From: tg@gmplib.org (Torbjörn Granlund)
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] Bug in s390 instruction emulation
Date: Wed, 03 Dec 2014 22:16:37 +0100 [thread overview]
Message-ID: <86lhmo303u.fsf@shell.gmplib.org> (raw)
The s390 instruction emulation makes GMP fail most of its tests.
I have isolated one of the problems:
How to reproduce:
gcc m.c x.s
./a.out
Correct output on actual hardware:
ffffffff
Incorrect output using QEMU 2.2.0 rc4:
0
File m.c:
#include <stdio.h>
int foo();
int main() { printf("%x\n", foo()); return 0; }
File x.s:
.text
.align 8
.globl foo
.type foo,@function
foo: lghi %r2, 0
lghi %r3, 1
slgr %r2, %r3
slbgr %r3, %r3
slbgr %r2, %r2
br %r14
(This is using "user mode" emulation. System mode emulation doesn't
work at all, and never did, as I am sure you know. I suppose getting
basic instruction emulation correct is a good first step.)
--
Torbjörn
Please encrypt, key id 0xC8601622
next reply other threads:[~2014-12-03 21:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-03 21:16 Torbjörn Granlund [this message]
2014-12-13 22:10 ` [Qemu-devel] Bug in s390 instruction emulation Torbjörn Granlund
2014-12-14 21:45 ` Paolo Bonzini
2014-12-15 23:44 ` Torbjörn Granlund
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