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Simplify unsigned integer divisions.

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This commit is contained in:
Maxim Poliakovski 2020-02-10 17:16:18 +01:00
parent a06fb88324
commit a72e2fd67d
1 changed files with 19 additions and 49 deletions
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68
cpu/ppc/ppcopcodes.cpp
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@ -182,15 +182,6 @@ inline void ppc_setsoov(uint32_t a, uint32_t b, uint32_t d) {
}
}
inline void ppc_setsoov_divwo(uint32_t a, uint32_t d) {
if (d > a) {
ppc_state.ppc_spr[SPR::XER] |= 0xC0000000UL;
}
else {
ppc_state.ppc_spr[SPR::XER] &= 0xBFFFFFFFUL;
}
}
/**
The core functionality of this PPC emulation is within all of these void functions.
This is where the opcode tables in the ppcemumain.h come into play - reducing the number of comparisons needed.
@ -986,73 +977,52 @@ void ppc_divwodot() {
void ppc_divwu() {
ppc_grab_regsdab();
//handle division by zero cases
switch (ppc_result_b) {
case 0:
if (!ppc_result_b) { /* division by zero */
ppc_result_d = 0;
ppc_store_result_regd();
return;
default:
uidiv_result = ppc_result_a / ppc_result_b;
ppc_result_d = uidiv_result;
ppc_store_result_regd();
} else {
ppc_result_d = ppc_result_a / ppc_result_b;
}
ppc_store_result_regd();
}
void ppc_divwudot() {
ppc_grab_regsdab();
//handle division by zero cases
switch (ppc_result_b) {
case 0:
if (!ppc_result_b) { /* division by zero */
ppc_result_d = 0;
ppc_store_result_regd();
ppc_state.ppc_cr |= 0x20000000;
return;
default:
uidiv_result = ppc_result_a / ppc_result_b;
ppc_result_d = uidiv_result;
} else {
ppc_result_d = ppc_result_a / ppc_result_b;
ppc_changecrf0(ppc_result_d);
ppc_store_result_regd();
}
ppc_store_result_regd();
}
void ppc_divwuo() {
ppc_grab_regsdab();
//handle division by zero cases
switch (ppc_result_b) {
case 0:
if (!ppc_result_b) { /* division by zero */
ppc_result_d = 0;
ppc_state.ppc_spr[SPR::XER] |= 0xC0000000;
ppc_store_result_regd();
return;
default:
uidiv_result = ppc_result_a / ppc_result_b;
ppc_result_d = uidiv_result;
ppc_setsoov_divwo(ppc_result_a, ppc_result_d);
ppc_store_result_regd();
} else {
ppc_result_d = ppc_result_a / ppc_result_b;
ppc_state.ppc_spr[SPR::XER] &= 0xBFFFFFFFUL;
}
ppc_store_result_regd();
}
void ppc_divwuodot() {
ppc_grab_regsdab();
//handle division by zero cases
switch (ppc_result_b) {
case 0:
if (!ppc_result_b) { /* division by zero */
ppc_result_d = 0;
ppc_store_result_regd();
ppc_state.ppc_spr[SPR::XER] |= 0xC0000000;
ppc_state.ppc_cr |= 0x30000000;
return;
default:
uidiv_result = ppc_result_a / ppc_result_b;
ppc_result_d = uidiv_result;
ppc_setsoov_divwo(ppc_result_a, ppc_result_d);
ppc_changecrf0(ppc_result_d);
ppc_store_result_regd();
} else {
ppc_result_d = ppc_result_a / ppc_result_b;
ppc_state.ppc_spr[SPR::XER] &= 0xBFFFFFFFUL;
}
ppc_changecrf0(ppc_result_d);
ppc_store_result_regd();
}
//Value shifting