Re: [PATCH] tcg/s390x: fix constraint for 32-bit TSTEQ/TSTNE

[Paolo Bonzini]

On 10/17/24 12:00, Peter Maydell wrote:
On Thu, 17 Oct 2024 at 10:14, Paolo Bonzini <pbonz...@redhat.com> wrote:

32-bit TSTEQ and TSTNE is subject to the same constraints as
for 64-bit, but setcond_i32 and negsetcond_i32 were incorrectly
using TCG_CT_CONST ("i") instead of TCG_CT_CONST_CMP ("C").

Adjust the constraint and make tcg_target_const_match use the
same sequence as tgen_cmp2: first check if the constant is a
valid operand for TSTEQ/TSTNE, then accept everything for 32-bit
non-test comparisons, finally check if the constant is a valid
operand for 64-bit non-test comparisons.

Reported-by: Philippe Mathieu-Daudé <phi...@linaro.org>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>

Should this cc stable? Does it cause any current problems?
(AIUI the x86 target changes in your pending pullreq do
trigger this.)

Yeah, that's a good idea.  It's probably possible to construct x86 code 
that triggers it (I'm surprised it wasn't found until now).

Paolo