From e3cc72542ba605f704f9590ef6d5b91bd9b66233 Mon Sep 17 00:00:00 2001
From: Zdenek Dvorak <dvorakz@suse.cz>
Date: Wed, 27 Apr 2005 16:28:11 +0200
Subject: [PATCH] re PR tree-optimization/21171 (IV OPTS removes does not
 create a new VOPs for constant values)

	PR tree-optimization/21171
	* tree-ssa-loop-ivopts.c (find_interesting_uses_address): Do not
	record address uses if the reference is volatile.

	* gcc.dg/tree-ssa/pr21171.c: New test.

From-SVN: r98828
---
 gcc/ChangeLog                           |  6 +++++
 gcc/testsuite/ChangeLog                 |  5 +++++
 gcc/testsuite/gcc.dg/tree-ssa/pr21171.c | 29 +++++++++++++++++++++++++
 gcc/tree-ssa-loop-ivopts.c              |  5 +++++
 4 files changed, 45 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr21171.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5a99ffa1aff..2a545fd9a65 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2005-04-27  Zdenek Dvorak  <dvorakz@suse.cz>
+
+	PR tree-optimization/21171
+	* tree-ssa-loop-ivopts.c (find_interesting_uses_address): Do not
+	record address uses if the reference is volatile.
+
 2004-04-27  Paolo Bonzini  <bonzini@gnu.org>
 
 	* tree-complex.c (expand_vector_operation): New, extracted from
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0f69c320f7d..78ac81ac2aa 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2005-04-27  Zdenek Dvorak  <dvorakz@suse.cz>
+
+	PR tree-optimization/21171
+	* gcc.dg/tree-ssa/pr21171.c: New test.
+
 2004-04-27  Paolo Bonzini  <bonzini@gnu.org>
 
         * gcc.dg/tree-ssa/gen-vect-11.c, gcc.dg/tree-ssa/gen-vect-11a.c,
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr21171.c b/gcc/testsuite/gcc.dg/tree-ssa/pr21171.c
new file mode 100644
index 00000000000..a655ed63281
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr21171.c
@@ -0,0 +1,29 @@
+/* PR 21171.  Ivopts should not rewrite references to volatile memory.  */
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-vars" } */
+
+typedef	unsigned int u_int32_t;
+typedef	unsigned char u_int8_t;
+
+#define	AIC_VECTORS	32
+
+typedef volatile struct AT91RM9200_regs {
+  u_int32_t	SVR[AIC_VECTORS];
+} AT91RM9200_regs_t;
+
+#define CPUReg  ((AT91RM9200_regs_t*)0xFFF00000)
+
+extern const u_int32_t __IntTable[AIC_VECTORS];
+
+int main()
+{
+  int c;
+
+  for (c = 0; c < AIC_VECTORS; c++)
+    CPUReg->SVR[c] = __IntTable[c];
+
+  return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "SVR" 1 "vars"} } */
+/* { dg-final { cleanup-tree-dump "vars" } } */
diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index a62c1cda8f4..f23e8d6d3a5 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -1518,6 +1518,11 @@ find_interesting_uses_address (struct ivopts_data *data, tree stmt, tree *op_p)
   struct iv *civ;
   struct ifs_ivopts_data ifs_ivopts_data;
 
+  /* Do not play with volatile memory references.  A bit too conservative,
+     perhaps, but safe.  */
+  if (stmt_ann (stmt)->has_volatile_ops)
+    goto fail;
+
   /* Ignore bitfields for now.  Not really something terribly complicated
      to handle.  TODO.  */
   if (TREE_CODE (base) == COMPONENT_REF