         /* Do we yet have the shortest decimal string
                          * that will round to d?
                          */
                         j = cmp(b, mlo);
                         delta = diff(S, mhi);
                         j1 = delta->sign ? 1 : cmp(b, delta);
                         Bfree(delta);
 #ifndef ROUND_BIASED
-                        if (j1 == 0 && mode != 1 && !(word1(d) & 1)
+                        if (j1 == 0 && mode != 1 && !(word1(&u) & 1)
 #ifdef Honor_FLT_ROUNDS
                                 && Rounding >= 1
 #endif
                                                                    ) {
                                 if (dig == '9')
                                         goto round_9_up;
                                 if (j > 0)
                                         dig++;
 #ifdef SET_INEXACT
                                 else if (!b->x[0] && b->wds <= 1)
                                         inexact = 0;
 #endif
                                 *s++ = dig;
                                 goto ret;
                                 }
 #endif
-                        if (j < 0 || j == 0 && mode != 1
+                        if (j < 0 || (j == 0 && mode != 1
 #ifndef ROUND_BIASED
-                                                        && !(word1(d) & 1)
+                                                        && !(word1(&u) & 1)
 #endif
-                                        ) {
+                                        )) {
                                 if (!b->x[0] && b->wds <= 1) {
 #ifdef SET_INEXACT
                                         inexact = 0;
 #endif
                                         goto accept_dig;
                                         }
 #ifdef Honor_FLT_ROUNDS
                                 if (mode > 1)
                                  switch(Rounding) {
                                   case 0: goto accept_dig;
                                   case 2: goto keep_dig;
                                   }
 #endif /*Honor_FLT_ROUNDS*/
                                 if (j1 > 0) {
                                         b = lshift(b, 1);
                                         j1 = cmp(b, S);
-                                        if ((j1 > 0 || j1 == 0 && dig & 1)
+                                        if ((j1 > 0 || (j1 == 0 && dig & 1))
                                         && dig++ == '9')
                                                 goto round_9_up;
                                         }
  accept_dig:
                                 *s++ = dig;
                                 goto ret;
                                 }
                         if (j1 > 0) {
 #ifdef Honor_FLT_ROUNDS
                                 if (!Rounding)
@@ skipping 39 matching lines @@
         /* Round off last digit */
 
 #ifdef Honor_FLT_ROUNDS
         switch(Rounding) {
           case 0: goto trimzeros;
           case 2: goto roundoff;
           }
 #endif
         b = lshift(b, 1);
         j = cmp(b, S);
-        if (j > 0 || j == 0 && dig & 1) {
+        if (j > 0 || (j == 0 && dig & 1)) {
  roundoff:
                 while(*--s == '9')
                         if (s == s0) {
                                 k++;
                                 *s++ = '1';
                                 goto ret;
                                 }
                 ++*s++;
                 }
         else {
 #ifdef Honor_FLT_ROUNDS
  trimzeros:
 #endif
                 while(*--s == '0');
                 s++;
                 }
  ret:
         Bfree(S);
         if (mhi) {
                 if (mlo && mlo != mhi)
                         Bfree(mlo);
                 Bfree(mhi);
                 }
  ret1:
 #ifdef SET_INEXACT
         if (inexact) {
                 if (!oldinexact) {
-                        word0(d) = Exp_1 + (70 << Exp_shift);
-                        word1(d) = 0;
-                        dval(d) += 1.;
+                        word0(&u) = Exp_1 + (70 << Exp_shift);
+                        word1(&u) = 0;
+                        dval(&u) += 1.;
                         }
                 }
         else if (!oldinexact)
                 clear_inexact();
 #endif
         Bfree(b);
         *s = 0;
         *decpt = k + 1;
         if (rve)
                 *rve = s;
         return s0;
         }
 
 }  // namespace dmg_fp