expr.c (store_constructor): Only set RTX_UNCHANGING_P for read-only field if cleared...

	* expr.c (store_constructor): Only set RTX_UNCHANGING_P for
	read-only field if cleared is 0.

	* gcc.dg/20031202-1.c: New test.

From-SVN: r74250

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 7a7bb75f7f295fb418ee9d6bf1c45da560d831cd..565dd9c78bb352688b49d8a4cf52eaa946849d7d 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2003-12-03  Jakub Jelinek  <jakub@redhat.com>
+
+       * expr.c (store_constructor): Only set RTX_UNCHANGING_P for
+       read-only field if cleared is 0.
+
 2003-12-03  Kean Johnston  <jkj@sco.com>
 
        PR 12969

diff --git a/gcc/expr.c b/gcc/expr.c
index d061347a6943244d9b95f3a5733d8a1d559f76ef..a7c8b4f6d2ae684d24f5761eb2605edbc0a3a85c 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -4936,7 +4936,10 @@ store_constructor (exp, target, cleared, size)
                                       highest_pow2_factor (offset));
            }
 
-         if (TREE_READONLY (field))
+         /* If the constructor has been cleared, setting RTX_UNCHANGING_P
+            on the MEM might lead to scheduling the clearing after the
+            store.  */
+         if (TREE_READONLY (field) && !cleared)
            {
              if (GET_CODE (to_rtx) == MEM)
                to_rtx = copy_rtx (to_rtx);

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 3ac6fdfa036b67e25b62a608ab6cffaf15a3776b..b1d871e0b063b51d59bf626a8f414309d7448e26 100644 (file)
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2003-12-03  Jakub Jelinek  <jakub@redhat.com>
+
+       * gcc.dg/20031202-1.c: New test.
+
 2003-12-03  Josef Zlomek  <zlomekj@suse.cz>
 
        Backport from mainline

diff --git a/gcc/testsuite/gcc.dg/20031202-1.c b/gcc/testsuite/gcc.dg/20031202-1.c
new file mode 100644 (file)
index 0000000..8edfb3f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/20031202-1.c
@@ -0,0 +1,44 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+/* { dg-options "-O2 -mcpu=i686" { target i?86-*-* } } */
+
+extern void abort (void);
+extern void exit (int);
+
+struct A { char p[6]; } __attribute__((packed));
+struct B {
+    struct A a;
+    void * const b;
+    struct A const * const c;
+    struct A const *d;
+};
+
+char v;
+
+int __attribute__((noinline))
+foo (struct B *b)
+{
+  int i;
+  for (i = 0; i < 6; ++i)
+    if (b->a.p[i])
+      abort ();
+  if (b->b != &v || b->c || b->d)
+    abort ();
+  return 12;
+}
+
+int __attribute__((noinline))
+bar (void *x)
+{
+  __asm __volatile ("" : "=r" (x) : "0" (x));
+  struct B y = { .b = x, .c = (void *) 0 };
+  return foo (&y) + 1;
+}
+
+int
+main (void)
+{
+  if (bar (&v) != 13)
+    abort ();
+  exit (0);
+}