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dingusppc
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Refactor recent subfme fix.

This commit is contained in:
Maxim Poliakovski 2023-12-24 02:35:38 +01:00
parent dc00879419
commit fef5bde0c7
1 changed files with 13 additions and 14 deletions
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27
cpu/ppc/ppcopcodes.cpp
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@ -1,6 +1,6 @@
/*
DingusPPC - The Experimental PowerPC Macintosh emulator
Copyright (C) 2018-21 divingkatae and maximum
Copyright (C) 2018-23 divingkatae and maximum
(theweirdo) spatium
(Contact divingkatae#1017 or powermax#2286 on Discord for more info)
@ -362,20 +362,19 @@ void dppc_interpreter::ppc_subfe() {
void dppc_interpreter::ppc_subfme() {
ppc_grab_regsda();
uint32_t grab_xer = !!(ppc_state.spr[SPR::XER] & 0x20000000);
ppc_result_d = ~ppc_result_a + grab_xer - 1;
uint32_t grab_ca = !!(ppc_state.spr[SPR::XER] & XER::CA);
ppc_result_d = ~ppc_result_a + grab_ca - 1;
if (ppc_result_d == ppc_result_a) {
// this only occurs when CA is 0 and ppc_result_a is 0x7fffffff or 0xffffffff
if ((int32_t)ppc_result_d > 0) {
ppc_state.spr[SPR::XER] |= oe_flag ? 0xE0000000UL : 0x20000000UL; // set SO,OV,CA
} else {
ppc_state.spr[SPR::XER] &= oe_flag ? ~0x60000000UL : ~0x20000000UL; // clear OV,CA
}
} else {
ppc_state.spr[SPR::XER] |= 0x20000000UL; // set CA
if (oe_flag)
ppc_state.spr[SPR::XER] &= ~0x40000000UL; // clear OV
if (ppc_result_a == 0xFFFFFFFFUL && !grab_ca)
ppc_state.spr[SPR::XER] &= ~XER::CA;
else
ppc_state.spr[SPR::XER] |= XER::CA;
if (oe_flag) {
if (ppc_result_d == ppc_result_a && (int32_t)ppc_result_d > 0)
ppc_state.spr[SPR::XER] |= XER::SO | XER::OV;
else
ppc_state.spr[SPR::XER] &= ~XER::OV;
}
if (rc_flag)