From 4ce7a1e0aaecb220016af9b4f390b76f7fffcce8 Mon Sep 17 00:00:00 2001
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Wed, 19 Sep 2012 21:40:30 +0200
Subject: [PATCH] tcg/optimize: fix end of basic block detection
Commit e31b0a7c050711884ad570fe73df806520953618 fixed copy propagation on
32-bit host by restricting the copy between different types. This was the
wrong fix.
The real problem is that the all temps states should be reset at the end
of a basic block. This was done by adding such operations in the switch,
but brcond2 was forgotten (that's why the crash was only observed on 32-bit
hosts).
Fix that by looking at the TCG_OPF_BB_END instead. We need to keep the case
for op_set_label as temps might be modified through another path.
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
tcg/optimize.c | 22 +++++++++-------------
1 file changed, 9 insertions(+), 13 deletions(-)
diff --git a/tcg/optimize.c b/tcg/optimize.c
index 10d9773..9da333c 100644
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -632,21 +632,17 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr,
i--;
}
break;
- case INDEX_op_set_label:
- case INDEX_op_jmp:
- case INDEX_op_br:
- memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
- for (i = 0; i < def->nb_args; i++) {
- *gen_args = *args;
- args++;
- gen_args++;
- }
- break;
default:
/* Default case: we do know nothing about operation so no
- propagation is done. We only trash output args. */
- for (i = 0; i < def->nb_oargs; i++) {
- reset_temp(args[i], nb_temps, nb_globals);
+ propagation is done. We trash everything if the operation
+ is the end of a basic block, otherwise we only trash the
+ output args. */
+ if (def->flags & TCG_OPF_BB_END) {
+ memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info));
+ } else {
+ for (i = 0; i < def->nb_oargs; i++) {
+ reset_temp(args[i], nb_temps, nb_globals);
+ }
}
for (i = 0; i < def->nb_args; i++) {
gen_args[i] = args[i];
--
1.7.12.1