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[patch committed] SH: Fix PR target/32163
- From: Kaz Kojima <kkojima at rr dot iij4u dot or dot jp>
- To: gcc-patches at gcc dot gnu dot org
- Date: Sun, 03 Jun 2007 13:40:22 +0900 (JST)
- Subject: [patch committed] SH: Fix PR target/32163
Hi,
I've applied the attached patch on trunk to fix PR target/32163.
In the faulty case, stack protector inserts PIC insns after
the result is set to R0 register but optimizers turn them into
the insn which requires R0. Then we get a yet another R0 spill
failure. The patch stops such insns from scheduling. This is
not a good solution but would be enough for this rare situation.
It's tested with bootstrap and the top level "make -k check" on
sh4-unknown-linux-gnu with no new failures. I'll apply this
patch to 4.1/4.2 too, after the same tests done. I think that
this PR would be a regression from 4.0 when the most secure
options are needed as gcc options.
Regards,
kaz
--
2007-06-03 Kaz Kojima <kkojima@gcc.gnu.org>
PR target/32163
* config/sh/sh.md (symGOT_load): Don't schedule insns when
the symbol is generated with the stack protector.
--- ORIG/trunk/gcc/config/sh/sh.md 2007-04-27 21:30:47.000000000 +0900
+++ LOCAL/trunk/gcc/config/sh/sh.md 2007-06-01 08:21:18.000000000 +0900
@@ -8502,6 +8502,20 @@ label:
operands[2],
gen_rtx_REG (Pmode, PIC_REG)));
+ /* When stack protector inserts codes after the result is set to
+ R0, @(rX, r12) will cause a spill failure for R0. Don't schedule
+ insns 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)
+ emit_insn (gen_blockage ());
+
/* N.B. This is not constant for a GOTPLT relocation. */
mem = gen_rtx_MEM (Pmode, operands[3]);
MEM_NOTRAP_P (mem) = 1;