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[Qemu-devel] Emulation differences, qemu-system-x86_64 vs Athlon64
From: |
Julian Seward |
Subject: |
[Qemu-devel] Emulation differences, qemu-system-x86_64 vs Athlon64 |
Date: |
Wed, 12 Apr 2006 13:08:00 +0100 |
User-agent: |
KMail/1.8.2 |
Recently I've been playing with CVS qemu-system (softmmu) on amd64
and had some stability problems. I decided to run Valgrind's amd64
instruction-set tests (derived from qemu's) to see if they picked up
anything. Resulting diffs are attached.
There are a bunch of differences for the C flag for rotates
(rol/ror) by multiples of the word size. I don't think these
are significant, but who knows.
Perhaps more worryingly are the 20 or so lines at the bottom
of the diff. These I believe are for double-to-int/short
conversions for a value which is out of range for an int/short;
the hardware produces 0x80000000/0x8000 respectively, which is
the "integer indefinite"; QEMU produces zero. I can imagine some
obscure routine somewhere checking for integer indefinite after
conversion and being confused as a result.
J
diffs-qemu-vs-Athlon64.txt.bz2
Description: BZip2 compressed data
- [Qemu-devel] Emulation differences, qemu-system-x86_64 vs Athlon64,
Julian Seward <=