diff mbox

[committed,SH] Fix PR target/64533

Message ID 20150108.180553.271651358.kkojima@rr.iij4u.or.jp
State New
Headers show

Commit Message

Kaz Kojima Jan. 8, 2015, 9:05 a.m. UTC 
I've committed the attached patch to fix PR target/64533
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64533
which is a 5.0 regression.
Splitting rA := rB + N to rA := N and rA := rA + rB isn't
safe when rA is the stack pointer.  If someone interrupts
between these 2 set insns, we could see a bad value in
the stack pointer.  I've got a few sporadic and unreproducible
errors in libjava testsuite on sh-linux because of this.
The attached one liner is to avoid that splitting when rA
is the stack pointer.  Tested on sh4-unknown-linux-gnu with
no new failures.

Regards,
	kaz
--
2015-01-08  Kaz Kojima  <kkojima@gcc.gnu.org>

	PR target/64533
	* config/sh/sh.md (*addsi3_compact): Use u constraint instead
	of r for the second alternative of the destination operand.
diff mbox

Patch

diff --git a/gcc/config/sh/sh.md b/gcc/config/sh/sh.md
index 37d2a20..6e0b97f 100644
--- a/gcc/config/sh/sh.md
+++ b/gcc/config/sh/sh.md
@@ -2061,9 +2061,10 @@ 
 ;; The problem is that LRA expects something like
 ;;    (set rA (plus rB (const_int N)))
 ;; to work.  We can do that, but we have to split out an additional reg-reg
-;; copy before the actual add insn.
+;; copy before the actual add insn.  Use u constraint for that case to avoid
+;; the invalid value in the stack pointer.
 (define_insn_and_split "*addsi3_compact"
-  [(set (match_operand:SI 0 "arith_reg_dest" "=r,&r")
+  [(set (match_operand:SI 0 "arith_reg_dest" "=r,&u")
 	(plus:SI (match_operand:SI 1 "arith_operand" "%0,r")
 		 (match_operand:SI 2 "arith_or_int_operand" "rI08,rn")))]
   "TARGET_SH1