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Fix soft-fp fma for -Wuninitialized. 

The soft-fp implementations of fma produce -Wuninitialized warnings
because, in the cases where the result is not a nonzero finite value,
the soft-fp does not set the exponent of the result since the (cooked)
packing will do so, but the compiler does not then see that the
exponent is always set in packing before it's used if it wasn't set
earlier.  This patch uses DIAG_* macros to suppress those warnings.

Tested for mips64.  (In fact this allows the mips64 build to complete
with the -Wno-uninitialized removed from math/Makefile, but more
cleanups are still needed in the ldbl-128ibm code for uninitialized
warnings there.)

	* soft-fp/fmadf4.c: Include <libc-internal.h>.
	(__fma): Ignore uninitialized warnings around packing.
	* soft-fp/fmasf4.c: Include <libc-internal.h>.
	(__fmaf): Ignore uninitialized warnings around packing.
	* soft-fp/fmatf4.c: Include <libc-internal.h>.
	(__fmal): Ignore uninitialized warnings around packing.
This commit is contained in:
Joseph Myers 2015-05-22 20:28:50 +00:00
parent 0c3717e782
commit dc6b5aed1b
4 changed files with 43 additions and 0 deletions
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7
ChangeLog
View File

@ -1,5 +1,12 @@
2015-05-22 Joseph Myers <joseph@codesourcery.com>
* soft-fp/fmadf4.c: Include <libc-internal.h>.
(__fma): Ignore uninitialized warnings around packing.
* soft-fp/fmasf4.c: Include <libc-internal.h>.
(__fmaf): Ignore uninitialized warnings around packing.
* soft-fp/fmatf4.c: Include <libc-internal.h>.
(__fmal): Ignore uninitialized warnings around packing.
* sysdeps/ieee754/ldbl-128/k_tanl.c: Include <libc-internal.h>.
(__kernel_tanl): Ignore uninitialized warnings around use of SIGN.
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c: Include <libc-internal.h>.

12
soft-fp/fmadf4.c
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@ -25,6 +25,7 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <libc-internal.h>
#include <math.h>
#include "soft-fp.h"
#include "double.h"
@ -44,7 +45,18 @@ __fma (double a, double b, double c)
FP_UNPACK_D (B, b);
FP_UNPACK_D (C, c);
FP_FMA_D (R, A, B, C);
/* R_e is not set in cases where it is not used in packing, but the
compiler does not see that it is set in all cases where it is
used, resulting in warnings that it may be used
uninitialized. */
DIAG_PUSH_NEEDS_COMMENT;
#if __GNUC_PREREQ (4, 7)
DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
#else
DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wuninitialized");
#endif
FP_PACK_D (r, R);
DIAG_POP_NEEDS_COMMENT;
FP_HANDLE_EXCEPTIONS;
return r;

12
soft-fp/fmasf4.c
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@ -25,6 +25,7 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <libc-internal.h>
#include <math.h>
#include "soft-fp.h"
#include "single.h"
@ -44,7 +45,18 @@ __fmaf (float a, float b, float c)
FP_UNPACK_S (B, b);
FP_UNPACK_S (C, c);
FP_FMA_S (R, A, B, C);
/* R_e is not set in cases where it is not used in packing, but the
compiler does not see that it is set in all cases where it is
used, resulting in warnings that it may be used
uninitialized. */
DIAG_PUSH_NEEDS_COMMENT;
#if __GNUC_PREREQ (4, 7)
DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
#else
DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wuninitialized");
#endif
FP_PACK_S (r, R);
DIAG_POP_NEEDS_COMMENT;
FP_HANDLE_EXCEPTIONS;
return r;

12
soft-fp/fmatf4.c
View File

@ -25,6 +25,7 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <libc-internal.h>
#include <math.h>
#include "soft-fp.h"
#include "quad.h"
@ -44,7 +45,18 @@ __fmal (long double a, long double b, long double c)
FP_UNPACK_Q (B, b);
FP_UNPACK_Q (C, c);
FP_FMA_Q (R, A, B, C);
/* R_e is not set in cases where it is not used in packing, but the
compiler does not see that it is set in all cases where it is
used, resulting in warnings that it may be used
uninitialized. */
DIAG_PUSH_NEEDS_COMMENT;
#if __GNUC_PREREQ (4, 7)
DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wmaybe-uninitialized");
#else
DIAG_IGNORE_NEEDS_COMMENT (4.9, "-Wuninitialized");
#endif
FP_PACK_Q (r, R);
DIAG_POP_NEEDS_COMMENT;
FP_HANDLE_EXCEPTIONS;
return r;