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
This commit is contained in:
Peter Maydell 2024-12-11 15:31:02 +00:00
parent a0c4297738
commit b1969a5dd4

View File

@ -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); fp_rem = floatx80_rem(val1->d, val0->d, &env->fp_status);
if (!floatx80_is_any_nan(fp_rem)) { 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; uint32_t quotient;
int sign; int sign;
/* Calculate quotient directly using round to nearest mode */ /* 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_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); fp_quot.d = floatx80_div(val1->d, val0->d, &fp_status);
sign = extractFloatx80Sign(fp_quot.d); sign = extractFloatx80Sign(fp_quot.d);