[patch committed SH] Fix PR target/65249

[Kaz Kojima]

The attached patches are to fix PR target/65249 which is a 4.9/5
regression.  It avoids yet another R0_REGS spill failure with
pre-allocating R0 reg in symGOT_load when the loading symbol is
__stack_chk_guard.  Although the problem went away with -mlra
and LRA would be the real fix for this issue, SH is still in
transition to LRA and we have no chance for 4.9.
Tested with sh4-unknown-linux-gnu on trunk and 4.9 branch.
Committed on trunk and 4.9.

Regards,
	kaz
--
2015-03-03  Kaz Kojima  <kkojima@gcc.gnu.org>

	PR target/65249
	* config/sh/sh.md (symGOT_load): Use R0 reg for operands[2] when
	called for __stack_chk_guard symbol.

[trunk/gcc]
diff --git a/config/sh/sh.md b/config/sh/sh.md
index 2435ec9..24ddc9e 100644
--- a/config/sh/sh.md
+++ b/config/sh/sh.md
@@ -10690,10 +10690,26 @@ label:
   ""
 {
   rtx mem;
+  bool stack_chk_guard_p = false;
 
   operands[2] = !can_create_pseudo_p () ? operands[0] : gen_reg_rtx (Pmode);
   operands[3] = !can_create_pseudo_p () ? operands[0] : gen_reg_rtx (Pmode);
 
+  if (!TARGET_SHMEDIA
+      && flag_stack_protect
+      && GET_CODE (operands[1]) == CONST
+      && GET_CODE (XEXP (operands[1], 0)) == UNSPEC
+      && GET_CODE (XVECEXP (XEXP (operands[1], 0), 0, 0)) == SYMBOL_REF
+      && strcmp (XSTR (XVECEXP (XEXP (operands[1], 0), 0, 0), 0),
+		 "__stack_chk_guard") == 0)
+    stack_chk_guard_p = true;
+
+  /* Use R0 to avoid long R0 liveness which stack-protector tends to
+     produce.  */
+  if (! sh_lra_flag
+      && stack_chk_guard_p && ! reload_in_progress && ! reload_completed)
+    operands[2] = gen_rtx_REG (Pmode, R0_REG);
+
   if (TARGET_SHMEDIA)
     {
       rtx reg = operands[2];
@@ -10721,13 +10737,7 @@ label:
      insn to avoid combining (set A (plus rX r12)) and (set op0 (mem A))
      when rX is a GOT address for the guard symbol.  Ugly but doesn't
      matter because this is a rare situation.  */
-  if (!TARGET_SHMEDIA
-      && flag_stack_protect
-      && GET_CODE (operands[1]) == CONST
-      && GET_CODE (XEXP (operands[1], 0)) == UNSPEC
-      && GET_CODE (XVECEXP (XEXP (operands[1], 0), 0, 0)) == SYMBOL_REF
-      && strcmp (XSTR (XVECEXP (XEXP (operands[1], 0), 0, 0), 0),
-		 "__stack_chk_guard") == 0)
+  if (stack_chk_guard_p)
     emit_insn (gen_chk_guard_add (operands[3], operands[2]));
   else
     emit_move_insn (operands[3], gen_rtx_PLUS (Pmode, operands[2],
[gcc-4_9-branch/gcc]
diff --git a/config/sh/sh.md b/config/sh/sh.md
index 00bbf3e..f75f5a2 100644
--- a/config/sh/sh.md
+++ b/config/sh/sh.md
@@ -10164,10 +10164,25 @@ label:
   ""
 {
   rtx mem;
+  bool stack_chk_guard_p = false;
 
   operands[2] = !can_create_pseudo_p () ? operands[0] : gen_reg_rtx (Pmode);
   operands[3] = !can_create_pseudo_p () ? operands[0] : gen_reg_rtx (Pmode);
 
+  if (!TARGET_SHMEDIA
+      && flag_stack_protect
+      && GET_CODE (operands[1]) == CONST
+      && GET_CODE (XEXP (operands[1], 0)) == UNSPEC
+      && GET_CODE (XVECEXP (XEXP (operands[1], 0), 0, 0)) == SYMBOL_REF
+      && strcmp (XSTR (XVECEXP (XEXP (operands[1], 0), 0, 0), 0),
+		 "__stack_chk_guard") == 0)
+    stack_chk_guard_p = true;
+
+  /* Use R0 to avoid long R0 liveness which stack-protector tends to
+     produce.  */
+  if (stack_chk_guard_p && ! reload_in_progress && ! reload_completed)
+    operands[2] = gen_rtx_REG (Pmode, R0_REG);
+
   if (TARGET_SHMEDIA)
     {
       rtx reg = operands[2];
@@ -10195,13 +10210,7 @@ label:
      insn to avoid combining (set A (plus rX r12)) and (set op0 (mem A))
      when rX is a GOT address for the guard symbol.  Ugly but doesn't
      matter because this is a rare situation.  */
-  if (!TARGET_SHMEDIA
-      && flag_stack_protect
-      && GET_CODE (operands[1]) == CONST
-      && GET_CODE (XEXP (operands[1], 0)) == UNSPEC
-      && GET_CODE (XVECEXP (XEXP (operands[1], 0), 0, 0)) == SYMBOL_REF
-      && strcmp (XSTR (XVECEXP (XEXP (operands[1], 0), 0, 0), 0),
-		 "__stack_chk_guard") == 0)
+  if (stack_chk_guard_p)
     emit_insn (gen_chk_guard_add (operands[3], operands[2]));
   else
     emit_move_insn (operands[3], gen_rtx_PLUS (Pmode, operands[2],