[PATCH] Fix SH/FDPIC bad codegen with ssp enabled

[Rich Felker]

The "chk_guard_add" pattern used for loading the GOT slot address for
__stack_chk_guard hard-codes use of r12 as a fixed GOT register and
thus is not suitable for FDPIC, where the saved initial value of r12
from function entry is what we need.

I would actually prefer removing this hack entirely if possible. I
tried non-FDPIC with it disabled and did not experience any problems;
I suspect it was written to work around a bug that no longer exists.

2015-11-13  Rich Felker <dalias@libc.org>

	gcc/
	* config/sh/sh.md (symGOT_load): Suppress __stack_chk_guard
	address loading hack for FDPIC targets.

diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index 7a40d0f..45c9995 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -11082,7 +11082,7 @@ (define_expand "symGOT_load"
   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
+  if (!TARGET_SHMEDIA && !TARGET_FDPIC
       && flag_stack_protect
       && GET_CODE (operands[1]) == CONST
       && GET_CODE (XEXP (operands[1], 0)) == UNSPEC