This fixes missed tracking of alignment of non-invariant addresses
in CCP.
Bootstrapped and tested on x86_64-unknown-linux-gnu, queued for GCC 6.
Richard.
2015-02-25 Richard Biener <rguent...@suse.de>
PR tree-optimization/65204
* tree-ssa-ccp.c (evaluate_stmt): Always evaluate address
takens for bit-CCP.
* gcc.dg/tree-ssa/ssa-ccp-35.c: New testcase.
Index: gcc/tree-ssa-ccp.c
===================================================================
--- gcc/tree-ssa-ccp.c (revision 220958)
+++ gcc/tree-ssa-ccp.c (working copy)
@@ -1748,7 +1769,9 @@ evaluate_stmt (gimple stmt)
/* Resort to simplification for bitwise tracking. */
if (flag_tree_bit_ccp
- && (likelyvalue == CONSTANT || is_gimple_call (stmt))
+ && (likelyvalue == CONSTANT || is_gimple_call (stmt)
+ || (gimple_assign_single_p (stmt)
+ && gimple_assign_rhs_code (stmt) == ADDR_EXPR))
&& !is_constant)
{
enum gimple_code code = gimple_code (stmt);
Index: gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-35.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-35.c (revision 0)
+++ gcc/testsuite/gcc.dg/tree-ssa/ssa-ccp-35.c (working copy)
@@ -0,0 +1,15 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-ccp1" } */
+
+typedef char char16[16] __attribute__ ((aligned (16)));
+char16 c16[4] __attribute__ ((aligned (4)));
+
+int f5 (int i)
+{
+ __SIZE_TYPE__ s = (__SIZE_TYPE__)&c16[i];
+ /* 0 */
+ return 3 & s;
+}
+
+/* { dg-final { scan-tree-dump "return 0;" "ccp1" } } */
+/* { dg-final { cleanup-tree-dump "ccp1" } } */
