[PATCH] Simplify condition in [VEC_]COND_EXPR

[Richard Biener]

This makes us first simplify the embedded GENERIC condition in 
[VEC_]COND_EXPRs when invoking the match-and-simplify machinery.

Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.

Richard.

2015-07-31  Richard Biener  <rguent...@suse.de>

        * gimple-match-head.c (gimple_simplify): For [VEC_]COND_EXPRs
        on the rhs of assignments first simplify the embedded
        GENERIC condition.

Index: gcc/gimple-match-head.c
===================================================================
--- gcc/gimple-match-head.c     (revision 226429)
+++ gcc/gimple-match-head.c     (working copy)
@@ -660,10 +660,43 @@ gimple_simplify (gimple stmt,
            }
          case GIMPLE_TERNARY_RHS:
            {
+             bool valueized = false;
              tree rhs1 = gimple_assign_rhs1 (stmt);
+             /* If this is a [VEC_]COND_EXPR first try to simplify an
+                embedded GENERIC condition.  */
+             if (code == COND_EXPR
+                 || code == VEC_COND_EXPR)
+               {
+                 if (COMPARISON_CLASS_P (rhs1))
+                   {
+                     tree lhs = TREE_OPERAND (rhs1, 0);
+                     tree rhs = TREE_OPERAND (rhs1, 1);
+                     lhs = do_valueize (lhs, top_valueize, valueized);
+                     rhs = do_valueize (rhs, top_valueize, valueized);
+                     code_helper rcode2 = TREE_CODE (rhs1);
+                     tree ops2[3] = {};
+                     ops2[0] = lhs;
+                     ops2[1] = rhs;
+                     if ((gimple_resimplify2 (seq, &rcode2, TREE_TYPE (rhs1),
+                                              ops2, valueize)
+                          || valueized)
+                         && rcode2.is_tree_code ())
+                       {
+                         valueized = true;
+                         if (TREE_CODE_CLASS ((enum tree_code)rcode2)
+                             == tcc_comparison)
+                           rhs1 = build2 (rcode2, TREE_TYPE (rhs1),
+                                          ops2[0], ops2[1]);
+                         else if (rcode2 == SSA_NAME
+                                  || rcode2 == INTEGER_CST)
+                           rhs1 = ops2[0];
+                         else
+                           valueized = false;
+                       }
+                   }
+               }
              tree rhs2 = gimple_assign_rhs2 (stmt);
              tree rhs3 = gimple_assign_rhs3 (stmt);
-             bool valueized = false;
              rhs1 = do_valueize (rhs1, top_valueize, valueized);
              rhs2 = do_valueize (rhs2, top_valueize, valueized);
              rhs3 = do_valueize (rhs3, top_valueize, valueized);