From a47a831ad82735bd19cfa1d0b441c1bd62b2a29a Mon Sep 17 00:00:00 2001 From: Ulrich Drepper Date: Tue, 10 Jan 2012 20:52:29 -0500 Subject: Optimize ldexp and scalbn --- sysdeps/ieee754/dbl-64/s_scalbn.c | 40 ++++++++++----------------- sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c | 24 ++++++---------- sysdeps/ieee754/flt-32/s_scalbnf.c | 38 +++++++++---------------- sysdeps/ieee754/ldbl-96/s_scalbnl.c | 38 +++++++++---------------- 4 files changed, 48 insertions(+), 92 deletions(-) (limited to 'sysdeps') diff --git a/sysdeps/ieee754/dbl-64/s_scalbn.c b/sysdeps/ieee754/dbl-64/s_scalbn.c index 3dbfe8fef0..1e67dbe5eb 100644 --- a/sysdeps/ieee754/dbl-64/s_scalbn.c +++ b/sysdeps/ieee754/dbl-64/s_scalbn.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 __scalbn (double x, int n) -#else - double __scalbn (x,n) - double x; int n; -#endif +double +__scalbn (double x, 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 (__scalbn, scalbn) #ifdef NO_LONG_DOUBLE diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c b/sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c index 25cf3b1699..7f0e21f646 100644 --- a/sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c +++ b/sysdeps/ieee754/dbl-64/wordsize-64/s_scalbn.c @@ -1,4 +1,3 @@ -/* @(#)s_scalbn.c 5.1 93/09/24 */ /* * ==================================================== * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved. @@ -20,39 +19,32 @@ #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 __scalbn (double x, int n) -#else - double __scalbn (x,n) - double x; int n; -#endif +double +__scalbn (double x, int n) { int64_t ix; int64_t k; EXTRACT_WORDS64(ix,x); k = (ix >> 52) & 0x7ff; /* extract exponent */ - if (k==0) { /* 0 or subnormal x */ + 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 (k==0x7ff) return x+x; /* NaN or Inf */ + if (__builtin_expect(k==0x7ff, 0)) return x+x; /* NaN or Inf */ k = k+n; - if (n> 50000 || k > 0x7fe) + 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 */ {INSERT_WORDS64(x,(ix&UINT64_C(0x800fffffffffffff))|(k<<52)); return x;} if (k <= -54) diff --git a/sysdeps/ieee754/flt-32/s_scalbnf.c b/sysdeps/ieee754/flt-32/s_scalbnf.c index 407cf607c7..3be2925a03 100644 --- a/sysdeps/ieee754/flt-32/s_scalbnf.c +++ b/sysdeps/ieee754/flt-32/s_scalbnf.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 $"; -#endif - #include "math.h" #include "math_private.h" -#ifdef __STDC__ static const float -#else -static float -#endif two25 = 3.355443200e+07, /* 0x4c000000 */ twom25 = 2.9802322388e-08, /* 0x33000000 */ huge = 1.0e+30, tiny = 1.0e-30; -#ifdef __STDC__ - float __scalbnf (float x, int n) -#else - float __scalbnf (x,n) - float x; int n; -#endif +float +__scalbnf (float x, int n) { int32_t k,ix; GET_FLOAT_WORD(ix,x); - k = (ix&0x7f800000)>>23; /* extract exponent */ - if (k==0) { /* 0 or subnormal x */ - if ((ix&0x7fffffff)==0) return x; /* +-0 */ + k = (ix&0x7f800000)>>23; /* extract exponent */ + if (__builtin_expect(k==0, 0)) { /* 0 or subnormal x */ + if ((ix&0x7fffffff)==0) return x; /* +-0 */ x *= two25; GET_FLOAT_WORD(ix,x); k = ((ix&0x7f800000)>>23) - 25; } - if (k==0xff) return x+x; /* NaN or Inf */ - k = k+n; - if (n> 50000 || k > 0xfe) + if (__builtin_expect(k==0xff, 0)) return x+x; /* NaN or Inf */ + k = k+n; + if (__builtin_expect(n> 50000 || k > 0xfe, 0)) return huge*__copysignf(huge,x); /* overflow */ - if (n< -50000) + if (__builtin_expect(n< -50000, 0)) return tiny*__copysignf(tiny,x); /*underflow*/ - if (k > 0) /* normal result */ + if (__builtin_expect(k > 0, 1)) /* normal result */ {SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); return x;} - if (k <= -25) + if (k <= -25) return tiny*__copysignf(tiny,x); /*underflow*/ - k += 25; /* subnormal result */ + k += 25; /* subnormal result */ SET_FLOAT_WORD(x,(ix&0x807fffff)|(k<<23)); - return x*twom25; + return x*twom25; } weak_alias (__scalbnf, scalbnf) diff --git a/sysdeps/ieee754/ldbl-96/s_scalbnl.c b/sysdeps/ieee754/ldbl-96/s_scalbnl.c index 9f441fd1e9..6a41920aca 100644 --- a/sysdeps/ieee754/ldbl-96/s_scalbnl.c +++ b/sysdeps/ieee754/ldbl-96/s_scalbnl.c @@ -14,10 +14,6 @@ * ==================================================== */ -#if defined(LIBM_SCCS) && !defined(lint) -static char rcsid[] = "$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 two64 = 1.8446744073709551616e19L, twom64 = 5.421010862427522170037e-20L, huge = 1.0e+4900L, tiny = 1.0e-4900L; -#ifdef __STDC__ - long double __scalbnl (long double x, int n) -#else - long double __scalbnl (x,n) - long double x; int n; -#endif +long double +__scalbnl (long double x, 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 *= two64; GET_LDOUBLE_EXP(hx,x); k = (hx&0x7fff) - 64; } - 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 <= -64) + if (k <= -64) return tiny*__copysignl(tiny,x); /*underflow*/ - k += 64; /* subnormal result */ + k += 64; /* subnormal result */ SET_LDOUBLE_EXP(x,(es&0x8000)|k); - return x*twom64; + return x*twom64; } weak_alias (__scalbnl, scalbnl) -- cgit 1.4.1