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| author | Ulrich Drepper <drepper@gmail.com> | 2011-10-12 11:27:51 -0400 |
|---|---|---|
| committer | Ulrich Drepper <drepper@gmail.com> | 2011-10-12 11:27:51 -0400 |
| commit | 0ac5ae2335292908f39031b1ea9fe8edce433c0f (patch) | |
| tree | f9d26c8abc0de39d18d4c13e70f6022cdc6b461f /sysdeps/ieee754/flt-32/e_log2f.c | |
| parent | a843a204a3e8a0dd53584dad3668771abaec84ac (diff) | |
| download | glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.gz glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.bz2 glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.zip | |
Optimize libm
libm is now somewhat integrated with gcc's -ffinite-math-only option
and lots of the wrapper functions have been optimized.
Diffstat (limited to 'sysdeps/ieee754/flt-32/e_log2f.c')
| -rw-r--r-- | sysdeps/ieee754/flt-32/e_log2f.c | 26 |
1 files changed, 8 insertions, 18 deletions
diff --git a/sysdeps/ieee754/flt-32/e_log2f.c b/sysdeps/ieee754/flt-32/e_log2f.c index af3c6eadfe..7453214516 100644 --- a/sysdeps/ieee754/flt-32/e_log2f.c +++ b/sysdeps/ieee754/flt-32/e_log2f.c @@ -18,11 +18,7 @@ #include "math.h" #include "math_private.h" -#ifdef __STDC__ static const float -#else -static float -#endif ln2 = 0.69314718055994530942, two25 = 3.355443200e+07, /* 0x4c000000 */ Lg1 = 6.6666668653e-01, /* 3F2AAAAB */ @@ -33,18 +29,10 @@ Lg5 = 1.8183572590e-01, /* 3E3A3325 */ Lg6 = 1.5313838422e-01, /* 3E1CD04F */ Lg7 = 1.4798198640e-01; /* 3E178897 */ -#ifdef __STDC__ static const float zero = 0.0; -#else -static float zero = 0.0; -#endif -#ifdef __STDC__ - float __ieee754_log2f(float x) -#else - float __ieee754_log2f(x) - float x; -#endif +float +__ieee754_log2f(float x) { float hfsq,f,s,z,R,w,t1,t2,dk; int32_t k,ix,i,j; @@ -53,13 +41,14 @@ static float zero = 0.0; k=0; if (ix < 0x00800000) { /* x < 2**-126 */ - if ((ix&0x7fffffff)==0) + if (__builtin_expect((ix&0x7fffffff)==0, 0)) return -two25/(x-x); /* log(+-0)=-inf */ - if (ix<0) return (x-x)/(x-x); /* log(-#) = NaN */ + if (__builtin_expect(ix<0, 0)) + return (x-x)/(x-x); /* log(-#) = NaN */ k -= 25; x *= two25; /* subnormal number, scale up x */ GET_FLOAT_WORD(ix,x); } - if (ix >= 0x7f800000) return x+x; + if (__builtin_expect(ix >= 0x7f800000, 0)) return x+x; k += (ix>>23)-127; ix &= 0x007fffff; i = (ix+(0x95f64<<3))&0x800000; @@ -72,7 +61,7 @@ static float zero = 0.0; R = f*f*((float)0.5-(float)0.33333333333333333*f); return dk-(R-f)/ln2; } - s = f/((float)2.0+f); + s = f/((float)2.0+f); z = s*s; i = ix-(0x6147a<<3); w = z*z; @@ -88,3 +77,4 @@ static float zero = 0.0; return dk-((s*(f-R))-f)/ln2; } } +strong_alias (__ieee754_log2f, __log2f_finite) |