[Qemu-devel] Bug in s390 instruction emulation

[tg@gmplib.org (Torbjörn Granlund)]

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