lower-subreg.c: New file.

gcc/:
	* lower-subreg.c: New file.
	* rtl.def (CONCATN): Define.
	* passes.c (init_optimization_passes): Add pass_lower_subreg and
	pass_lower_subreg2.
	* emit-rtl.c (update_reg_offset): New static function, broken out
	of gen_rtx_REG_offset.
	(gen_rtx_REG_offset): Call update_reg_offset.
	(gen_reg_rtx_offset): New function.
	* regclass.c: Revert patch of 2006-03-05, restoring
	reg_scan_update.
	(clear_reg_info_regno): New function.
	* dwarf2out.c (concatn_loc_descriptor): New static function.
	(loc_descriptor): Handle CONCATN.
	* common.opt (fsplit_wide_types): New option.
	* opts.c (decode_options): Set flag_split_wide_types when
	optimizing.
	* timevar.def (TV_LOWER_SUBREG): Define.
	* rtl.h (gen_reg_rtx_offset): Declare.
	(reg_scan_update): Declare.
	* regs.h (clear_reg_info_regno): Declare.
	* tree-pass.h (pass_lower_subreg): Declare.
	(pass_lower_subreg2): Declare.
	* doc/invoke.texi (Option Summary): List -fno-split-wide-types.
	(Optimize Options): Add -fsplit-wide-types to -O1 list.  Document
	-fsplit-wide-types.
	* doc/rtl.texi (Regs and Memory): Document concat and concatn.
	* Makefile.in (OBJS-common): Add lower-subreg.o.
	(lower-subreg.o): New target.
gcc/testsuite/:
	* gcc.dg/lower-subreg-1.c (test): New test.

From-SVN: r121453

1 files changed, 31 insertions, 1 deletions

diff --git a/gcc/dwarf2out.c b/gcc/dwarf2out.c
index 2968d3b..861ede5 100644
--- a/gcc/dwarf2out.c
+++ b/gcc/dwarf2out.c
@@ -1,6 +1,6 @@
 /* Output Dwarf2 format symbol table information from GCC.
    Copyright (C) 1992, 1993, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
-   2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+   2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
    Contributed by Gary Funck (gary@intrepid.com).
    Derived from DWARF 1 implementation of Ron Guilmette (rfg@monkeys.com).
    Extensively modified by Jason Merrill (jason@cygnus.com).
@@ -9043,6 +9043,32 @@ concat_loc_descriptor (rtx x0, rtx x1)
   return cc_loc_result;
 }
 
+/* Return a descriptor that describes the concatenation of N
+   locations.  */
+
+static dw_loc_descr_ref
+concatn_loc_descriptor (rtx concatn)
+{
+  unsigned int i;
+  dw_loc_descr_ref cc_loc_result = NULL;
+  unsigned int n = XVECLEN (concatn, 0);
+
+  for (i = 0; i < n; ++i)
+    {
+      dw_loc_descr_ref ref;
+      rtx x = XVECEXP (concatn, 0, i);
+
+      ref = loc_descriptor (x);
+      if (ref == NULL)
+	return NULL;
+
+      add_loc_descr (&cc_loc_result, ref);
+      add_loc_descr_op_piece (&cc_loc_result, GET_MODE_SIZE (GET_MODE (x)));
+    }
+
+  return cc_loc_result;
+}
+
 /* Output a proper Dwarf location descriptor for a variable or parameter
    which is either allocated in a register or in a memory location.  For a
    register, we just generate an OP_REG and the register number.  For a
@@ -9080,6 +9106,10 @@ loc_descriptor (rtx rtl)
       loc_result = concat_loc_descriptor (XEXP (rtl, 0), XEXP (rtl, 1));
       break;
 
+    case CONCATN:
+      loc_result = concatn_loc_descriptor (rtl);
+      break;
+
     case VAR_LOCATION:
       /* Single part.  */
       if (GET_CODE (XEXP (rtl, 1)) != PARALLEL)