re PR tree-optimization/49343 (ICE on field with variable offset)

2011-06-16  Martin Jambor  <mjambor@suse.cz>

	PR tree-optimization/49343
	* tree-sra.c (build_ref_for_model): Use component_ref_field_offset to
	calculate offset, provide 2nd operand for the new COMPONENT_REF.

	* testsuite/gnat.dg/discr31.adb: New test.
	* testsuite/gnat.dg/discr31.ads: Likewise.

From-SVN: r175111

gcc/ChangeLog

+2011-06-16  Martin Jambor  <mjambor@suse.cz>
+
+	PR tree-optimization/49343
+	* tree-sra.c (build_ref_for_model): Use component_ref_field_offset to
+	calculate offset, provide 2nd operand for the new COMPONENT_REF.
+
 2011-06-16  Iain Sandoe  <iains@gcc.gnu.org>
 
 	* config/darwin-protos.h (machopic_select_rtx_section): Move to

gcc/testsuite/ChangeLog

+2011-06-16  Martin Jambor  <mjambor@suse.cz>
+
+	PR tree-optimization/49343
+	* gnat.dg/discr31.adb: New test.
+	* gnat.dg/discr31.ads: Likewise.
+
 2011-06-16  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* gcc.dg/debug/pr49032.c: Prune mips-tfile warning.

gcc/testsuite/gnat.dg/discr31.adb

+-- { dg-do compile }
+-- { dg-options "-O" }
+
+package body Discr31 is
+
+   function Log_Item(Packet : in Packet_Data_Type) return Log_Item_Type is
+      None : Log_Item_Type(0);
+   begin
+      return None;
+   end;
+
+end Discr31;

gcc/testsuite/gnat.dg/discr31.ads

+package Discr31 is
+
+   type Byte_List_Type is array(Positive range <>) of Integer;
+
+   type Log_Item_Type(Last : Natural) is record
+      Data : Byte_List_Type(1 .. Last) := (others => 0);
+      Link : Natural := 0;
+   end record;
+
+   type Packet_Data_Type is access Log_Item_Type;
+
+   function Log_Item(Packet : in Packet_Data_Type) return Log_Item_Type;
+
+end Discr31;

gcc/tree-sra.c

@@ -1421,12 +1421,16 @@ build_ref_for_model (location_t loc, tree base, HOST_WIDE_INT offset,
 {
   if (TREE_CODE (model->expr) == COMPONENT_REF)
     {
-      tree t, exp_type;
-      offset -= int_bit_position (TREE_OPERAND (model->expr, 1));
+      tree t, exp_type, fld = TREE_OPERAND (model->expr, 1);
+      tree cr_offset = component_ref_field_offset (model->expr);
+
+      gcc_assert (cr_offset && host_integerp (cr_offset, 1));
+      offset -= TREE_INT_CST_LOW (cr_offset) * BITS_PER_UNIT;
+      offset -= TREE_INT_CST_LOW (DECL_FIELD_BIT_OFFSET (fld));
       exp_type = TREE_TYPE (TREE_OPERAND (model->expr, 0));
       t = build_ref_for_offset (loc, base, offset, exp_type, gsi, insert_after);
-      return fold_build3_loc (loc, COMPONENT_REF, model->type, t,
-			      TREE_OPERAND (model->expr, 1), NULL_TREE);
+      return fold_build3_loc (loc, COMPONENT_REF, model->type, t, fld,
+			      TREE_OPERAND (model->expr, 2));
     }
   else
     return build_ref_for_offset (loc, base, offset, model->type,