On 02/07/2017 11:59 AM, Laurent Vivier wrote:
void HELPER(itrunc_FP0)(CPUM68KState *env)
{
floatx80 res;
+ set_float_rounding_mode(float_round_to_zero, &env->fp_status);
res = floatx80_round_to_int(FP0_to_floatx80(env), &env->fp_status);
+ restore_rounding_mode(env);
It would be better to save/restore the current rounding mode as opposed to
recomputing from the fpcr.
void HELPER(cmp_FP0_FP1)(CPUM68KState *env)
{
floatx80 fp0 = FP0_to_floatx80(env);
floatx80 fp1 = FP1_to_floatx80(env);
- floatx80 res;
+ int float_compare;
- res = floatx80_sub(fp0, fp1, &env->fp_status);
- if (floatx80_is_quiet_nan(res, &env->fp_status)) {
- /* +/-inf compares equal against itself, but sub returns nan. */
- if (!floatx80_is_quiet_nan(fp0, &env->fp_status)
- && !floatx80_is_quiet_nan(fp1, &env->fp_status)) {
- res = floatx80_zero;
- if (floatx80_lt_quiet(fp0, res, &env->fp_status)) {
- res = floatx80_chs(res);
- }
- }
- }
-
- floatx80_to_FP0(env, res);
+ float_compare = floatx80_compare(fp1, fp0, &env->fp_status);
+ env->fpsr = (env->fpsr & ~FPSR_CC_MASK) | float_comp_to_cc(float_compare);
}
-uint32_t HELPER(compare_FP0)(CPUM68KState *env)
+void HELPER(tst_FP0)(CPUM68KState *env)
{
- floatx80 fp0 = FP0_to_floatx80(env);
- return floatx80_compare_quiet(fp0, floatx80_zero, &env->fp_status);
+ uint32_t fpsr = 0;
+ floatx80 val = FP0_to_floatx80(env);
+
+ if (floatx80_is_neg(val)) {
+ fpsr |= FPSR_CC_N;
+ }
+
+ if (floatx80_is_any_nan(val)) {
+ fpsr |= FPSR_CC_A;
+ } else if (floatx80_is_infinity(val)) {
+ fpsr |= FPSR_CC_I;
+ } else if (floatx80_is_zero(val)) {
+ fpsr |= FPSR_CC_Z;
+ }
+ env->fpsr = (env->fpsr & ~FPSR_CC_MASK) | fpsr;
}
It would be better to pass in the old FPSR value, returning the new FPSR value,
so that the helper can be marked TCG_CALL_NO_RWG -- not reading or modifying
TCG globals.
+ gen_helper_tst_FP0(cpu_env);
Making this, e.g. gen_helper_tst_FP0(QREG_FPSR, cpu_env). Which will also
happen to leave the FPSR in a host register where it can be used if the next
insn is a fp branch.
r~
