[PATCH] LRA: Fix caller-save store/restore instruction for large mode

[Kito Cheng]

Hi Vladimir:
  This patch has a discusses with you in May 2014, this patch is about
the caller-save register store and restore instruction generation, the
current LRA implementation will miss caller-save store/restore
instruction if need one more instruction.

You said you will investigate for this on IRC, so I don't send the
patch last year, however ARM guys seem got this problem too, so I
think it's time to send this patch :)

ChangeLog

2015-01-05  Kito Cheng  <k...@0xlab.org>

        * lra-constraints.c (split_reg): Fix caller-save store/restore
instruction generation.

From 434dc294cf3f2267eed89d27b34c53c079e2b25a Mon Sep 17 00:00:00 2001
From: Kito Cheng <k...@andestech.com>
Date: Thu, 29 May 2014 23:53:23 +0800
Subject: [PATCH] Fix caller-save store/restore instruction for large mode in
 lra

 - The original code assume store/restore will always have only
   one insn, it's will fail if you split in move pattern!!!
---
 gcc/lra-constraints.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index 382281c..4dcf553 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -4918,9 +4918,8 @@ split_reg (bool before_p, int original_regno, rtx_insn *insn,
       reg_renumber[REGNO (new_reg)] = hard_regno;
     }
   save = emit_spill_move (true, new_reg, original_reg);
-  if (NEXT_INSN (save) != NULL_RTX)
+  if (NEXT_INSN (save) != NULL_RTX && !call_save_p)
     {
-      lra_assert (! call_save_p);
       if (lra_dump_file != NULL)
 	{
 	  fprintf
@@ -4934,9 +4933,8 @@ split_reg (bool before_p, int original_regno, rtx_insn *insn,
       return false;
     }
   restore = emit_spill_move (false, new_reg, original_reg);
-  if (NEXT_INSN (restore) != NULL_RTX)
+  if (NEXT_INSN (restore) != NULL_RTX && !call_save_p)
     {
-      lra_assert (! call_save_p);
       if (lra_dump_file != NULL)
 	{
 	  fprintf (lra_dump_file,
-- 
1.7.6