Index: fusl/src/math/sqrt.c |
diff --git a/fusl/src/math/sqrt.c b/fusl/src/math/sqrt.c |
index b27756738595dc29a8a7f35e7bffa8da64214826..ff184fa7f08787e47cf524d5dbf066c6103d321e 100644 |
--- a/fusl/src/math/sqrt.c |
+++ b/fusl/src/math/sqrt.c |
@@ -80,106 +80,105 @@ |
static const double tiny = 1.0e-300; |
-double sqrt(double x) |
-{ |
- double z; |
- int32_t sign = (int)0x80000000; |
- int32_t ix0,s0,q,m,t,i; |
- uint32_t r,t1,s1,ix1,q1; |
+double sqrt(double x) { |
+ double z; |
+ int32_t sign = (int)0x80000000; |
+ int32_t ix0, s0, q, m, t, i; |
+ uint32_t r, t1, s1, ix1, q1; |
- EXTRACT_WORDS(ix0, ix1, x); |
+ EXTRACT_WORDS(ix0, ix1, x); |
- /* take care of Inf and NaN */ |
- if ((ix0&0x7ff00000) == 0x7ff00000) { |
- return x*x + x; /* sqrt(NaN)=NaN, sqrt(+inf)=+inf, sqrt(-inf)=sNaN */ |
- } |
- /* take care of zero */ |
- if (ix0 <= 0) { |
- if (((ix0&~sign)|ix1) == 0) |
- return x; /* sqrt(+-0) = +-0 */ |
- if (ix0 < 0) |
- return (x-x)/(x-x); /* sqrt(-ve) = sNaN */ |
- } |
- /* normalize x */ |
- m = ix0>>20; |
- if (m == 0) { /* subnormal x */ |
- while (ix0 == 0) { |
- m -= 21; |
- ix0 |= (ix1>>11); |
- ix1 <<= 21; |
- } |
- for (i=0; (ix0&0x00100000) == 0; i++) |
- ix0<<=1; |
- m -= i - 1; |
- ix0 |= ix1>>(32-i); |
- ix1 <<= i; |
- } |
- m -= 1023; /* unbias exponent */ |
- ix0 = (ix0&0x000fffff)|0x00100000; |
- if (m & 1) { /* odd m, double x to make it even */ |
- ix0 += ix0 + ((ix1&sign)>>31); |
- ix1 += ix1; |
- } |
- m >>= 1; /* m = [m/2] */ |
+ /* take care of Inf and NaN */ |
+ if ((ix0 & 0x7ff00000) == 0x7ff00000) { |
+ return x * x + x; /* sqrt(NaN)=NaN, sqrt(+inf)=+inf, sqrt(-inf)=sNaN */ |
+ } |
+ /* take care of zero */ |
+ if (ix0 <= 0) { |
+ if (((ix0 & ~sign) | ix1) == 0) |
+ return x; /* sqrt(+-0) = +-0 */ |
+ if (ix0 < 0) |
+ return (x - x) / (x - x); /* sqrt(-ve) = sNaN */ |
+ } |
+ /* normalize x */ |
+ m = ix0 >> 20; |
+ if (m == 0) { /* subnormal x */ |
+ while (ix0 == 0) { |
+ m -= 21; |
+ ix0 |= (ix1 >> 11); |
+ ix1 <<= 21; |
+ } |
+ for (i = 0; (ix0 & 0x00100000) == 0; i++) |
+ ix0 <<= 1; |
+ m -= i - 1; |
+ ix0 |= ix1 >> (32 - i); |
+ ix1 <<= i; |
+ } |
+ m -= 1023; /* unbias exponent */ |
+ ix0 = (ix0 & 0x000fffff) | 0x00100000; |
+ if (m & 1) { /* odd m, double x to make it even */ |
+ ix0 += ix0 + ((ix1 & sign) >> 31); |
+ ix1 += ix1; |
+ } |
+ m >>= 1; /* m = [m/2] */ |
- /* generate sqrt(x) bit by bit */ |
- ix0 += ix0 + ((ix1&sign)>>31); |
- ix1 += ix1; |
- q = q1 = s0 = s1 = 0; /* [q,q1] = sqrt(x) */ |
- r = 0x00200000; /* r = moving bit from right to left */ |
+ /* generate sqrt(x) bit by bit */ |
+ ix0 += ix0 + ((ix1 & sign) >> 31); |
+ ix1 += ix1; |
+ q = q1 = s0 = s1 = 0; /* [q,q1] = sqrt(x) */ |
+ r = 0x00200000; /* r = moving bit from right to left */ |
- while (r != 0) { |
- t = s0 + r; |
- if (t <= ix0) { |
- s0 = t + r; |
- ix0 -= t; |
- q += r; |
- } |
- ix0 += ix0 + ((ix1&sign)>>31); |
- ix1 += ix1; |
- r >>= 1; |
- } |
+ while (r != 0) { |
+ t = s0 + r; |
+ if (t <= ix0) { |
+ s0 = t + r; |
+ ix0 -= t; |
+ q += r; |
+ } |
+ ix0 += ix0 + ((ix1 & sign) >> 31); |
+ ix1 += ix1; |
+ r >>= 1; |
+ } |
- r = sign; |
- while (r != 0) { |
- t1 = s1 + r; |
- t = s0; |
- if (t < ix0 || (t == ix0 && t1 <= ix1)) { |
- s1 = t1 + r; |
- if ((t1&sign) == sign && (s1&sign) == 0) |
- s0++; |
- ix0 -= t; |
- if (ix1 < t1) |
- ix0--; |
- ix1 -= t1; |
- q1 += r; |
- } |
- ix0 += ix0 + ((ix1&sign)>>31); |
- ix1 += ix1; |
- r >>= 1; |
- } |
+ r = sign; |
+ while (r != 0) { |
+ t1 = s1 + r; |
+ t = s0; |
+ if (t < ix0 || (t == ix0 && t1 <= ix1)) { |
+ s1 = t1 + r; |
+ if ((t1 & sign) == sign && (s1 & sign) == 0) |
+ s0++; |
+ ix0 -= t; |
+ if (ix1 < t1) |
+ ix0--; |
+ ix1 -= t1; |
+ q1 += r; |
+ } |
+ ix0 += ix0 + ((ix1 & sign) >> 31); |
+ ix1 += ix1; |
+ r >>= 1; |
+ } |
- /* use floating add to find out rounding direction */ |
- if ((ix0|ix1) != 0) { |
- z = 1.0 - tiny; /* raise inexact flag */ |
- if (z >= 1.0) { |
- z = 1.0 + tiny; |
- if (q1 == (uint32_t)0xffffffff) { |
- q1 = 0; |
- q++; |
- } else if (z > 1.0) { |
- if (q1 == (uint32_t)0xfffffffe) |
- q++; |
- q1 += 2; |
- } else |
- q1 += q1 & 1; |
- } |
- } |
- ix0 = (q>>1) + 0x3fe00000; |
- ix1 = q1>>1; |
- if (q&1) |
- ix1 |= sign; |
- ix0 += m << 20; |
- INSERT_WORDS(z, ix0, ix1); |
- return z; |
+ /* use floating add to find out rounding direction */ |
+ if ((ix0 | ix1) != 0) { |
+ z = 1.0 - tiny; /* raise inexact flag */ |
+ if (z >= 1.0) { |
+ z = 1.0 + tiny; |
+ if (q1 == (uint32_t)0xffffffff) { |
+ q1 = 0; |
+ q++; |
+ } else if (z > 1.0) { |
+ if (q1 == (uint32_t)0xfffffffe) |
+ q++; |
+ q1 += 2; |
+ } else |
+ q1 += q1 & 1; |
+ } |
+ } |
+ ix0 = (q >> 1) + 0x3fe00000; |
+ ix1 = q1 >> 1; |
+ if (q & 1) |
+ ix1 |= sign; |
+ ix0 += m << 20; |
+ INSERT_WORDS(z, ix0, ix1); |
+ return z; |
} |