[backport gcc-4.7/trunk r178109 <mikpe@it.uu.se>]

From: Richard Sandiford <richard dot sandiford at linaro dot org>
Subject: Passes uses rather than defs to df_set_dead_notes_for_mw
Date: Fri, 26 Aug 2011 14:54:12 +0100
List-Archive: <http://gcc.gnu.org/ml/gcc-patches/>

As described here:

    http://gcc.gnu.org/ml/gcc/2011-08/msg00294.html

df is currently failing to create REG_DEAD notes for the last use
of a multi-reg hard register.  This appears to be a typo:
df_set_dead_notes_for_mw is supposed to handle uses, and the comment
above it says so, but df_note_bb_compute is passing defs instead.

Bootstrapped & regression-tested on x86_64-linux-gnu.  OK to install?

Richard

gcc/

2011-08-26  Richard Sandiford  <richard.sandiford@linaro.org>

	* df-problems.c (df_note_bb_compute): Pass uses rather than defs
	to df_set_dead_notes_for_mw.

--- gcc-4.6.2/gcc/df-problems.c.~1~	2011-07-07 21:10:01.000000000 +0200
+++ gcc-4.6.2/gcc/df-problems.c	2011-12-27 13:04:09.000000000 +0100
@@ -3375,7 +3375,7 @@ df_note_bb_compute (unsigned int bb_inde
       while (*mws_rec)
 	{
 	  struct df_mw_hardreg *mws = *mws_rec;
-	  if ((DF_MWS_REG_DEF_P (mws))
+	  if (DF_MWS_REG_USE_P (mws)
 	      && !df_ignore_stack_reg (mws->start_regno))
 	    {
 	      bool really_add_notes = debug_insn != 0;