From: Richard Guenther <rguenther@suse.de>
Date: Thu, 1 May 2008 11:15:32 +0000 (+0000)
Subject: re PR middle-end/36093 (__align__ produces incorrect results in certain cases)
X-Git-Tag: prereleases/gcc-4.2.4-rc1~15
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4824acdd9fc6d9e06603b70d82232153efb0f8f3;p=thirdparty%2Fgcc.git

re PR middle-end/36093 (__align__ produces incorrect results in certain cases)

2008-05-01  Richard Guenther  <rguenther@suse.de>

	PR middle-end/36093
	Backport from mainline
	2007-04-12  Richard Guenther  <rguenther@suse.de>

        * gimplify.c (canonicalize_addr_expr): To be consistent with
        gimplify_compound_lval only set operands two and three of
        ARRAY_REFs if they are not gimple_min_invariant.  This makes
        it never at this place.
        * tree-ssa-ccp.c (maybe_fold_offset_to_array_ref): Likewise.

	* gcc.c-torture/execute/pr36093.c: New testcase.

From-SVN: r134849
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0815f0aeb1c7..f0f12a657e7b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,15 @@
+2008-05-01  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/36093
+	Backport from mainline
+	2007-04-12  Richard Guenther  <rguenther@suse.de>
+
+        * gimplify.c (canonicalize_addr_expr): To be consistent with
+        gimplify_compound_lval only set operands two and three of
+        ARRAY_REFs if they are not gimple_min_invariant.  This makes
+        it never at this place.
+        * tree-ssa-ccp.c (maybe_fold_offset_to_array_ref): Likewise.
+
 2008-04-17  Volker Reichelt  <v.reichelt@netcologne.de>
 
 	PR c/35744
diff --git a/gcc/gimplify.c b/gcc/gimplify.c
index 4acaae2936e2..fa2035bc39c9 100644
--- a/gcc/gimplify.c
+++ b/gcc/gimplify.c
@@ -1600,9 +1600,7 @@ canonicalize_addr_expr (tree *expr_p)
   /* All checks succeeded.  Build a new node to merge the cast.  */
   *expr_p = build4 (ARRAY_REF, dctype, obj_expr,
 		    TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
-		    TYPE_MIN_VALUE (TYPE_DOMAIN (datype)),
-		    size_binop (EXACT_DIV_EXPR, TYPE_SIZE_UNIT (dctype),
-				size_int (TYPE_ALIGN_UNIT (dctype))));
+		    NULL_TREE, NULL_TREE);
   *expr_p = build1 (ADDR_EXPR, ctype, *expr_p);
 }
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 372b94b51f6e..fd3820e0ef48 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2008-05-01  Richard Guenther  <rguenther@suse.de>
+
+	PR middle-end/36093
+	* gcc.c-torture/execute/pr36093.c: New testcase.
+
 2008-04-17  Volker Reichelt  <v.reichelt@netcologne.de>
 
 	PR c/35744
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr36093.c b/gcc/testsuite/gcc.c-torture/execute/pr36093.c
new file mode 100644
index 000000000000..9549bc306b96
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr36093.c
@@ -0,0 +1,28 @@
+extern void abort (void);
+
+typedef struct Bar {
+      char c[129];
+} Bar __attribute__((__aligned__(128)));
+
+typedef struct Foo {
+      Bar bar[4];
+} Foo;
+
+Foo foo[4];
+
+int main()
+{
+   int i, j;
+   Foo *foop = &foo[0];
+
+   for (i=0; i < 4; i++) {
+      Bar *bar = &foop->bar[i];
+      for (j=0; j < 129; j++) {
+         bar->c[j] = 'a' + i;
+      }
+   }
+
+   if (foo[0].bar[3].c[128] != 'd')
+     abort ();
+   return 0;
+}
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index f485b02e4cf2..162191b87751 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -1620,9 +1620,7 @@ maybe_fold_offset_to_array_ref (tree base, tree offset, tree orig_type)
   if (!integer_zerop (elt_offset))
     idx = int_const_binop (PLUS_EXPR, idx, elt_offset, 0);
 
-  return build4 (ARRAY_REF, orig_type, base, idx, min_idx,
-		 size_int (tree_low_cst (elt_size, 1)
-			   / (TYPE_ALIGN_UNIT (elt_type))));
+  return build4 (ARRAY_REF, orig_type, base, idx, NULL_TREE, NULL_TREE);
 }