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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_log10f.c | |
| parent | a843a204a3e8a0dd53584dad3668771abaec84ac (diff) | |
| download | glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.gz glibc-0ac5ae2335292908f39031b1ea9fe8edce433c0f.tar.xz 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_log10f.c')
| -rw-r--r-- | sysdeps/ieee754/flt-32/e_log10f.c | 42 |
1 files changed, 14 insertions, 28 deletions
diff --git a/sysdeps/ieee754/flt-32/e_log10f.c b/sysdeps/ieee754/flt-32/e_log10f.c index cea3d9156b..72dcea6250 100644 --- a/sysdeps/ieee754/flt-32/e_log10f.c +++ b/sysdeps/ieee754/flt-32/e_log10f.c @@ -13,55 +13,41 @@ * ==================================================== */ -#if defined(LIBM_SCCS) && !defined(lint) -static char rcsid[] = "$NetBSD: e_log10f.c,v 1.5 1995/05/10 20:45:53 jtc Exp $"; -#endif - #include "math.h" #include "math_private.h" -#ifdef __STDC__ static const float -#else -static float -#endif two25 = 3.3554432000e+07, /* 0x4c000000 */ ivln10 = 4.3429449201e-01, /* 0x3ede5bd9 */ log10_2hi = 3.0102920532e-01, /* 0x3e9a2080 */ log10_2lo = 7.9034151668e-07; /* 0x355427db */ -#ifdef __STDC__ static const float zero = 0.0; -#else -static float zero = 0.0; -#endif -#ifdef __STDC__ - float __ieee754_log10f(float x) -#else - float __ieee754_log10f(x) - float x; -#endif +float +__ieee754_log10f(float x) { float y,z; int32_t i,k,hx; GET_FLOAT_WORD(hx,x); - k=0; - if (hx < 0x00800000) { /* x < 2**-126 */ - if ((hx&0x7fffffff)==0) - return -two25/(x-x); /* log(+-0)=-inf */ - if (hx<0) return (x-x)/(x-x); /* log(-#) = NaN */ - k -= 25; x *= two25; /* subnormal number, scale up x */ + k=0; + if (hx < 0x00800000) { /* x < 2**-126 */ + if (__builtin_expect((hx&0x7fffffff)==0, 0)) + return -two25/(x-x); /* log(+-0)=-inf */ + if (__builtin_expect(hx<0, 0)) + return (x-x)/(x-x); /* log(-#) = NaN */ + k -= 25; x *= two25; /* subnormal number, scale up x */ GET_FLOAT_WORD(hx,x); - } - if (hx >= 0x7f800000) return x+x; + } + if (__builtin_expect(hx >= 0x7f800000, 0)) return x+x; k += (hx>>23)-127; i = ((u_int32_t)k&0x80000000)>>31; - hx = (hx&0x007fffff)|((0x7f-i)<<23); - y = (float)(k+i); + hx = (hx&0x007fffff)|((0x7f-i)<<23); + y = (float)(k+i); SET_FLOAT_WORD(x,hx); z = y*log10_2lo + ivln10*__ieee754_logf(x); return z+y*log10_2hi; } +strong_alias (__ieee754_log10f, __log10f_finite) |