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| author | Ulrich Drepper <drepper@gmail.com> | 2011-10-18 09:00:46 -0400 |
|---|---|---|
| committer | Ulrich Drepper <drepper@gmail.com> | 2011-10-18 09:00:46 -0400 |
| commit | d38f1dba009689d78af371cffa091b27e4ebe17d (patch) | |
| tree | da7daa82001d244a4dbc1ce6dc72cf4e8eac45db /sysdeps/ieee754/dbl-64/wordsize-64 | |
| parent | 83c7615c2dc344562f6a1a499a269b114f74c7e5 (diff) | |
| download | glibc-d38f1dba009689d78af371cffa091b27e4ebe17d.tar.gz | |
Start optimizing the use of the fenv interfaces in libm itself
Diffstat (limited to 'sysdeps/ieee754/dbl-64/wordsize-64')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c | 28 |
1 files changed, 10 insertions, 18 deletions
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c index cb49019ddb..861da20b10 100644 --- a/sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c +++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_nearbyint.c @@ -24,22 +24,14 @@ #include "math.h" #include "math_private.h" -#ifdef __STDC__ static const double -#else -static double -#endif TWO52[2]={ 4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */ -4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */ }; -#ifdef __STDC__ - double __nearbyint(double x) -#else - double __nearbyint(x) - double x; -#endif +double +__nearbyint(double x) { fenv_t env; int64_t i0,sx; @@ -47,20 +39,19 @@ TWO52[2]={ EXTRACT_WORDS64(i0,x); sx = (i0>>63)&1; j0 = ((i0>>52)&0x7ff)-0x3ff; - if(j0<52) { + if(__builtin_expect(j0<52, 1)) { if(j0<0) { if((i0&UINT64_C(0x7fffffffffffffff))==0) return x; uint64_t i = i0 & UINT64_C(0xfffffffffffff); i0 &= UINT64_C(0xfffe000000000000); i0 |= (((i|-i) >> 12) & UINT64_C(0x8000000000000)); INSERT_WORDS64(x,i0); - feholdexcept (&env); + libc_feholdexcept (&env); double w = TWO52[sx]+x; double t = w-TWO52[sx]; - fesetenv (&env); - EXTRACT_WORDS64(i0,t); - INSERT_WORDS64(t,(i0&UINT64_C(0x7fffffffffffffff))|(sx<<63)); - return t; + math_opt_barrier(t); + libc_fesetenv (&env); + return copysign(t, x); } else { uint64_t i = UINT64_C(0x000fffffffffffff)>>j0; if((i0&i)==0) return x; /* x is integral */ @@ -73,10 +64,11 @@ TWO52[2]={ else return x; /* x is integral */ } INSERT_WORDS64(x,i0); - feholdexcept (&env); + libc_feholdexcept (&env); double w = TWO52[sx]+x; double t = w-TWO52[sx]; - fesetenv (&env); + math_opt_barrier (t); + libc_fesetenv (&env); return t; } weak_alias (__nearbyint, nearbyint) |