re PR tree-optimization/52975 (Ofast produces not optimized code for vectorized "converted if")

2012-04-16  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/52975
	* tree-ssa-forwprop.c (combine_cond_exprs): New function.
	(ssa_forward_propagate_and_combine): Call it for COND_EXPRs
	and VEC_COND_EXPRs.  Also combine into VEC_COND_EXPRs condition.
	* fold-const.c (operand_equal_p): Handle TARGET_MEM_REF.

From-SVN: r186488

gcc/ChangeLog

+2012-04-16  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/52975
+	* tree-ssa-forwprop.c (combine_cond_exprs): New function.
+	(ssa_forward_propagate_and_combine): Call it for COND_EXPRs
+	and VEC_COND_EXPRs.  Also combine into VEC_COND_EXPRs condition.
+	* fold-const.c (operand_equal_p): Handle TARGET_MEM_REF.
+
 2012-04-14  Uros Bizjak  <ubizjak@gmail.com>
 
 	* config/i386/sse.md (ssse3_plusminus): New code iterator.

gcc/fold-const.c

@@ -2562,6 +2562,14 @@ operand_equal_p (const_tree arg0, const_tree arg1, unsigned int flags)
 	case IMAGPART_EXPR:
 	  return OP_SAME (0);
 
+	case TARGET_MEM_REF:
+	  /* Require equal extra operands and then fall thru to MEM_REF
+	     handling of the two common operands.  */
+	  if (!OP_SAME_WITH_NULL (2)
+	      || !OP_SAME_WITH_NULL (3)
+	      || !OP_SAME_WITH_NULL (4))
+	    return 0;
+	  /* Fallthru.  */
 	case MEM_REF:
 	  /* Require equal access sizes, and similar pointer types.
 	     We can have incomplete types for array references of

gcc/tree-ssa-forwprop.c

@@ -632,6 +632,58 @@ forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
   return 0;
 }
 
+/* Propagate from the ssa name definition statements of COND_EXPR
+   values in the rhs of statement STMT into the conditional arms
+   if that simplifies it.
+   Returns true if the stmt was changed.  */
+
+static bool
+combine_cond_exprs (gimple_stmt_iterator *gsi_p)
+{
+  gimple stmt = gsi_stmt (*gsi_p);
+  tree cond, val1, val2;
+  bool changed = false;
+
+  cond = gimple_assign_rhs1 (stmt);
+  val1 = gimple_assign_rhs2 (stmt);
+  if (TREE_CODE (val1) == SSA_NAME)
+    {
+      gimple def_stmt = SSA_NAME_DEF_STMT (val1);
+      if (is_gimple_assign (def_stmt)
+	  && gimple_assign_rhs_code (def_stmt) == gimple_assign_rhs_code (stmt)
+	  && operand_equal_p (gimple_assign_rhs1 (def_stmt), cond, 0))
+	{
+	  val1 = unshare_expr (gimple_assign_rhs2 (def_stmt));
+	  gimple_assign_set_rhs2 (stmt, val1);
+	  changed = true;
+	}
+    }
+  val2 = gimple_assign_rhs3 (stmt);
+  if (TREE_CODE (val2) == SSA_NAME)
+    {
+      gimple def_stmt = SSA_NAME_DEF_STMT (val2);
+      if (is_gimple_assign (def_stmt)
+	  && gimple_assign_rhs_code (def_stmt) == gimple_assign_rhs_code (stmt)
+	  && operand_equal_p (gimple_assign_rhs1 (def_stmt), cond, 0))
+	{
+	  val2 = unshare_expr (gimple_assign_rhs3 (def_stmt));
+	  gimple_assign_set_rhs3 (stmt, val2);
+	  changed = true;
+	}
+    }
+  if (operand_equal_p (val1, val2, 0))
+    {
+      gimple_assign_set_rhs_from_tree (gsi_p, val1);
+      stmt = gsi_stmt (*gsi_p);
+      changed = true;
+    }
+
+  if (changed)
+    update_stmt (stmt);
+
+  return changed;
+}
+
 /* We've just substituted an ADDR_EXPR into stmt.  Update all the
    relevant data structures to match.  */
 
@@ -2480,10 +2532,12 @@ ssa_forward_propagate_and_combine (void)
 		     || code == NEGATE_EXPR)
 		    && TREE_CODE (rhs1) == SSA_NAME)
 		  changed = simplify_not_neg_expr (&gsi);
-		else if (code == COND_EXPR)
+		else if (code == COND_EXPR
+			 || code == VEC_COND_EXPR)
 		  {
 		    /* In this case the entire COND_EXPR is in rhs1. */
 		    changed |= forward_propagate_into_cond (&gsi);
+		    changed |= combine_cond_exprs (&gsi);
 		    stmt = gsi_stmt (gsi);
 		  }
 		else if (TREE_CODE_CLASS (code) == tcc_comparison)