[PATCH] Fix PR56150

[Richard Biener]

This fixes PR56150 - mixed store/loads are not equal.

Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.

Richard.

2013-01-30  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/56150
        * tree-ssa-tail-merge.c (gimple_equal_p): Properly handle
        mixed store non-store stmts.

        * gcc.dg/torture/pr56150.c: New testcase.

Index: gcc/tree-ssa-tail-merge.c
===================================================================
*** gcc/tree-ssa-tail-merge.c   (revision 195574)
--- gcc/tree-ssa-tail-merge.c   (working copy)
*************** gimple_equal_p (same_succ same_succ, gim
*** 1119,1135 ****
      case GIMPLE_ASSIGN:
        lhs1 = gimple_get_lhs (s1);
        lhs2 = gimple_get_lhs (s2);
!       if (gimple_vdef (s1))
!       {
!         if (vn_valueize (gimple_vdef (s1)) != vn_valueize (gimple_vdef (s2)))
!           return false;
!         if (TREE_CODE (lhs1) != SSA_NAME
!             && TREE_CODE (lhs2) != SSA_NAME)
!           return true;
!       }
!       return (TREE_CODE (lhs1) == SSA_NAME
!             && TREE_CODE (lhs2) == SSA_NAME
!             && vn_valueize (lhs1) == vn_valueize (lhs2));
  
      case GIMPLE_COND:
        t1 = gimple_cond_lhs (s1);
--- 1119,1132 ----
      case GIMPLE_ASSIGN:
        lhs1 = gimple_get_lhs (s1);
        lhs2 = gimple_get_lhs (s2);
!       if (TREE_CODE (lhs1) != SSA_NAME
!         && TREE_CODE (lhs2) != SSA_NAME)
!       return (vn_valueize (gimple_vdef (s1))
!               == vn_valueize (gimple_vdef (s2)));
!       else if (TREE_CODE (lhs1) == SSA_NAME
!              && TREE_CODE (lhs2) == SSA_NAME)
!       return vn_valueize (lhs1) == vn_valueize (lhs2);
!       return false;
  
      case GIMPLE_COND:
        t1 = gimple_cond_lhs (s1);
Index: gcc/testsuite/gcc.dg/torture/pr56150.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr56150.c      (revision 0)
--- gcc/testsuite/gcc.dg/torture/pr56150.c      (working copy)
***************
*** 0 ****
--- 1,17 ----
+ /* { dg-do compile } */
+ 
+ struct {
+     int f4;
+ } g1;
+ 
+ long g2;
+ 
+ volatile long g3;
+ 
+ void func_1 ()
+ {
+   if (g2)
+     g1 = g1;
+   else
+     g3;
+ }