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.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@121453 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 29 insertions, 6 deletions

diff --git a/gcc/emit-rtl.c b/gcc/emit-rtl.c
index aba4b7f7166..871ca386b02 100644
--- a/gcc/emit-rtl.c
+++ b/gcc/emit-rtl.c
@@ -1,6 +1,6 @@
 /* Emit RTL for the GCC expander.
    Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
-   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
+   1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
    Free Software Foundation, Inc.
 
 This file is part of GCC.
@@ -812,13 +812,12 @@ gen_reg_rtx (enum machine_mode mode)
   return val;
 }
 
-/* Generate a register with same attributes as REG, but offsetted by OFFSET.
+/* Update NEW with the same attributes as REG, but offsetted by OFFSET.
    Do the big endian correction if needed.  */
 
-rtx
-gen_rtx_REG_offset (rtx reg, enum machine_mode mode, unsigned int regno, int offset)
+static void
+update_reg_offset (rtx new, rtx reg, int offset)
 {
-  rtx new = gen_rtx_REG (mode, regno);
   tree decl;
   HOST_WIDE_INT var_size;
 
@@ -860,7 +859,7 @@ gen_rtx_REG_offset (rtx reg, enum machine_mode mode, unsigned int regno, int off
   if ((BYTES_BIG_ENDIAN || WORDS_BIG_ENDIAN)
       && decl != NULL
       && offset > 0
-      && GET_MODE_SIZE (GET_MODE (reg)) > GET_MODE_SIZE (mode)
+      && GET_MODE_SIZE (GET_MODE (reg)) > GET_MODE_SIZE (GET_MODE (new))
       && ((var_size = int_size_in_bytes (TREE_TYPE (decl))) > 0
 	  && var_size < GET_MODE_SIZE (GET_MODE (reg))))
     {
@@ -904,6 +903,30 @@ gen_rtx_REG_offset (rtx reg, enum machine_mode mode, unsigned int regno, int off
 
   REG_ATTRS (new) = get_reg_attrs (REG_EXPR (reg),
 				   REG_OFFSET (reg) + offset);
+}
+
+/* Generate a register with same attributes as REG, but offsetted by
+   OFFSET.  */
+
+rtx
+gen_rtx_REG_offset (rtx reg, enum machine_mode mode, unsigned int regno,
+		    int offset)
+{
+  rtx new = gen_rtx_REG (mode, regno);
+
+  update_reg_offset (new, reg, offset);
+  return new;
+}
+
+/* Generate a new pseudo-register with the same attributes as REG, but
+   offsetted by OFFSET.  */
+
+rtx
+gen_reg_rtx_offset (rtx reg, enum machine_mode mode, int offset)
+{
+  rtx new = gen_reg_rtx (mode);
+
+  update_reg_offset (new, reg, offset);
   return new;
 }