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Use of TSTEQ/TSTNE has regressed the cdrom test when running a 32 bit build of qemu-system-x86_64 using TCG
Description of problem:
The test freezes, eventually timing out. The bisect was confused by other SEV related things so I had to whittle down the config to --disable-kvm.
Steps to reproduce:
1. '../../configure' '--disable-docs' '--disable-user' '--cross-prefix=i686-linux-gnu-' '--target-list=x86_64-softmmu' '--enable-debug' '--disable-kvm'
2. ninja
3. meson test -t 0.05 qtest-x86_64/cdrom-test V=1
Additional information:
Bisect run pointed at:
```
commit 15957eb9efe2da67c796612cead95cba28ba9bda
Author: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri Oct 27 05:57:31 2023 +0200
target/i386: use TSTEQ/TSTNE to test low bits
When testing the sign bit or equality to zero of a partial register, it
is useful to use a single TSTEQ or TSTNE operation. It can also be used
to test the parity flag, using bit 0 of the population count.
Do not do this for target_ulong-sized values however; the optimizer would
produce a comparison against zero anyway, and it avoids shifts by 64
which are undefined behavior.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
target/i386/tcg/translate.c | 28 ++++++++++++++++++++--------
target/i386/tcg/emit.c.inc | 5 ++---
2 files changed, 22 insertions(+), 11 deletions(-)
bisect found first bad commit⏎
```
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