[v2,15/27] target/arm: Fix fp_status_f16 tininess before rounding

Message ID 20180512004311.9299-16-richard.henderson@linaro.org
State New
Headers show
Series
  • softfloat patch roundup
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Commit Message

Richard Henderson May 12, 2018, 12:42 a.m.
From: Peter Maydell <peter.maydell@linaro.org>


In commit d81ce0ef2c4f105 we added an extra float_status field
fp_status_fp16 for Arm, but forgot to initialize it correctly
by setting it to float_tininess_before_rounding. This currently
will only cause problems for the new V8_FP16 feature, since the
float-to-float conversion code doesn't use it yet. The effect
would be that we failed to set the Underflow IEEE exception flag
in all the cases where we should.

Add the missing initialization.

Fixes: d81ce0ef2c4f105
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 target/arm/cpu.c | 2 ++
 1 file changed, 2 insertions(+)

-- 
2.17.0

Comments

Peter Maydell May 14, 2018, 1:59 p.m. | #1
On 12 May 2018 at 01:42, Richard Henderson <richard.henderson@linaro.org> wrote:
> From: Peter Maydell <peter.maydell@linaro.org>

>

> In commit d81ce0ef2c4f105 we added an extra float_status field

> fp_status_fp16 for Arm, but forgot to initialize it correctly

> by setting it to float_tininess_before_rounding. This currently

> will only cause problems for the new V8_FP16 feature, since the

> float-to-float conversion code doesn't use it yet. The effect

> would be that we failed to set the Underflow IEEE exception flag

> in all the cases where we should.

>

> Add the missing initialization.

>

> Fixes: d81ce0ef2c4f105

> Cc: qemu-stable@nongnu.org

> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>


NB that there are reviewed-by: tags from you and Alex that need
to be added to this commit message.

Thanks for fixing up the subject line for me.

thanks
-- PMM

Patch

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index d175c5e94f..7939c6b8ae 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -324,6 +324,8 @@  static void arm_cpu_reset(CPUState *s)
                               &env->vfp.fp_status);
     set_float_detect_tininess(float_tininess_before_rounding,
                               &env->vfp.standard_fp_status);
+    set_float_detect_tininess(float_tininess_before_rounding,
+                              &env->vfp.fp_status_f16);
 #ifndef CONFIG_USER_ONLY
     if (kvm_enabled()) {
         kvm_arm_reset_vcpu(cpu);