system/glibc
3
0
Fork 0
Code Issues Projects Releases Wiki Activity

Fix x86_64 -mfpmath=387 float_t, double_t (bug 20787).

Browse Source 
Bug 20787 reports that, while float_t and double_t for 32-bit x86
properly respect -mfpmath=sse, for x86_64 they fail to reflect
-mfpmath=387, which is valid if unusual and results in FLT_EVAL_METHOD
being 2.  This patch fixes the definitions to respect
__FLT_EVAL_METHOD__ in that case, arranging for the test that the
types correspond with FLT_EVAL_METHOD to be run with both -mfpmath=387
and -mfpmath=sse.

Note: this patch will also have the effect of making float_t and
double_t be long double for x86_64 with -mfpmath=sse+387, when
FLT_EVAL_METHOD is -1.  It seems reasonable for x86_64 to be
consistent with 32-bit x86 in this case (and that definition is
conservatively safe, in that it makes the types correspond to the
widest evaluation format that might be used).

Tested for x86-64 and x86.

	[BZ #20787]
	* sysdeps/x86/bits/mathdef.h (float_t): Do not define to float if
	[__x86_64__] when __FLT_EVAL_METHOD__ is nonzero.
	(double_t): Do not define to double if [__x86_64__] when
	__FLT_EVAL_METHOD__ is nonzero.
	* sysdeps/x86/fpu/test-flt-eval-method-387.c: New file.
	* sysdeps/x86/fpu/test-flt-eval-method-sse.c: Likewise.
	* sysdeps/x86/fpu/Makefile [$(subdir) = math] (tests): Add
	test-flt-eval-method-387 and test-flt-eval-method-sse.
	[$(subdir) = math] (CFLAGS-test-flt-eval-method-387.c): New
	variable.
	[$(subdir) = math] (CFLAGS-test-flt-eval-method-sse.c): Likewise.
This commit is contained in:
Joseph Myers 2016-11-23 17:56:31 +00:00
parent c650aa612f
commit 56ede9ed59
5 changed files with 24 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
ChangeLog
View File

@ -1,3 +1,18 @@
2016-11-23 Joseph Myers <joseph@codesourcery.com>
[BZ #20787]
* sysdeps/x86/bits/mathdef.h (float_t): Do not define to float if
[__x86_64__] when __FLT_EVAL_METHOD__ is nonzero.
(double_t): Do not define to double if [__x86_64__] when
__FLT_EVAL_METHOD__ is nonzero.
* sysdeps/x86/fpu/test-flt-eval-method-387.c: New file.
* sysdeps/x86/fpu/test-flt-eval-method-sse.c: Likewise.
* sysdeps/x86/fpu/Makefile [$(subdir) = math] (tests): Add
test-flt-eval-method-387 and test-flt-eval-method-sse.
[$(subdir) = math] (CFLAGS-test-flt-eval-method-387.c): New
variable.
[$(subdir) = math] (CFLAGS-test-flt-eval-method-sse.c): Likewise.
2016-11-23 Chris Metcalf <cmetcalf@mellanox.com>
* scripts/build-many-glibcs.py (Context.add_all_configs): Revert

3
sysdeps/x86/bits/mathdef.h
View File

@ -22,7 +22,8 @@
#if defined __USE_ISOC99 && defined _MATH_H && !defined _MATH_H_MATHDEF
# define _MATH_H_MATHDEF 1
# if defined __x86_64__ || (defined __FLT_EVAL_METHOD__ && __FLT_EVAL_METHOD__ == 0)
# if ((defined __x86_64__ && !defined __FLT_EVAL_METHOD__) \
|| (defined __FLT_EVAL_METHOD__ && __FLT_EVAL_METHOD__ == 0))
/* The x86-64 architecture computes values with the precission of the
used type. Similarly for -m32 -mfpmath=sse. */
typedef float float_t; /* `float' expressions are evaluated as `float'. */

6
sysdeps/x86/fpu/Makefile
View File

@ -1,7 +1,11 @@
ifeq ($(subdir),math)
libm-support += powl_helper
tests += test-fenv-sse test-fenv-clear-sse test-fenv-x87 test-fenv-sse-2
tests += test-fenv-sse test-fenv-clear-sse test-fenv-x87 test-fenv-sse-2 \
test-flt-eval-method-387 test-flt-eval-method-sse
CFLAGS-test-fenv-sse.c += -msse2 -mfpmath=sse
CFLAGS-test-fenv-clear-sse.c += -msse2 -mfpmath=sse
CFLAGS-test-fenv-sse-2.c += -msse2 -mfpmath=sse
CFLAGS-test-flt-eval-method-387.c += -fexcess-precision=standard -mfpmath=387
CFLAGS-test-flt-eval-method-sse.c += -fexcess-precision=standard -msse2 \
-mfpmath=sse
endif

1
sysdeps/x86/fpu/test-flt-eval-method-387.c Normal file
View File

@ -0,0 +1 @@
#include <test-flt-eval-method.c>

1
sysdeps/x86/fpu/test-flt-eval-method-sse.c Normal file
View File

@ -0,0 +1 @@
#include <test-flt-eval-method.c>