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Refactor subfze.

This commit is contained in:
Maxim Poliakovski 2023-12-30 15:58:21 +01:00
parent 1f3505f371
commit 593508df22
1 changed files with 12 additions and 16 deletions
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28
cpu/ppc/ppcopcodes.cpp
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@ -385,23 +385,19 @@ void dppc_interpreter::ppc_subfme() {
void dppc_interpreter::ppc_subfze() {
ppc_grab_regsda();
ppc_result_d = ~ppc_result_a + !!(ppc_state.spr[SPR::XER] & 0x20000000);
uint32_t grab_ca = !!(ppc_state.spr[SPR::XER] & XER::CA);
ppc_result_d = ~ppc_result_a + grab_ca;
if (ppc_result_d == ppc_result_a) {
// this only occurs when CA is 1 and ppc_result_a is 0x00000000 or 0x80000000
if (ppc_result_d == 0) {
ppc_state.spr[SPR::XER] |= 0x20000000UL; // set CA
if (oe_flag)
ppc_state.spr[SPR::XER] &= ~0x40000000UL; // clear OV
} else {
ppc_state.spr[SPR::XER] &= ~0x20000000UL; // clear CA
if (oe_flag)
ppc_state.spr[SPR::XER] |= 0xC0000000UL; // set SO,OV
}
} else {
ppc_state.spr[SPR::XER] &= ~0x20000000UL; // clear CA
if (oe_flag)
ppc_state.spr[SPR::XER] &= ~0x40000000UL; // clear OV
if (!ppc_result_d && grab_ca) // special case: ppc_result_d = 0 and CA=1
ppc_state.spr[SPR::XER] |= XER::CA;
else
ppc_state.spr[SPR::XER] &= ~XER::CA;
if (oe_flag) {
if (ppc_result_d && ppc_result_d == ppc_result_a)
ppc_state.spr[SPR::XER] |= XER::SO | XER::OV;
else
ppc_state.spr[SPR::XER] &= ~XER::OV;
}
if (rc_flag)