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99 lines
3.1 KiB
99 lines
3.1 KiB
1 year ago
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From 2ddea7186ae50c1f29d790027e8aa98894e51694 Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@redhat.com>
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Date: Tue, 23 May 2023 12:34:33 +0200
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Subject: [PATCH 10/22] target/s390x: Fix determination of overflow condition
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code after addition
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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RH-Author: Cédric Le Goater <clg@redhat.com>
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RH-MergeRequest: 279: Backport latest s390x-related fixes from upstream QEMU for qemu-kvm in RHEL 8.9
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RH-Bugzilla: 2169308 2209605
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RH-Acked-by: Thomas Huth <thuth@redhat.com>
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RH-Acked-by: David Hildenbrand <david@redhat.com>
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RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
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RH-Commit: [9/21] e8b946ff4e521e0367cb03fcd918a2f8af8bd4d5
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Bugzilla: https://bugzilla.redhat.com/2169308
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commit 5a2e67a691501bc4dd81c46c81b8f1881c8bd5df
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Author: Bruno Haible <bruno@clisp.org>
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Date: Wed Mar 23 17:26:20 2022 +0100
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target/s390x: Fix determination of overflow condition code after addition
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This program currently prints different results when run with TCG instead
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of running on real s390x hardware:
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#include <stdio.h>
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int overflow_32 (int x, int y)
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{
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int sum;
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return ! __builtin_add_overflow (x, y, &sum);
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}
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int overflow_64 (long long x, long long y)
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{
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long sum;
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return ! __builtin_add_overflow (x, y, &sum);
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}
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int a1 = -2147483648;
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int b1 = -2147483648;
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long long a2 = -9223372036854775808L;
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long long b2 = -9223372036854775808L;
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int main ()
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{
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{
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int a = a1;
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int b = b1;
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printf ("a = 0x%x, b = 0x%x\n", a, b);
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printf ("no_overflow = %d\n", overflow_32 (a, b));
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}
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{
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long long a = a2;
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long long b = b2;
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printf ("a = 0x%llx, b = 0x%llx\n", a, b);
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printf ("no_overflow = %d\n", overflow_64 (a, b));
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}
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}
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Signed-off-by: Bruno Haible <bruno@clisp.org>
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Resolves: https://gitlab.com/qemu-project/qemu/-/issues/616
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Message-Id: <20220323162621.139313-2-thuth@redhat.com>
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Signed-off-by: Thomas Huth <thuth@redhat.com>
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Signed-off-by: Cédric Le Goater <clg@redhat.com>
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---
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target/s390x/tcg/cc_helper.c | 4 ++--
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1 file changed, 2 insertions(+), 2 deletions(-)
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diff --git a/target/s390x/tcg/cc_helper.c b/target/s390x/tcg/cc_helper.c
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index 8d04097f78..e11cdb745d 100644
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--- a/target/s390x/tcg/cc_helper.c
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+++ b/target/s390x/tcg/cc_helper.c
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@@ -136,7 +136,7 @@ static uint32_t cc_calc_subu(uint64_t borrow_out, uint64_t result)
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static uint32_t cc_calc_add_64(int64_t a1, int64_t a2, int64_t ar)
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{
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- if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar > 0)) {
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+ if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar >= 0)) {
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return 3; /* overflow */
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} else {
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if (ar < 0) {
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@@ -196,7 +196,7 @@ static uint32_t cc_calc_comp_64(int64_t dst)
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static uint32_t cc_calc_add_32(int32_t a1, int32_t a2, int32_t ar)
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{
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- if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar > 0)) {
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+ if ((a1 > 0 && a2 > 0 && ar < 0) || (a1 < 0 && a2 < 0 && ar >= 0)) {
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return 3; /* overflow */
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} else {
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if (ar < 0) {
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--
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2.37.3
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