From 377f099ab80623a6d0dacfd4447d45042c385b98 Mon Sep 17 00:00:00 2001
From: Richard Guenther <rguenther@suse.de>
Date: Tue, 19 May 2009 11:51:54 +0000
Subject: [PATCH] tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Do not
falsely claim to have propagated into all uses.
2009-05-19 Richard Guenther <rguenther@suse.de>
* tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Do
not falsely claim to have propagated into all uses.
* gcc.c-torture/compile/20090519-1.c: New testcase.
From-SVN: r147702
---
gcc/ChangeLog | 5 +++
gcc/testsuite/ChangeLog | 4 +++
.../gcc.c-torture/compile/20090519-1.c | 11 ++++++
gcc/tree-ssa-forwprop.c | 36 +++++++++++--------
4 files changed, 42 insertions(+), 14 deletions(-)
create mode 100644 gcc/testsuite/gcc.c-torture/compile/20090519-1.c
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 798ea8244030..1b3b0fc213ca 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2009-05-19 Richard Guenther <rguenther@suse.de>
+
+ * tree-ssa-forwprop.c (forward_propagate_addr_expr_1): Do
+ not falsely claim to have propagated into all uses.
+
2009-05-19 Ben Elliston <bje@au.ibm.com>
* doc/invoke.texi (C Dialect Options): Update OpenMP specification
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 34a7a2d0a4a1..44019be7e3fb 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2009-05-19 Richard Guenther <rguenther@suse.de>
+
+ * gcc.c-torture/compile/20090519-1.c: New testcase.
+
2009-05-18 Jason Merrill <jason@redhat.com>
* g++.dg/cpp0x/explicit1.C: New.
diff --git a/gcc/testsuite/gcc.c-torture/compile/20090519-1.c b/gcc/testsuite/gcc.c-torture/compile/20090519-1.c
new file mode 100644
index 000000000000..54add6b2e1a0
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/20090519-1.c
@@ -0,0 +1,11 @@
+typedef struct { int licensed; } __pmPDUInfo;
+void __pmDecodeXtendError (int *);
+void do_handshake(void)
+{
+ __pmPDUInfo *pduinfo;
+ int challenge;
+ __pmDecodeXtendError(&challenge);
+ pduinfo = (__pmPDUInfo *)&challenge;
+ *pduinfo = *pduinfo;
+}
+
diff --git a/gcc/tree-ssa-forwprop.c b/gcc/tree-ssa-forwprop.c
index 31f2ad71640b..4549ae49ffd3 100644
--- a/gcc/tree-ssa-forwprop.c
+++ b/gcc/tree-ssa-forwprop.c
@@ -717,6 +717,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
tree *rhsp, *lhsp;
gimple use_stmt = gsi_stmt (*use_stmt_gsi);
enum tree_code rhs_code;
+ bool res = true;
gcc_assert (TREE_CODE (def_rhs) == ADDR_EXPR);
@@ -764,19 +765,26 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
/* Now see if the LHS node is an INDIRECT_REF using NAME. If so,
propagate the ADDR_EXPR into the use of NAME and fold the result. */
if (TREE_CODE (lhs) == INDIRECT_REF
- && TREE_OPERAND (lhs, 0) == name
- && may_propagate_address_into_dereference (def_rhs, lhs)
- && (lhsp != gimple_assign_lhs_ptr (use_stmt)
- || useless_type_conversion_p (TREE_TYPE (TREE_OPERAND (def_rhs, 0)),
- TREE_TYPE (rhs))))
+ && TREE_OPERAND (lhs, 0) == name)
{
- *lhsp = unshare_expr (TREE_OPERAND (def_rhs, 0));
- fold_stmt_inplace (use_stmt);
- tidy_after_forward_propagate_addr (use_stmt);
+ if (may_propagate_address_into_dereference (def_rhs, lhs)
+ && (lhsp != gimple_assign_lhs_ptr (use_stmt)
+ || useless_type_conversion_p
+ (TREE_TYPE (TREE_OPERAND (def_rhs, 0)), TREE_TYPE (rhs))))
+ {
+ *lhsp = unshare_expr (TREE_OPERAND (def_rhs, 0));
+ fold_stmt_inplace (use_stmt);
+ tidy_after_forward_propagate_addr (use_stmt);
- /* Continue propagating into the RHS if this was not the only use. */
- if (single_use_p)
- return true;
+ /* Continue propagating into the RHS if this was not the only use. */
+ if (single_use_p)
+ return true;
+ }
+ else
+ /* We can have a struct assignment dereferencing our name twice.
+ Note that we didn't propagate into the lhs to not falsely
+ claim we did when propagating into the rhs. */
+ res = false;
}
/* Strip away any outer COMPONENT_REF, ARRAY_REF or ADDR_EXPR
@@ -796,7 +804,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
*rhsp = unshare_expr (TREE_OPERAND (def_rhs, 0));
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
- return true;
+ return res;
}
/* Now see if the RHS node is an INDIRECT_REF using NAME. If so,
@@ -827,7 +835,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
true, GSI_NEW_STMT);
gimple_assign_set_rhs1 (use_stmt, new_rhs);
tidy_after_forward_propagate_addr (use_stmt);
- return true;
+ return res;
}
/* If the defining rhs comes from an indirect reference, then do not
convert into a VIEW_CONVERT_EXPR. */
@@ -841,7 +849,7 @@ forward_propagate_addr_expr_1 (tree name, tree def_rhs,
*rhsp = new_rhs;
fold_stmt_inplace (use_stmt);
tidy_after_forward_propagate_addr (use_stmt);
- return true;
+ return res;
}
}
--
GitLab