From: Peter Maydell <peter.maydell@linaro.org>
Date: Wed, 11 Dec 2024 15:31:02 +0000 (+0000)
Subject: target/m68k: In frem helper, initialize local float_status from env->fp_status
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b1969a5dd4ad72669d739ef6e8caaefb7c7f962c;p=qemu.git

target/m68k: In frem helper, initialize local float_status from env->fp_status

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>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241202131347.498124-31-peter.maydell@linaro.org
---

diff --git a/target/m68k/fpu_helper.c b/target/m68k/fpu_helper.c
index a605162b71..e3f4a18850 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);