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[Qemu-devel] i386: SSE 4 implementation does not match bare metal
From: |
Florian Weimer |
Subject: |
[Qemu-devel] i386: SSE 4 implementation does not match bare metal |
Date: |
Mon, 12 Oct 2015 10:21:57 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 |
We received a bug report that the SSE-4.2-based strstr in glibc 2.17 was
misbehaving and returned NULL for certain inputs, even though the search
pattern is clearly present in the subject string. I'm attaching a test
case. You can run it as "./tst-strstr 3" to directly go to one failing
case.
I'm not sure how to debug this further, except by running the program
under GDB, single-step through it, dump registers, and compare the
results with a bare-metal implement after each instruction executed.
Downstream bug: https://bugzilla.redhat.com/show_bug.cgi?id=1270703
There is also an attachment with a pre-compiled binary.
Thanks,
Florian
tst-strstr.c
Description: Text Data
- [Qemu-devel] i386: SSE 4 implementation does not match bare metal,
Florian Weimer <=