Do not raise "inexact" from generic ceil (bug 15479).

C99 and C11 allow but do not require ceil, floor, round and trunc to
raise the "inexact" exception for noninteger arguments.  TS 18661-1
requires that this exception not be raised by these functions.  This
aligns them with general IEEE semantics, where "inexact" is only
raised if the final step of rounding the infinite-precision result to
the result type is inexact; for these functions, the
infinite-precision integer result is always representable in the
result type, so "inexact" should never be raised.

The generic implementations of ceil, floor and round functions contain
code to force "inexact" to be raised.  This patch removes it for ceil
functions to align them with TS 18661-1 in this regard.  Note that
some architecture-specific versions may still raise "inexact", so the
tests are not updated and the bug is not yet fixed.

Tested for x86_64, x86 and mips64.

	[BZ #15479]
	* sysdeps/ieee754/dbl-64/s_ceil.c: Do not mention "inexact"
	exception in comment.
	(huge): Remove variable.
	(__ceil): Do not force "inexact" exception.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c: Do not mention
	"inexact" exception in comment.
	(huge): Remove variable.
	(__ceil): Do not force "inexact" exception.
	* sysdeps/ieee754/flt-32/s_ceilf.c (huge): Remove variable.
	(__ceilf): Do not force "inexact" exception.
	* sysdeps/ieee754/ldbl-128/s_ceill.c: Do not mention "inexact"
	exception in comment.
	(huge): Remove variable.
	(__ceill): Do not force "inexact" exception.
This commit is contained in:
Joseph Myers 2016-05-24 17:42:10 +00:00
parent 6901def689
commit ac2cc6f021
5 changed files with 36 additions and 42 deletions

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@ -1,3 +1,21 @@
2016-05-24 Joseph Myers <joseph@codesourcery.com>
[BZ #15479]
* sysdeps/ieee754/dbl-64/s_ceil.c: Do not mention "inexact"
exception in comment.
(huge): Remove variable.
(__ceil): Do not force "inexact" exception.
* sysdeps/ieee754/dbl-64/wordsize-64/s_ceil.c: Do not mention
"inexact" exception in comment.
(huge): Remove variable.
(__ceil): Do not force "inexact" exception.
* sysdeps/ieee754/flt-32/s_ceilf.c (huge): Remove variable.
(__ceilf): Do not force "inexact" exception.
* sysdeps/ieee754/ldbl-128/s_ceill.c: Do not mention "inexact"
exception in comment.
(huge): Remove variable.
(__ceill): Do not force "inexact" exception.
2016-05-24 H.J. Lu <hongjiu.lu@intel.com>
* config.h.in (BIND_NOW): New.

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@ -15,15 +15,11 @@
* Return x rounded toward -inf to integral value
* Method:
* Bit twiddling.
* Exception:
* Inexact flag raised if x not equal to ceil(x).
*/
#include <math.h>
#include <math_private.h>
static const double huge = 1.0e300;
double
__ceil (double x)
{
@ -33,9 +29,8 @@ __ceil (double x)
j0 = ((i0 >> 20) & 0x7ff) - 0x3ff;
if (j0 < 20)
{
if (j0 < 0) /* raise inexact if x != 0 */
if (j0 < 0)
{
math_force_eval (huge + x);
/* return 0*sign(x) if |x|<1 */
if (i0 < 0)
{
@ -51,7 +46,6 @@ __ceil (double x)
i = (0x000fffff) >> j0;
if (((i0 & i) | i1) == 0)
return x; /* x is integral */
math_force_eval (huge + x); /* raise inexact flag */
if (i0 > 0)
i0 += (0x00100000) >> j0;
i0 &= (~i); i1 = 0;
@ -69,7 +63,6 @@ __ceil (double x)
i = ((u_int32_t) (0xffffffff)) >> (j0 - 20);
if ((i1 & i) == 0)
return x; /* x is integral */
math_force_eval (huge + x); /* raise inexact flag */
if (i0 > 0)
{
if (j0 == 20)

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@ -15,15 +15,11 @@
* Return x rounded toward -inf to integral value
* Method:
* Bit twiddling.
* Exception:
* Inexact flag raised if x not equal to ceil(x).
*/
#include <math.h>
#include <math_private.h>
static const double huge = 1.0e300;
double
__ceil(double x)
{
@ -32,14 +28,13 @@ __ceil(double x)
EXTRACT_WORDS64(i0,x);
j0 = ((i0>>52)&0x7ff)-0x3ff;
if(j0<=51) {
if(j0<0) { /* raise inexact if x != 0 */
math_force_eval(huge+x);/* return 0*sign(x) if |x|<1 */
if(j0<0) {
/* return 0*sign(x) if |x|<1 */
if(i0<0) {i0=INT64_C(0x8000000000000000);}
else if(i0!=0) { i0=INT64_C(0x3ff0000000000000);}
} else {
i = INT64_C(0x000fffffffffffff)>>j0;
if((i0&i)==0) return x; /* x is integral */
math_force_eval(huge+x); /* raise inexact flag */
if(i0>0) i0 += UINT64_C(0x0010000000000000)>>j0;
i0 &= (~i);
}

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@ -17,8 +17,6 @@
#include <math_private.h>
static const float huge = 1.0e30;
float
__ceilf(float x)
{
@ -28,14 +26,13 @@ __ceilf(float x)
GET_FLOAT_WORD(i0,x);
j0 = ((i0>>23)&0xff)-0x7f;
if(j0<23) {
if(j0<0) { /* raise inexact if x != 0 */
math_force_eval(huge+x);/* return 0*sign(x) if |x|<1 */
if(j0<0) {
/* return 0*sign(x) if |x|<1 */
if(i0<0) {i0=0x80000000;}
else if(i0!=0) { i0=0x3f800000;}
} else {
i = (0x007fffff)>>j0;
if((i0&i)==0) return x; /* x is integral */
math_force_eval(huge+x); /* raise inexact flag */
if(i0>0) i0 += (0x00800000)>>j0;
i0 &= (~i);
}

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@ -22,15 +22,11 @@ static char rcsid[] = "$NetBSD: $";
* Return x rounded toward -inf to integral value
* Method:
* Bit twiddling.
* Exception:
* Inexact flag raised if x not equal to ceil(x).
*/
#include <math.h>
#include <math_private.h>
static const long double huge = 1.0e4930L;
long double __ceill(long double x)
{
int64_t i0,i1,j0;
@ -38,26 +34,22 @@ long double __ceill(long double x)
GET_LDOUBLE_WORDS64(i0,i1,x);
j0 = ((i0>>48)&0x7fff)-0x3fff;
if(j0<48) {
if(j0<0) { /* raise inexact if x != 0 */
if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
if(j0<0) {
/* return 0*sign(x) if |x|<1 */
if(i0<0) {i0=0x8000000000000000ULL;i1=0;}
else if((i0|i1)!=0) { i0=0x3fff000000000000ULL;i1=0;}
}
} else {
i = (0x0000ffffffffffffULL)>>j0;
if(((i0&i)|i1)==0) return x; /* x is integral */
if(huge+x>0.0) { /* raise inexact flag */
if(i0>0) i0 += (0x0001000000000000LL)>>j0;
i0 &= (~i); i1=0;
}
}
} else if (j0>111) {
if(j0==0x4000) return x+x; /* inf or NaN */
else return x; /* x is integral */
} else {
i = -1ULL>>(j0-48);
if((i1&i)==0) return x; /* x is integral */
if(huge+x>0.0) { /* raise inexact flag */
if(i0>0) {
if(j0==48) i0+=1;
else {
@ -68,7 +60,6 @@ long double __ceill(long double x)
}
i1 &= (~i);
}
}
SET_LDOUBLE_WORDS64(x,i0,i1);
return x;
}