Updating Opus to a pre-release of 1.1

celt/mathops.h

 /* Copyright (c) 2002-2008 Jean-Marc Valin
    Copyright (c) 2007-2008 CSIRO
    Copyright (c) 2007-2009 Xiph.Org Foundation
    Written by Jean-Marc Valin */
 /**
    @file mathops.h
    @brief Various math functions
 */
 /*
    Redistribution and use in source and binary forms, with or without
@@ skipping 25 matching lines @@
 
 #include "arch.h"
 #include "entcode.h"
 #include "os_support.h"
 
 /* Multiplies two 16-bit fractional values. Bit-exactness of this macro is important */
 #define FRAC_MUL16(a,b) ((16384+((opus_int32)(opus_int16)(a)*(opus_int16)(b)))>>15)
 
 unsigned isqrt32(opus_uint32 _val);
 
+#ifndef OVERRIDE_CELT_MAXABS16
+static inline opus_val32 celt_maxabs16(const opus_val16 *x, int len)
+{
+   int i;
+   opus_val16 maxval = 0;
+   opus_val16 minval = 0;
+   for (i=0;i<len;i++)
+   {
+      maxval = MAX16(maxval, x[i]);
+      minval = MIN16(minval, x[i]);
+   }
+   return MAX32(EXTEND32(maxval),-EXTEND32(minval));
+}
+#endif
+
+#ifndef OVERRIDE_CELT_MAXABS32
+#ifdef FIXED_POINT
+static inline opus_val32 celt_maxabs32(const opus_val32 *x, int len)
+{
+   int i;
+   opus_val32 maxval = 0;
+   opus_val32 minval = 0;
+   for (i=0;i<len;i++)
+   {
+      maxval = MAX32(maxval, x[i]);
+      minval = MIN32(minval, x[i]);
+   }
+   return MAX32(maxval, -minval);
+}
+#else
+#define celt_maxabs32(x,len) celt_maxabs16(x,len)
+#endif
+#endif
+
+
 #ifndef FIXED_POINT
 
 #define PI 3.141592653f
 #define celt_sqrt(x) ((float)sqrt(x))
 #define celt_rsqrt(x) (1.f/celt_sqrt(x))
 #define celt_rsqrt_norm(x) (celt_rsqrt(x))
 #define celt_cos_norm(x) ((float)cos((.5f*PI)*(x)))
 #define celt_rcp(x) (1.f/(x))
 #define celt_div(a,b) ((a)/(b))
 #define frac_div32(a,b) ((float)(a)/(b))
@@ skipping 54 matching lines @@
 
 #ifndef OVERRIDE_CELT_ILOG2
 /** Integer log in base2. Undefined for zero and negative numbers */
 static inline opus_int16 celt_ilog2(opus_int32 x)
 {
    celt_assert2(x>0, "celt_ilog2() only defined for strictly positive numbers");
    return EC_ILOG(x)-1;
 }
 #endif
 
-#ifndef OVERRIDE_CELT_MAXABS16
-static inline opus_val16 celt_maxabs16(opus_val16 *x, int len)
-{
-   int i;
-   opus_val16 maxval = 0;
-   for (i=0;i<len;i++)
-      maxval = MAX16(maxval, ABS16(x[i]));
-   return maxval;
-}
-#endif
-
-#ifndef OVERRIDE_CELT_MAXABS32
-static inline opus_val32 celt_maxabs32(opus_val32 *x, int len)
-{
-   int i;
-   opus_val32 maxval = 0;
-   for (i=0;i<len;i++)
-      maxval = MAX32(maxval, ABS32(x[i]));
-   return maxval;
-}
-#endif
 
 /** Integer log in base2. Defined for zero, but not for negative numbers */
 static inline opus_int16 celt_zlog2(opus_val32 x)
 {
    return x <= 0 ? 0 : celt_ilog2(x);
 }
 
 opus_val16 celt_rsqrt_norm(opus_val32 x);
 
 opus_val32 celt_sqrt(opus_val32 x);
 
 opus_val16 celt_cos_norm(opus_val32 x);
 
+/** Base-2 logarithm approximation (log2(x)). (Q14 input, Q10 output) */
 static inline opus_val16 celt_log2(opus_val32 x)
 {
    int i;
    opus_val16 n, frac;
    /* -0.41509302963303146, 0.9609890551383969, -0.31836011537636605,
        0.15530808010959576, -0.08556153059057618 */
    static const opus_val16 C[5] = {-6801+(1<<(13-DB_SHIFT)), 15746, -5217, 2545, -1401};
    if (x==0)
       return -32767;
    i = celt_ilog2(x);
    n = VSHR32(x,i-15)-32768-16384;
    frac = ADD16(C[0], MULT16_16_Q15(n, ADD16(C[1], MULT16_16_Q15(n, ADD16(C[2], MULT16_16_Q15(n, ADD16(C[3], MULT16_16_Q15(n, C[4]))))))));
    return SHL16(i-13,DB_SHIFT)+SHR16(frac,14-DB_SHIFT);
 }
 
 /*
  K0 = 1
  K1 = log(2)
  K2 = 3-4*log(2)
  K3 = 3*log(2) - 2
 */
 #define D0 16383
 #define D1 22804
 #define D2 14819
 #define D3 10204
+
+static inline opus_val32 celt_exp2_frac(opus_val16 x)
+{
+   opus_val16 frac;
+   frac = SHL16(x, 4);
+   return ADD16(D0, MULT16_16_Q15(frac, ADD16(D1, MULT16_16_Q15(frac, ADD16(D2 , MULT16_16_Q15(D3,frac))))));
+}
 /** Base-2 exponential approximation (2^x). (Q10 input, Q16 output) */
 static inline opus_val32 celt_exp2(opus_val16 x)
 {
    int integer;
    opus_val16 frac;
    integer = SHR16(x,10);
    if (integer>14)
       return 0x7f000000;
    else if (integer < -15)
       return 0;
-   frac = SHL16(x-SHL16(integer,10),4);
-   frac = ADD16(D0, MULT16_16_Q15(frac, ADD16(D1, MULT16_16_Q15(frac, ADD16(D2 , MULT16_16_Q15(D3,frac))))));
+   frac = celt_exp2_frac(x-SHL16(integer,10));
    return VSHR32(EXTEND32(frac), -integer-2);
 }
 
 opus_val32 celt_rcp(opus_val32 x);
 
 #define celt_div(a,b) MULT32_32_Q31((opus_val32)(a),celt_rcp(b))
 
 opus_val32 frac_div32(opus_val32 a, opus_val32 b);
 
 #define M1 32767
@@ skipping 27 matching lines @@
       opus_val32 arg;
       arg = celt_div(SHL32(EXTEND32(x),15),y);
       if (arg >= 32767)
          arg = 32767;
       return 25736-SHR16(celt_atan01(EXTRACT16(arg)),1);
    }
 }
 
 #endif /* FIXED_POINT */
 #endif /* MATHOPS_H */