forked from rpms/qemu-kvm
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
102 lines
3.2 KiB
102 lines
3.2 KiB
9 months ago
|
From a280a700fb016178776cb599d8cf918185df8697 Mon Sep 17 00:00:00 2001
|
||
|
|
From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@redhat.com>
|
||
|
|
Date: Tue, 23 May 2023 12:34:33 +0200
|
||
|
|
Subject: [PATCH 11/22] target/s390x: Fix determination of overflow condition
|
||
|
|
code after subtraction
|
||
|
|
MIME-Version: 1.0
|
||
|
|
Content-Type: text/plain; charset=UTF-8
|
||
|
|
Content-Transfer-Encoding: 8bit
|
||
|
|
|
||
|
|
RH-Author: Cédric Le Goater <clg@redhat.com>
|
||
|
|
RH-MergeRequest: 279: Backport latest s390x-related fixes from upstream QEMU for qemu-kvm in RHEL 8.9
|
||
|
|
RH-Bugzilla: 2169308 2209605
|
||
|
|
RH-Acked-by: Thomas Huth <thuth@redhat.com>
|
||
|
|
RH-Acked-by: David Hildenbrand <david@redhat.com>
|
||
|
|
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
|
||
|
|
RH-Commit: [10/21] 14792faddfca784503f89c292ebaba5be8d3fc96
|
||
|
|
|
||
|
|
Bugzilla: https://bugzilla.redhat.com/2169308
|
||
|
|
|
||
|
|
commit fc6e0d0f2db5126592bb4066d484fcdfc14ccf36
|
||
|
|
Author: Bruno Haible <bruno@clisp.org>
|
||
|
|
Date: Wed Mar 23 17:26:21 2022 +0100
|
||
|
|
|
||
|
|
target/s390x: Fix determination of overflow condition code after subtraction
|
||
|
|
|
||
|
|
Reported by Paul Eggert in
|
||
|
|
https://lists.gnu.org/archive/html/bug-gnulib/2021-09/msg00050.html
|
||
|
|
|
||
|
|
This program currently prints different results when run with TCG instead
|
||
|
|
of running on real s390x hardware:
|
||
|
|
|
||
|
|
#include <stdio.h>
|
||
|
|
|
||
|
|
int overflow_32 (int x, int y)
|
||
|
|
{
|
||
|
|
int sum;
|
||
|
|
return __builtin_sub_overflow (x, y, &sum);
|
||
|
|
}
|
||
|
|
|
||
|
|
int overflow_64 (long long x, long long y)
|
||
|
|
{
|
||
|
|
long sum;
|
||
|
|
return __builtin_sub_overflow (x, y, &sum);
|
||
|
|
}
|
||
|
|
|
||
|
|
int a1 = 0;
|
||
|
|
int b1 = -2147483648;
|
||
|
|
long long a2 = 0L;
|
||
|
|
long long b2 = -9223372036854775808L;
|
||
|
|
|
||
|
|
int main ()
|
||
|
|
{
|
||
|
|
{
|
||
|
|
int a = a1;
|
||
|
|
int b = b1;
|
||
|
|
printf ("a = 0x%x, b = 0x%x\n", a, b);
|
||
|
|
printf ("no_overflow = %d\n", ! overflow_32 (a, b));
|
||
|
|
}
|
||
|
|
{
|
||
|
|
long long a = a2;
|
||
|
|
long long b = b2;
|
||
|
|
printf ("a = 0x%llx, b = 0x%llx\n", a, b);
|
||
|
|
printf ("no_overflow = %d\n", ! overflow_64 (a, b));
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
Signed-off-by: Bruno Haible <bruno@clisp.org>
|
||
|
|
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/618
|
||
|
|
Message-Id: <20220323162621.139313-3-thuth@redhat.com>
|
||
|
|
Signed-off-by: Thomas Huth <thuth@redhat.com>
|
||
|
|
|
||
|
|
Signed-off-by: Cédric Le Goater <clg@redhat.com>
|
||
|
|
---
|
||
|
|
target/s390x/tcg/cc_helper.c | 4 ++--
|
||
|
|
1 file changed, 2 insertions(+), 2 deletions(-)
|
||
|
|
|
||
|
|
diff --git a/target/s390x/tcg/cc_helper.c b/target/s390x/tcg/cc_helper.c
|
||
|
|
index e11cdb745d..b2e8d3d9f5 100644
|
||
|
|
--- a/target/s390x/tcg/cc_helper.c
|
||
|
|
+++ b/target/s390x/tcg/cc_helper.c
|
||
|
|
@@ -151,7 +151,7 @@ static uint32_t cc_calc_add_64(int64_t a1, int64_t a2, int64_t ar)
|
||
|
|
|
||
|
|
static uint32_t cc_calc_sub_64(int64_t a1, int64_t a2, int64_t ar)
|
||
|
|
{
|
||
|
|
- if ((a1 > 0 && a2 < 0 && ar < 0) || (a1 < 0 && a2 > 0 && ar > 0)) {
|
||
|
|
+ if ((a1 >= 0 && a2 < 0 && ar < 0) || (a1 < 0 && a2 > 0 && ar > 0)) {
|
||
|
|
return 3; /* overflow */
|
||
|
|
} else {
|
||
|
|
if (ar < 0) {
|
||
|
|
@@ -211,7 +211,7 @@ static uint32_t cc_calc_add_32(int32_t a1, int32_t a2, int32_t ar)
|
||
|
|
|
||
|
|
static uint32_t cc_calc_sub_32(int32_t a1, int32_t a2, int32_t ar)
|
||
|
|
{
|
||
|
|
- if ((a1 > 0 && a2 < 0 && ar < 0) || (a1 < 0 && a2 > 0 && ar > 0)) {
|
||
|
|
+ if ((a1 >= 0 && a2 < 0 && ar < 0) || (a1 < 0 && a2 > 0 && ar > 0)) {
|
||
|
|
return 3; /* overflow */
|
||
|
|
} else {
|
||
|
|
if (ar < 0) {
|
||
|
|
--
|
||
|
|
2.37.3
|
||
|
|
|