re PR middle-end/26134 (fold *(float*)(&complex_float_var) into REALPART_EXPR<complex_float_var>)

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.
	(non_rewritable_mem_ref_base): Handle complex type component
	accesses, constrain offsets for vector and complex extracts
	more properly.

	* gcc.dg/tree-ssa/complex-6.c: New testcase.

From-SVN: r171046

gcc/ChangeLog

 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.
+	(non_rewritable_mem_ref_base): Handle complex type component
+	accesses, constrain offsets for vector and complex extracts
+	more properly.
+
+2011-03-16  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/48146
 	* tree-ssa-sink.c (sink_code_in_bb): Manually update virtual
 	operands avoiding the need for renaming.

gcc/testsuite/ChangeLog

 2011-03-16  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/26134
+	* gcc.dg/tree-ssa/complex-6.c: New testcase.
+
+2011-03-16  Richard Guenther  <rguenther@suse.de>
+
 	PR tree-optimization/48146
 	* gcc.dg/torture/pr48146.c: New testcase.
 

gcc/testsuite/gcc.dg/tree-ssa/complex-6.c

+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-optimized" } */
+
+float
+quantum_real(float _Complex a)
+{
+  float *p = (float *) &a;
+  return p[0];
+}
+float
+quantum_imag(float _Complex a)
+{
+  float *p = (float *) &a;
+  return p[1];
+}
+float
+quantum_foo(float _Complex a)
+{
+  float *p = (float *) &a;
+  return p[2];
+}
+
+/* { dg-final { scan-tree-dump-times "REALPART_EXPR" 1 "optimized" } } */
+/* { dg-final { scan-tree-dump-times "IMAGPART_EXPR" 1 "optimized" } } */
+/* { dg-final { cleanup-tree-dump "optimized" } } */

gcc/tree-ssa.c

@@ -1855,6 +1855,14 @@ maybe_rewrite_mem_ref_base (tree *tp)
 					 bitsize_int (BITS_PER_UNIT),
 					 TREE_OPERAND (*tp, 1), 0));
 	}
+      else if (TREE_CODE (TREE_TYPE (sym)) == COMPLEX_TYPE
+	       && useless_type_conversion_p (TREE_TYPE (*tp),
+					     TREE_TYPE (TREE_TYPE (sym))))
+	{
+	  *tp = build1 (integer_zerop (TREE_OPERAND (*tp, 1))
+			? REALPART_EXPR : IMAGPART_EXPR,
+			TREE_TYPE (*tp), sym);
+	}
       else if (integer_zerop (TREE_OPERAND (*tp, 1)))
 	{
 	  if (!useless_type_conversion_p (TREE_TYPE (*tp),
@@ -1888,10 +1896,14 @@ non_rewritable_mem_ref_base (tree ref)
       && TREE_CODE (TREE_OPERAND (base, 0)) == ADDR_EXPR)
     {
       tree decl = TREE_OPERAND (TREE_OPERAND (base, 0), 0);
-      if (TREE_CODE (TREE_TYPE (decl)) == VECTOR_TYPE
+      if ((TREE_CODE (TREE_TYPE (decl)) == VECTOR_TYPE
+	   || TREE_CODE (TREE_TYPE (decl)) == COMPLEX_TYPE)
 	  && useless_type_conversion_p (TREE_TYPE (base),
 					TREE_TYPE (TREE_TYPE (decl)))
 	  && double_int_fits_in_uhwi_p (mem_ref_offset (base))
+	  && double_int_ucmp
+	       (tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (decl))),
+		mem_ref_offset (base)) == 1
 	  && multiple_of_p (sizetype, TREE_OPERAND (base, 1),
 			    TYPE_SIZE_UNIT (TREE_TYPE (base))))
 	return NULL_TREE;