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Fix test-math-vector-sincos.h aliasing [committed]
- From: Joseph Myers <joseph at codesourcery dot com>
- To: <libc-alpha at sourceware dot org>
- Date: Wed, 15 Mar 2017 17:33:21 +0000
- Subject: Fix test-math-vector-sincos.h aliasing [committed]
- Authentication-results: sourceware.org; auth=none
x86_64 libmvec tests have been failing to build lately with GCC
mainline with -Wuninitialized errors, and Markus Trippelsdorf traced
this to an aliasing issue
<https://sourceware.org/ml/libc-alpha/2017-03/msg00169.html>.
This patch fixes the aliasing issue, so that the vectors-of-pointers
are initialized using a union instead of pointer casts. This also
fixes the testsuite build failures with GCC mainline.
Tested for x86_64 (full testsuite with GCC 6; testsuite build with GCC
mainline with build-many-glibcs.py). Committed.
2017-03-15 Joseph Myers <joseph@codesourcery.com>
* sysdeps/x86/fpu/test-math-vector-sincos.h (INIT_VEC_PTRS_LOOP):
Use a union when storing pointers.
(VECTOR_WRAPPER_fFF_2): Do not take address of integer vector and
cast result when passing to INIT_VEC_PTRS_LOOP.
(VECTOR_WRAPPER_fFF_3): Likewise.
(VECTOR_WRAPPER_fFF_4): Likewise.
diff --git a/sysdeps/x86/fpu/test-math-vector-sincos.h b/sysdeps/x86/fpu/test-math-vector-sincos.h
index 5043b32..95282a3 100644
--- a/sysdeps/x86/fpu/test-math-vector-sincos.h
+++ b/sysdeps/x86/fpu/test-math-vector-sincos.h
@@ -17,14 +17,14 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
-#define INIT_VEC_PTRS_LOOP(vec, val, len) \
- do \
- { \
- for (i = 0; i < len; i++) \
- { \
- vec[i] = &val[i]; \
- } \
- } \
+#define INIT_VEC_PTRS_LOOP(vec, val, len) \
+ do \
+ { \
+ union { VEC_INT_TYPE v; __typeof__ ((val)[0]) *a[(len)]; } u; \
+ for (i = 0; i < len; i++) \
+ u.a[i] = &(val)[i]; \
+ (vec) = u.v; \
+ } \
while (0)
/* Wrapper for vector sincos/sincosf compatible with x86_64 and x32 variants
@@ -40,8 +40,8 @@ void scalar_func (FLOAT x, FLOAT * r, FLOAT * r1) \
VEC_TYPE mx; \
VEC_INT_TYPE mr, mr1; \
INIT_VEC_LOOP (mx, x, VEC_LEN); \
- INIT_VEC_PTRS_LOOP (((FLOAT **) &mr), r_loc, VEC_LEN); \
- INIT_VEC_PTRS_LOOP (((FLOAT **) &mr1), r1_loc, VEC_LEN); \
+ INIT_VEC_PTRS_LOOP (mr, r_loc, VEC_LEN); \
+ INIT_VEC_PTRS_LOOP (mr1, r1_loc, VEC_LEN); \
vector_func (mx, mr, mr1); \
TEST_VEC_LOOP (r_loc, VEC_LEN); \
TEST_VEC_LOOP (r1_loc, VEC_LEN); \
@@ -63,8 +63,8 @@ void scalar_func (FLOAT x, FLOAT * r, FLOAT * r1) \
VEC_TYPE mx; \
VEC_INT_TYPE mr, mr1; \
INIT_VEC_LOOP (mx, x, VEC_LEN); \
- INIT_VEC_PTRS_LOOP (((FLOAT **) &mr), r_loc, VEC_LEN/2); \
- INIT_VEC_PTRS_LOOP (((FLOAT **) &mr1), r1_loc, VEC_LEN/2); \
+ INIT_VEC_PTRS_LOOP (mr, r_loc, VEC_LEN/2); \
+ INIT_VEC_PTRS_LOOP (mr1, r1_loc, VEC_LEN/2); \
vector_func (mx, mr, mr, mr1, mr1); \
TEST_VEC_LOOP (r_loc, VEC_LEN/2); \
TEST_VEC_LOOP (r1_loc, VEC_LEN/2); \
@@ -87,8 +87,8 @@ void scalar_func (FLOAT x, FLOAT * r, FLOAT * r1) \
VEC_TYPE mx; \
VEC_INT_TYPE mr, mr1; \
INIT_VEC_LOOP (mx, x, VEC_LEN); \
- INIT_VEC_PTRS_LOOP (((FLOAT **) &mr), r_loc, VEC_LEN/4); \
- INIT_VEC_PTRS_LOOP (((FLOAT **) &mr1), r1_loc, VEC_LEN/4); \
+ INIT_VEC_PTRS_LOOP (mr, r_loc, VEC_LEN/4); \
+ INIT_VEC_PTRS_LOOP (mr1, r1_loc, VEC_LEN/4); \
vector_func (mx, mr, mr, mr, mr, mr1, mr1, mr1, mr1); \
TEST_VEC_LOOP (r_loc, VEC_LEN/4); \
TEST_VEC_LOOP (r1_loc, VEC_LEN/4); \
--
Joseph S. Myers
joseph@codesourcery.com