From: Richard Guenther <rguenther@suse.de>
Date: Tue, 20 Apr 2010 13:08:01 +0000 (+0000)
Subject: re PR tree-optimization/43629 (Struct to register optimization fails)
X-Git-Tag: releases/gcc-4.3.5~89
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=914f42cb388553353d39522c816086f42be33685;p=thirdparty%2Fgcc.git

re PR tree-optimization/43629 (Struct to register optimization fails)

2010-04-20  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/43629
	* tree-ssa-ccp.c (likely_value): Scan for literal constants
	as well.  Reset all_undefined_operands if we have seen a
	constant value.

	* gcc.c-torture/execute/pr43629.c: New testcase.

From-SVN: r158554
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3126b7d086a1..c8d59b35b91c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2010-04-20  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/43629
+	* tree-ssa-ccp.c (likely_value): Scan for literal constants
+	as well.  Reset all_undefined_operands if we have seen a
+	constant value.
+
 2010-04-18  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR tree-optimization/43769
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index e0a2d40effbd..bbbee43d9860 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2010-04-20  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/43629
+	* gcc.c-torture/execute/pr43629.c: New testcase.
+
 2010-04-18  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/rep_clause5.ad[sb]: New test.
diff --git a/gcc/testsuite/gcc.c-torture/execute/pr43629.c b/gcc/testsuite/gcc.c-torture/execute/pr43629.c
new file mode 100644
index 000000000000..10c0196c89bd
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/execute/pr43629.c
@@ -0,0 +1,13 @@
+int flag;
+extern void abort (void);
+int main()
+{
+  int x;
+  if (flag)
+    x = -1;
+  else 
+    x &= 0xff;
+  if (x & ~0xff)
+    abort ();
+  return 0;
+}
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 08a9ae4d2794..41eed535d50e 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -569,6 +569,34 @@ likely_value (tree stmt)
 	has_constant_operand = true;
     }
 
+  if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT)
+    {
+      tree rhs = GIMPLE_STMT_OPERAND (stmt, 1);
+      if (REFERENCE_CLASS_P (rhs))
+	{
+	  if (is_gimple_min_invariant (TREE_OPERAND (rhs, 0)))
+	    has_constant_operand = true;
+	}
+      else if (EXPR_P (rhs))
+	{
+	  unsigned i;
+	  for (i = 0; i < TREE_CODE_LENGTH (TREE_CODE (rhs)); ++i)
+	    if (TREE_OPERAND (rhs, i)
+		&& is_gimple_min_invariant (TREE_OPERAND (rhs, i)))
+	      has_constant_operand = true;
+	}
+    }
+  else if (TREE_CODE (stmt) == CALL_EXPR)
+    {
+      unsigned i;
+      for (i = 0; i < call_expr_nargs (stmt); ++i)
+	if (is_gimple_min_invariant (CALL_EXPR_ARG (stmt, i)))
+	  has_constant_operand = true;
+    }
+
+  if (has_constant_operand)
+    all_undefined_operands = false;
+
   /* If the operation combines operands like COMPLEX_EXPR make sure to
      not mark the result UNDEFINED if only one part of the result is
      undefined.  */