From f76968e6d5ab3ca8bd5b64ba0143197c00f59943 Mon Sep 17 00:00:00 2001
From: Richard Guenther <rguenther@suse.de>
Date: Thu, 9 Apr 2009 08:05:43 +0000
Subject: [PATCH] tree-ssa-ccp.c (maybe_fold_stmt_addition): Move non-constant
indices into an array reference if possible.
2009-04-09 Richard Guenther <rguenther@suse.de>
* tree-ssa-ccp.c (maybe_fold_stmt_addition): Move non-constant
indices into an array reference if possible.
* tree-ssa-forwprop.c (tree_ssa_forward_propagate_single_use_vars):
Fold POINTER_PLUS_EXPR statements with invariant address.
* gcc.dg/tree-ssa/ssa-ccp-25.c: New testcase.
* gcc.dg/tree-ssa/ssa-ccp-26.c: Likewise.
From-SVN: r145799
---
gcc/ChangeLog | 7 ++++
gcc/testsuite/ChangeLog | 5 +++
gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-25.c | 14 ++++++++
gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-26.c | 11 ++++++
gcc/tree-ssa-ccp.c | 39 ++++++++++++++++++++--
gcc/tree-ssa-forwprop.c | 9 +++++
6 files changed, 82 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-25.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-26.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 581337c9d392..f9ffe707a9b3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2009-04-09 Richard Guenther <rguenther@suse.de>
+
+ * tree-ssa-ccp.c (maybe_fold_stmt_addition): Move non-constant
+ indices into an array reference if possible.
+ * tree-ssa-forwprop.c (tree_ssa_forward_propagate_single_use_vars):
+ Fold POINTER_PLUS_EXPR statements with invariant address.
+
2009-04-09 Alan Modra <amodra@bigpond.net.au>
PR target/39634
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 27343277a47c..e56170e1cd0c 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2009-04-09 Richard Guenther <rguenther@suse.de>
+
+ * gcc.dg/tree-ssa/ssa-ccp-25.c: New testcase.
+ * gcc.dg/tree-ssa/ssa-ccp-26.c: Likewise.
+
2009-04-09 Joseph Myers <joseph@codesourcery.com>
PR c/39613
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-25.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-25.c
new file mode 100644
index 000000000000..c6e76a2a3fd8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-25.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-ccp1 -fdump-tree-forwprop1" } */
+
+int a[256];
+int foo(int i)
+{
+ int *p = &a[0];
+ return *(p + i);
+}
+
+/* { dg-final { scan-tree-dump "&a\\\[D\\\." "ccp1" } } */
+/* { dg-final { scan-tree-dump "= a\\\[D\\\." "forwprop1" } } */
+/* { dg-final { cleanup-tree-dump "ccp1" } } */
+/* { dg-final { cleanup-tree-dump "forwprop1" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-26.c b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-26.c
new file mode 100644
index 000000000000..542c42939607
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-26.c
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-forwprop1" } */
+
+int a[256];
+int foo(int i)
+{
+ return (a + 1)[i];
+}
+
+/* { dg-final { scan-tree-dump "= a\\\[D\\\." "forwprop1" } } */
+/* { dg-final { cleanup-tree-dump "forwprop1" } } */
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index a67850448a79..226fd3dbb27c 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -2114,14 +2114,47 @@ maybe_fold_stmt_addition (tree res_type, tree op0, tree op1)
tree ptd_type;
tree t;
- /* It had better be a constant. */
- if (TREE_CODE (op1) != INTEGER_CST)
- return NULL_TREE;
/* The first operand should be an ADDR_EXPR. */
if (TREE_CODE (op0) != ADDR_EXPR)
return NULL_TREE;
op0 = TREE_OPERAND (op0, 0);
+ /* It had better be a constant. */
+ if (TREE_CODE (op1) != INTEGER_CST)
+ {
+ /* Or op0 should now be A[0] and the non-constant offset defined
+ via a multiplication by the array element size. */
+ if (TREE_CODE (op0) == ARRAY_REF
+ && integer_zerop (TREE_OPERAND (op0, 1))
+ && TREE_CODE (op1) == SSA_NAME
+ && host_integerp (TYPE_SIZE_UNIT (TREE_TYPE (op0)), 1))
+ {
+ gimple offset_def = SSA_NAME_DEF_STMT (op1);
+ if (!is_gimple_assign (offset_def))
+ return NULL_TREE;
+
+ if (gimple_assign_rhs_code (offset_def) == MULT_EXPR
+ && TREE_CODE (gimple_assign_rhs2 (offset_def)) == INTEGER_CST
+ && tree_int_cst_equal (gimple_assign_rhs2 (offset_def),
+ TYPE_SIZE_UNIT (TREE_TYPE (op0))))
+ return build1 (ADDR_EXPR, res_type,
+ build4 (ARRAY_REF, TREE_TYPE (op0),
+ TREE_OPERAND (op0, 0),
+ gimple_assign_rhs1 (offset_def),
+ TREE_OPERAND (op0, 2),
+ TREE_OPERAND (op0, 3)));
+ else if (integer_onep (TYPE_SIZE_UNIT (TREE_TYPE (op0)))
+ && gimple_assign_rhs_code (offset_def) != MULT_EXPR)
+ return build1 (ADDR_EXPR, res_type,
+ build4 (ARRAY_REF, TREE_TYPE (op0),
+ TREE_OPERAND (op0, 0),
+ op1,
+ TREE_OPERAND (op0, 2),
+ TREE_OPERAND (op0, 3)));
+ }
+ return NULL_TREE;
+ }
+
/* If the first operand is an ARRAY_REF, expand it so that we can fold
the offset into it. */
while (TREE_CODE (op0) == ARRAY_REF)
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index ff6bda0b1de8..f75e0afa73ff 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -1256,6 +1256,15 @@ tree_ssa_forward_propagate_single_use_vars (void)
else
gsi_next (&gsi);
}
+ else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR
+ && is_gimple_min_invariant (rhs))
+ {
+ /* Make sure to fold &a[0] + off_1 here. */
+ fold_stmt_inplace (stmt);
+ update_stmt (stmt);
+ if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR)
+ gsi_next (&gsi);
+ }
else if ((gimple_assign_rhs_code (stmt) == BIT_NOT_EXPR
|| gimple_assign_rhs_code (stmt) == NEGATE_EXPR)
&& TREE_CODE (rhs) == SSA_NAME)
--
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