mirror/glibc
2
0
Fork 0
mirror of git://sourceware.org/git/glibc.git synced 2025-02-23 13:09:58 +08:00
Code Issues Packages Projects Releases Wiki Activity

ieee754: provide gcc builtins based generic sqrt functions

Browse Source 
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
This commit is contained in:
Vineet Gupta 2020-05-29 15:21:39 -07:00
parent ba9f6ee9bb
commit 3374868668
4 changed files with 22 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
sysdeps/generic/math-use-builtins.h
View File

@ -60,4 +60,7 @@
# define USE_COPYSIGNF128_BUILTIN 0
#endif
#define USE_SQRT_BUILTIN 0
#define USE_SQRTF_BUILTIN 0
#endif /* math-use-builtins.h */

6
sysdeps/ieee754/dbl-64/e_sqrt.c
View File

@ -41,6 +41,7 @@
#include <math_private.h>
#include <fenv_private.h>
#include <libm-alias-finite.h>
#include <math-use-builtins.h>
/*********************************************************************/
/* An ultimate sqrt routine. Given an IEEE double machine number x */
@ -50,6 +51,10 @@
double
__ieee754_sqrt (double x)
{
#if USE_SQRT_BUILTIN
return __builtin_sqrt (x);
#else
/* Use generic implementation. */
static const double
rt0 = 9.99999999859990725855365213134618E-01,
rt1 = 4.99999999495955425917856814202739E-01,
@ -138,6 +143,7 @@ __ieee754_sqrt (double x)
return (x - x) / (x - x); /* sqrt(-ve)=sNaN */
return 0x1p-256 * __ieee754_sqrt (x * 0x1p512);
}
#endif /* ! USE_SQRT_BUILTIN */
}
#ifndef __ieee754_sqrt
libm_alias_finite (__ieee754_sqrt, __sqrt)

16
sysdeps/ieee754/flt-32/e_sqrtf.c
View File

@ -16,12 +16,15 @@
#include <math.h>
#include <math_private.h>
#include <libm-alias-finite.h>
static const float one = 1.0, tiny=1.0e-30;
#include <math-use-builtins.h>
float
__ieee754_sqrtf(float x)
{
#if USE_SQRTF_BUILTIN
return __builtin_sqrtf (x);
#else
/* Use generic implementation. */
float z;
int32_t sign = (int)0x80000000;
int32_t ix,s,q,m,t,i;
@ -70,10 +73,10 @@ __ieee754_sqrtf(float x)
/* use floating add to find out rounding direction */
if(ix!=0) {
z = one-tiny; /* trigger inexact flag */
if (z>=one) {
z = one+tiny;
if (z>one)
z = 0x1p0 - 0x1.4484cp-100; /* trigger inexact flag. */
if (z >= 0x1p0) {
z = 0x1p0 + 0x1.4484cp-100;
if (z > 0x1p0)
q += 2;
else
q += (q&1);
@ -83,6 +86,7 @@ __ieee754_sqrtf(float x)
ix += (m <<23);
SET_FLOAT_WORD(z,ix);
return z;
#endif /* ! USE_SQRTF_BUILTIN */
}
#ifndef __ieee754_sqrtf
libm_alias_finite (__ieee754_sqrtf, __sqrtf)

3
sysdeps/s390/fpu/math-use-builtins.h
View File

@ -108,4 +108,7 @@
# define USE_COPYSIGNF128_BUILTIN 0
#endif
#define USE_SQRT_BUILTIN 0
#define USE_SQRTF_BUILTIN 0
#endif /* math-use-builtins.h */