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| author | iains <iains@138bc75d-0d04-0410-961f-82ee72b054a4> | 2010-06-09 09:27:04 +0000 |
|---|---|---|
| committer | iains <iains@138bc75d-0d04-0410-961f-82ee72b054a4> | 2010-06-09 09:27:04 +0000 |
| commit | 9a2be16418443da095232a5d0988b1c9cb3cc928 (patch) | |
| tree | 307696aa3f195e924bc7c2146bbcf51ca3871cf7 /config/tls.m4 | |
| parent | cc06cae202dd2aba335582acc73433d0de44c716 (diff) | |
| download | ppe42-gcc-9a2be16418443da095232a5d0988b1c9cb3cc928.tar.gz ppe42-gcc-9a2be16418443da095232a5d0988b1c9cb3cc928.zip | |
config:
PR bootstrap/43170
* tls.m4 (GCC_CHECK_TLS): Add volatile qualifier to the test
references. Move the main () test reference ahead of
pthread_create(). Add a comment to explain the requirements
of the test.
libgomp:
PR bootstrap/43170
* configure: Regenerate.
libjava:
PR bootstrap/43170
* configure: Regenerate.
libmudflap:
PR bootstrap/43170
* configure: Regenerate.
libstdc++-v3:
PR bootstrap/43170
* configure: Regenerate.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@160457 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'config/tls.m4')
| -rw-r--r-- | config/tls.m4 | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/config/tls.m4 b/config/tls.m4 index ef7e6d0b555..4e170c8d6ae 100644 --- a/config/tls.m4 +++ b/config/tls.m4 @@ -38,11 +38,16 @@ AC_DEFUN([GCC_CHECK_TLS], [ CFLAGS="$chktls_save_CFLAGS" if test "X$thread_CFLAGS" != Xfailed; then CFLAGS="$thread_CFLAGS $chktls_save_CFLAGS" + dnl Test for an old glibc bug that violated the __thread property. + dnl Use volatile to ensure the compiler won't optimize away pointer + dnl accesses it might otherwise assume to be redundant, or reorder + dnl them and reuse storage, which might lead to them pointing to + dnl the same location. AC_RUN_IFELSE( [AC_LANG_PROGRAM( [#include <pthread.h> __thread int a; - static int *a_in_other_thread; + static int *volatile a_in_other_thread; static void * thread_func (void *arg) { @@ -51,11 +56,11 @@ AC_DEFUN([GCC_CHECK_TLS], [ }], [pthread_t thread; void *thread_retval; - int *a_in_main_thread; + int *volatile a_in_main_thread; + a_in_main_thread = &a; if (pthread_create (&thread, (pthread_attr_t *)0, thread_func, (void *)0)) return 0; - a_in_main_thread = &a; if (pthread_join (thread, &thread_retval)) return 0; return (a_in_other_thread == a_in_main_thread);])], |
