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[v2,for-10.0,30/54] target/m68k: In frem helper, initialize local float_status from env->fp_status

Message ID 20241202131347.498124-31-peter.maydell@linaro.org
State Superseded
Headers show
Series fpu: Remove pickNaNMulAdd, default-NaN ifdefs | expand

Commit Message

Peter Maydell Dec. 2, 2024, 1:13 p.m. UTC 
In the frem helper, we have a local float_status because we want to
execute the floatx80_div() with a custom rounding mode.  Instead of
zero-initializing the local float_status and then having to set it up
with the m68k standard behaviour (including the NaN propagation rule
and copying the rounding precision from env->fp_status), initialize
it as a complete copy of env->fp_status. This will avoid our having
to add new code in this function for every new config knob we add
to fp_status.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/m68k/fpu_helper.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

Comments

Richard Henderson Dec. 2, 2024, 5:22 p.m. UTC | #1 
On 12/2/24 07:13, Peter Maydell wrote:
> In the frem helper, we have a local float_status because we want to
> execute the floatx80_div() with a custom rounding mode.  Instead of
> zero-initializing the local float_status and then having to set it up
> with the m68k standard behaviour (including the NaN propagation rule
> and copying the rounding precision from env->fp_status), initialize
> it as a complete copy of env->fp_status. This will avoid our having
> to add new code in this function for every new config knob we add
> to fp_status.
> 
> Signed-off-by: Peter Maydell<peter.maydell@linaro.org>
> ---
>   target/m68k/fpu_helper.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)

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

r~
diff mbox series

Patch

diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c
index a605162b71f..e3f4a188501 100644
--- a/target/m68k/fpu_helper.c
+++ b/target/m68k/fpu_helper.c
@@ -615,15 +615,13 @@  void HELPER(frem)(CPUM68KState *env, FPReg *res, FPReg *val0, FPReg *val1)
 
     fp_rem = floatx80_rem(val1->d, val0->d, &env->fp_status);
     if (!floatx80_is_any_nan(fp_rem)) {
-        float_status fp_status = { };
+        /* Use local temporary fp_status to set different rounding mode */
+        float_status fp_status = env->fp_status;
         uint32_t quotient;
         int sign;
 
         /* Calculate quotient directly using round to nearest mode */
-        set_float_2nan_prop_rule(float_2nan_prop_ab, &fp_status);
         set_float_rounding_mode(float_round_nearest_even, &fp_status);
-        set_floatx80_rounding_precision(
-            get_floatx80_rounding_precision(&env->fp_status), &fp_status);
         fp_quot.d = floatx80_div(val1->d, val0->d, &fp_status);
 
         sign = extractFloatx80Sign(fp_quot.d);