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| author | Joseph Myers <joseph@codesourcery.com> | 2012-03-05 12:22:46 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2012-03-05 12:22:46 +0000 |
| commit | b7cd39e8f8c5cf2844f20eb03f545d19c4c25987 (patch) | |
| tree | 1b6c55bdacf30fe15197282cf5d556fe708266ed /sysdeps/ieee754/dbl-64/e_pow.c | |
| parent | ca811b2256d2e48c7288219e9e11dcbab3000f19 (diff) | |
| download | glibc-b7cd39e8f8c5cf2844f20eb03f545d19c4c25987.tar.gz | |
Fix pow in non-default rounding modes (bug 3976).
Diffstat (limited to 'sysdeps/ieee754/dbl-64/e_pow.c')
| -rw-r--r-- | sysdeps/ieee754/dbl-64/e_pow.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/sysdeps/ieee754/dbl-64/e_pow.c b/sysdeps/ieee754/dbl-64/e_pow.c index 28435fd36d..f668b4b5fc 100644 --- a/sysdeps/ieee754/dbl-64/e_pow.c +++ b/sysdeps/ieee754/dbl-64/e_pow.c @@ -1,7 +1,7 @@ /* * IBM Accurate Mathematical Library * written by International Business Machines Corp. - * Copyright (C) 2001, 2002, 2004, 2011 Free Software Foundation + * Copyright (C) 2001-2012 Free Software Foundation * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by @@ -41,6 +41,7 @@ #include "MathLib.h" #include "upow.tbl" #include "math_private.h" +#include <fenv.h> #ifndef SECTION # define SECTION @@ -84,6 +85,11 @@ __ieee754_pow(double x, double y) { (u.i[HIGH_HALF]==0 && u.i[LOW_HALF]!=0)) && /* 2^-1023< x<= 2^-1023 * 0x1.0000ffffffff */ (v.i[HIGH_HALF]&0x7fffffff) < 0x4ff00000) { /* if y<-1 or y>1 */ + fenv_t env; + double retval; + + libc_feholdexcept_setround (&env, FE_TONEAREST); + z = log1(x,&aa,&error); /* x^y =e^(y log (X)) */ t = y*134217729.0; y1 = t - (t-y); @@ -97,7 +103,10 @@ __ieee754_pow(double x, double y) { a2 = (a-a1)+aa; error = error*ABS(y); t = __exp1(a1,a2,1.9e16*error); /* return -10 or 0 if wasn't computed exactly */ - return (t>0)?t:power1(x,y); + retval = (t>0)?t:power1(x,y); + + libc_feupdateenv (&env); + return retval; } if (x == 0) { |