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target/arm: arm_reset_sve_state() should set FPSR, not FPCR

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The pseudocode ResetSVEState() does:
    FPSR = ZeroExtend(0x0800009f<31:0>, 64);
but QEMU's arm_reset_sve_state() called vfp_set_fpcr() by accident.

Before the advent of FEAT_AFP, this was only setting a collection of
RES0 bits, which vfp_set_fpsr() would then ignore, so the only effect
was that we didn't actually set the FPSR the way we are supposed to
do.  Once FEAT_AFP is implemented, setting the bottom bits of FPSR
will change the floating point behaviour.

Call vfp_set_fpsr(), as we ought to.

(Note for stable backports: commit 7f2a01e7368f9 moved this function
from sme_helper.c to helper.c, but it had the same bug before the
move too.)

Cc: qemu-stable@nongnu.org
Fixes: f84734b87461 ("target/arm: Implement SMSTART, SMSTOP")
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20250124162836.2332150-4-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2025-01-24 16:27:23 +00:00
parent cb5f6ca8af
commit 1edc3d43f2
1 changed files with 1 additions and 1 deletions
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2
target/arm/helper.c
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@ -6413,7 +6413,7 @@ static void arm_reset_sve_state(CPUARMState *env)
memset(env->vfp.zregs, 0, sizeof(env->vfp.zregs)); memset(env->vfp.zregs, 0, sizeof(env->vfp.zregs));
/* Recall that FFR is stored as pregs[16]. */ /* Recall that FFR is stored as pregs[16]. */
memset(env->vfp.pregs, 0, sizeof(env->vfp.pregs)); memset(env->vfp.pregs, 0, sizeof(env->vfp.pregs));
vfp_set_fpcr(env, 0x0800009f); vfp_set_fpsr(env, 0x0800009f);
} }
void aarch64_set_svcr(CPUARMState *env, uint64_t new, uint64_t mask) void aarch64_set_svcr(CPUARMState *env, uint64_t new, uint64_t mask)