From 41d0e8696f370d625390da356d95cab174c7990e Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Wed, 11 Jan 2012 12:49:16 -0500 Subject: [PATCH] Optimize scalbln --- ChangeLog | 9 +++- sysdeps/ieee754/dbl-64/s_scalbln.c | 40 ++++++----------- sysdeps/ieee754/dbl-64/wordsize-64/s_scalbln.c | 60 ++++++++++++++++++++++++++ sysdeps/ieee754/flt-32/s_scalblnf.c | 38 ++++++---------- sysdeps/ieee754/ldbl-96/s_scalblnl.c | 38 ++++++---------- 5 files changed, 108 insertions(+), 77 deletions(-) create mode 100644 sysdeps/ieee754/dbl-64/wordsize-64/s_scalbln.c diff --git a/ChangeLog b/ChangeLog index 9ebbdf9..7b87e2c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,10 @@ +2012-01-11 Ulrich Drepper + + * sysdeps/ieee754/dbl-64/s_scalbln.c: Add branch prediction. + * sysdeps/ieee754/flt-32/s_scalblnf.c: Likewise. + * sysdeps/ieee754/ldbl-96/s_scalblnl.c: Likewise. + * sysdeps/ieee754/dbl-64/wordsize-64/s_scalbln.c: New file. + 2012-01-10 Ulrich Drepper * sysdeps/ieee754/dbl-64/wordsize-64/s_modf.c: New file. @@ -9,9 +16,9 @@ * math/bits/mathcalls.h: Add const attribute to fmin and fmax. * sysdeps/ieee754/dbl-64/s_scalbn.c: Add branch prediction. - * sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c: Likewise. * sysdeps/ieee754/flt-32/s_scalbnf.c: Likewise. * sysdeps/ieee754/ldbl-96/s_scalbnl.c: Likewise. + * sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c: New file. * math/bits/math-finite.h: Add ldexp support. diff --git a/sysdeps/ieee754/dbl-64/s_scalbln.c b/sysdeps/ieee754/dbl-64/s_scalbln.c index aa6134f..89174b4 100644 --- a/sysdeps/ieee754/dbl-64/s_scalbln.c +++ b/sysdeps/ieee754/dbl-64/s_scalbln.c @@ -1,4 +1,3 @@ -/* @(#)s_scalbn.c 5.1 93/09/24 */ /* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. @@ -10,10 +9,6 @@ * ==================================================== */ -#if defined(LIBM_SCCS) && !defined(lint) -static char rcsid[] = "$NetBSD: s_scalbn.c,v 1.8 1995/05/10 20:48:08 jtc Exp $"; -#endif - /* * scalbn (double x, int n) * scalbn(x,n) returns x* 2**n computed by exponent @@ -24,44 +19,37 @@ static char rcsid[] = "$NetBSD: s_scalbn.c,v 1.8 1995/05/10 20:48:08 jtc Exp $"; #include "math.h" #include "math_private.h" -#ifdef __STDC__ static const double -#else -static double -#endif two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */ twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */ huge = 1.0e+300, tiny = 1.0e-300; -#ifdef __STDC__ - double __scalbln (double x, long int n) -#else - double __scalbln (x,n) - double x; long int n; -#endif +double +__scalbln (double x, long int n) { int32_t k,hx,lx; EXTRACT_WORDS(hx,lx,x); - k = (hx&0x7ff00000)>>20; /* extract exponent */ - if (k==0) { /* 0 or subnormal x */ - if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */ + k = (hx&0x7ff00000)>>20; /* extract exponent */ + if (__builtin_expect(k==0, 0)) { /* 0 or subnormal x */ + if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */ x *= two54; GET_HIGH_WORD(hx,x); k = ((hx&0x7ff00000)>>20) - 54; } - if (k==0x7ff) return x+x; /* NaN or Inf */ - k = k+n; - if (n> 50000 || k > 0x7fe) + if (__builtin_expect(k==0x7ff, 0)) return x+x; /* NaN or Inf */ + k = k+n; + if (__builtin_expect(n> 50000 || k > 0x7fe, 0)) return huge*__copysign(huge,x); /* overflow */ - if (n< -50000) return tiny*__copysign(tiny,x); /*underflow*/ - if (k > 0) /* normal result */ + if (__builtin_expect(n< -50000, 0)) + return tiny*__copysign(tiny,x); /*underflow*/ + if (__builtin_expect(k > 0, 1)) /* normal result */ {SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20)); return x;} - if (k <= -54) + if (k <= -54) return tiny*__copysign(tiny,x); /*underflow*/ - k += 54; /* subnormal result */ + k += 54; /* subnormal result */ SET_HIGH_WORD(x,(hx&0x800fffff)|(k<<20)); - return x*twom54; + return x*twom54; } weak_alias (__scalbln, scalbln) #ifdef NO_LONG_DOUBLE diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_scalbln.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_scalbln.c new file mode 100644 index 0000000..d6b97b5 --- /dev/null +++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_scalbln.c @@ -0,0 +1,60 @@ +/* + * ==================================================== + * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. + * + * Developed at SunPro, a Sun Microsystems, Inc. business. + * Permission to use, copy, modify, and distribute this + * software is freely granted, provided that this notice + * is preserved. + * ==================================================== + */ + +/* + * scalbn (double x, int n) + * scalbn(x,n) returns x* 2**n computed by exponent + * manipulation rather than by actually performing an + * exponentiation or a multiplication. + */ + +#include "math.h" +#include "math_private.h" + +static const double +two54 = 1.80143985094819840000e+16, /* 0x43500000, 0x00000000 */ +twom54 = 5.55111512312578270212e-17, /* 0x3C900000, 0x00000000 */ +huge = 1.0e+300, +tiny = 1.0e-300; + +double +__scalbln (double x, long int n) +{ + int64_t ix; + int64_t k; + EXTRACT_WORDS64(ix,x); + k = (ix >> 52) & 0x7ff; /* extract exponent */ + if (__builtin_expect(k==0, 0)) { /* 0 or subnormal x */ + if ((ix & UINT64_C(0xfffffffffffff))==0) return x; /* +-0 */ + x *= two54; + EXTRACT_WORDS64(ix,x); + k = ((ix >> 52) & 0x7ff) - 54; + } + if (__builtin_expect(k==0x7ff, 0)) return x+x; /* NaN or Inf */ + k = k+n; + if (__builtin_expect(n> 50000 || k > 0x7fe, 0)) + return huge*__copysign(huge,x); /* overflow */ + if (__builtin_expect(n< -50000, 0)) + return tiny*__copysign(tiny,x); /*underflow*/ + if (__builtin_expect(k > 0, 1)) /* normal result */ + {INSERT_WORDS64(x,(ix&UINT64_C(0x800fffffffffffff))|(k<<52)); + return x;} + if (k <= -54) + return tiny*__copysign(tiny,x); /*underflow*/ + k += 54; /* subnormal result */ + INSERT_WORDS64(x,(ix&INT64_C(0x800fffffffffffff))|(k<<52)); + return x*twom54; +} +weak_alias (__scalbln, scalbln) +#ifdef NO_LONG_DOUBLE +strong_alias (__scalbln, __scalblnl) +weak_alias (__scalbln, scalblnl) +#endif diff --git a/sysdeps/ieee754/flt-32/s_scalblnf.c b/sysdeps/ieee754/flt-32/s_scalblnf.c index 4ed4873..5256c32 100644 --- a/sysdeps/ieee754/flt-32/s_scalblnf.c +++ b/sysdeps/ieee754/flt-32/s_scalblnf.c @@ -13,51 +13,39 @@ * ==================================================== */ -#if defined(LIBM_SCCS) && !defined(lint) -static char rcsid[] = "$NetBSD: s_scalbnf.c,v 1.4 1995/05/10 20:48:10 jtc Exp $"; -#endif - #include "math.h" #include "math_private.h" -#ifdef __STDC__ static const float -#else -static float -#endif two25 = 3.355443200e+07, /* 0x4c000000 */ twom25 = 2.9802322388e-08, /* 0x33000000 */ huge = 1.0e+30, tiny = 1.0e-30; -#ifdef __STDC__ - float __scalblnf (float x, long int n) -#else - float __scalblnf (x,n) - float x; long int n; -#endif +float +__scalblnf (float x, long int n) { int32_t k,ix; GET_FLOAT_WORD(ix,x); - k = (ix&0x7f800000)>>23; /* extract exponent */ - if (k==0) { /* 0 or subnormal x */ - if ((ix&0x7fffffff)==0) return x; /* +-0 */ + k = (ix&0x7f800000)>>23; /* extract exponent */ + if (__builtin_expect(k==0, 0)) { /* 0 or subnormal x */ + if ((ix&0x7fffffff)==0) return x; /* +-0 */ x *= two25; GET_FLOAT_WORD(ix,x); k = ((ix&0x7f800000)>>23) - 25; } - if (k==0xff) return x+x; /* NaN or Inf */ - k = k+n; - if (n> 50000 || k > 0xfe) + if (__builtin_expect(k==0xff, 0)) return x+x; /* NaN or Inf */ + k = k+n; + if (__builtin_expect(n> 50000 || k > 0xfe, 0)) return huge*copysignf(huge,x); /* overflow */ - if (n< -50000) + if (__builtin_expect(n< -50000, 0)) return tiny*copysignf(tiny,x); /*underflow*/ - if (k > 0) /* normal result */ + if (__builtin_expect(k > 0, 1)) /* normal result */ {SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;} - if (k <= -25) + if (k <= -25) return tiny*copysignf(tiny,x); /*underflow*/ - k += 25; /* subnormal result */ + k += 25; /* subnormal result */ SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); - return x*twom25; + return x*twom25; } weak_alias (__scalblnf, scalblnf) diff --git a/sysdeps/ieee754/ldbl-96/s_scalblnl.c b/sysdeps/ieee754/ldbl-96/s_scalblnl.c index 8e556fa..ada587b 100644 --- a/sysdeps/ieee754/ldbl-96/s_scalblnl.c +++ b/sysdeps/ieee754/ldbl-96/s_scalblnl.c @@ -14,10 +14,6 @@ * ==================================================== */ -#if defined(LIBM_SCCS) && !defined(lint) -static char rcsid[] = "$NetBSD: $"; -#endif - /* * scalbnl (long double x, int n) * scalbnl(x,n) returns x* 2**n computed by exponent @@ -28,44 +24,36 @@ static char rcsid[] = "$NetBSD: $"; #include "math.h" #include "math_private.h" -#ifdef __STDC__ static const long double -#else -static long double -#endif two63 = 4.50359962737049600000e+15, twom63 = 1.08420217248550443400e-19, huge = 1.0e+4900L, tiny = 1.0e-4900L; -#ifdef __STDC__ - long double __scalblnl (long double x, long int n) -#else - long double __scalblnl (x,n) - long double x; long int n; -#endif +long double +__scalblnl (long double x, long int n) { int32_t k,es,hx,lx; GET_LDOUBLE_WORDS(es,hx,lx,x); - k = es&0x7fff; /* extract exponent */ - if (k==0) { /* 0 or subnormal x */ - if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */ + k = es&0x7fff; /* extract exponent */ + if (__builtin_expect(k==0, 0)) { /* 0 or subnormal x */ + if ((lx|(hx&0x7fffffff))==0) return x; /* +-0 */ x *= two63; GET_LDOUBLE_EXP(es,x); k = (hx&0x7fff) - 63; } - if (k==0x7fff) return x+x; /* NaN or Inf */ - k = k+n; - if (n> 50000 || k > 0x7ffe) + if (__builtin_expect(k==0x7fff, 0)) return x+x; /* NaN or Inf */ + k = k+n; + if (__builtin_expect(n> 50000 || k > 0x7ffe, 0)) return huge*__copysignl(huge,x); /* overflow */ - if (n< -50000) + if (__builtin_expect(n< -50000, 0)) return tiny*__copysignl(tiny,x); - if (k > 0) /* normal result */ + if (__builtin_expect(k > 0, 1)) /* normal result */ {SET_LDOUBLE_EXP(x,(es&0x8000)|k); return x;} - if (k <= -63) + if (k <= -63) return tiny*__copysignl(tiny,x); /*underflow*/ - k += 63; /* subnormal result */ + k += 63; /* subnormal result */ SET_LDOUBLE_EXP(x,(es&0x8000)|k); - return x*twom63; + return x*twom63; } weak_alias (__scalblnl, scalblnl) -- 2.7.4