re PR tree-optimization/48149 (Piecewise complex pass-through not optimized)

2011-03-16  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/48149
	* fold-const.c (fold_binary_loc): Fold
	COMPLEX_EXPR <REALPART_EXPR <x>, IMAGPART_EXPR <x>>.

	* gcc.dg/fold-complex-1.c: New testcase.

From-SVN: r171048

gcc/ChangeLog

 2011-03-16  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/48149
+	* fold-const.c (fold_binary_loc): Fold
+	COMPLEX_EXPR <REALPART_EXPR <x>, IMAGPART_EXPR <x>>.
+
+2011-03-16  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/26134
 	* tree-ssa.c (maybe_rewrite_mem_ref_base): Handle rewriting
 	complex part accesses to REALPART_EXPR and IMAGPART_EXPR.

gcc/fold-const.c

@@ -13176,6 +13176,14 @@ fold_binary_loc (location_t loc,
 	  || (TREE_CODE (arg0) == INTEGER_CST
 	      && TREE_CODE (arg1) == INTEGER_CST))
 	return build_complex (type, arg0, arg1);
+      if (TREE_CODE (arg0) == REALPART_EXPR
+	  && TREE_CODE (arg1) == IMAGPART_EXPR
+	  && (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (arg0, 0)))
+	      == TYPE_MAIN_VARIANT (type))
+	  && operand_equal_p (TREE_OPERAND (arg0, 0),
+			      TREE_OPERAND (arg1, 0), 0))
+	return omit_one_operand_loc (loc, type, TREE_OPERAND (arg0, 0),
+				     TREE_OPERAND (arg1, 0));
       return NULL_TREE;
 
     case ASSERT_EXPR:

gcc/testsuite/ChangeLog

 2011-03-16  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/48149
+	* gcc.dg/fold-complex-1.c: New testcase.
+
+2011-03-16  Richard Guenther  <rguenther@suse.de>
+
 	PR testsuite/48147
 	* gcc.dg/guality/pr45882.c: Really make sure no inlining
 	or cloning happens.

gcc/testsuite/gcc.dg/fold-complex-1.c

+/* { dg-do compile } */
+/* { dg-options "-O -ffast-math -fdump-tree-original" } */
+
+_Complex float
+foo (_Complex float x)
+{
+  return  __real x + 1.0iF * __imag x;
+}
+
+/* { dg-final { scan-tree-dump-times "COMPLEX_EXPR" 0 "original" } } */
+/* { dg-final { cleanup-tree-dump "original" } } */