From 5babbcc0fceb0aa66547feb61124ff548929cbfc Mon Sep 17 00:00:00 2001
From: Richard Guenther <rguenther@suse.de>
Date: Sun, 29 Mar 2009 17:54:04 +0000
Subject: [PATCH] tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Properly
propagate addresses of array references.
2009-03-29 Richard Guenther <rguenther@suse.de>
* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Properly
propagate addresses of array references.
* gcc.dg/tree-ssa/forwprop-11.c: New testcase.
From-SVN: r145250
---
gcc/ChangeLog | 5 +++++
gcc/testsuite/ChangeLog | 4 ++++
gcc/testsuite/gcc.dg/tree-ssa/forwprop-11.c | 19 +++++++++++++++++++
gcc/tree-ssa-forwprop.c | 12 +++++++-----
4 files changed, 35 insertions(+), 5 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/forwprop-11.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5f9b9c14a404..4766e21c994c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2009-03-29 Richard Guenther <rguenther@suse.de>
+
+ * tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Properly
+ propagate addresses of array references.
+
2009-03-29 Steven Bosscher <steven@gcc.gnu.org>
* regmove.c (perhaps_ends_bb_p): Remove.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index f264b33f301a..0807892c7439 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-03-29 Richard Guenther <rguenther@suse.de>
+
+ * gcc.dg/tree-ssa/forwprop-11.c: New testcase.
+
2009-03-29 Daniel Kraft <d@domob.eu>
PR fortran/37423
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/forwprop-11.c b/gcc/testsuite/gcc.dg/tree-ssa/forwprop-11.c
new file mode 100644
index 000000000000..eaaa6dd4e240
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/forwprop-11.c
@@ -0,0 +1,19 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-forwprop1" } */
+
+int f(int *p, int n)
+{
+ int (*a)[n] = (int (*)[n])p;
+ int *q = &(*a)[0];
+ return q[1];
+}
+
+int g(int *p, int n)
+{
+ int (*a)[n] = (int (*)[n])p;
+ int *q = &(*a)[2];
+ return q[-1];
+}
+
+/* { dg-final { scan-tree-dump-times "= \\\(\\\*a_..\\\)\\\[1\\\];" 2 "forwprop1" } } */
+/* { dg-final { cleanup-tree-dump "forwprop1" } } */
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index fb29f91bbf19..859d6fe61726 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -828,19 +828,20 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
array_ref = TREE_OPERAND (def_rhs, 0);
if (TREE_CODE (array_ref) != ARRAY_REF
|| TREE_CODE (TREE_TYPE (TREE_OPERAND (array_ref, 0))) != ARRAY_TYPE
- || !integer_zerop (TREE_OPERAND (array_ref, 1)))
+ || TREE_CODE (TREE_OPERAND (array_ref, 1)) != INTEGER_CST)
return false;
rhs2 = gimple_assign_rhs2 (use_stmt);
- /* Try to optimize &x[0] p+ C where C is a multiple of the size
- of the elements in X into &x[C/element size]. */
+ /* Try to optimize &x[C1] p+ C2 where C2 is a multiple of the size
+ of the elements in X into &x[C1 + C2/element size]. */
if (TREE_CODE (rhs2) == INTEGER_CST)
{
tree new_rhs = maybe_fold_stmt_addition (gimple_expr_type (use_stmt),
- array_ref, rhs2);
+ def_rhs, rhs2);
if (new_rhs)
{
- gimple_assign_set_rhs_from_tree (use_stmt_gsi, new_rhs);
+ gimple_assign_set_rhs_from_tree (use_stmt_gsi,
+ unshare_expr (new_rhs));
use_stmt = gsi_stmt (*use_stmt_gsi);
update_stmt (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
@@ -853,6 +854,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
array elements, then the result is converted into the proper
type for the arithmetic. */
if (TREE_CODE (rhs2) == SSA_NAME
+ && integer_zerop (TREE_OPERAND (array_ref, 1))
&& useless_type_conversion_p (TREE_TYPE (name), TREE_TYPE (def_rhs))
/* Avoid problems with IVopts creating PLUS_EXPRs with a
different type than their operands. */
--
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