Remove the lambda framework and make -ftree-loop-linear an alias of -floop-interchange.

[pf3gnuchains/gcc-fork.git] / config / tls.m4

diff --git a/config/tls.m4 b/config/tls.m4
index ef7e6d0..4e170c8 100644 (file)
--- 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);])],