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ppcmmu: invert BAT mask to speed up match.

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This commit is contained in:
Maxim Poliakovski 2021-04-11 02:03:20 +02:00
parent d545780071
commit 0375b6a687
2 changed files with 15 additions and 15 deletions
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28
cpu/ppc/ppcmmu.cpp
View File

@ -130,7 +130,7 @@ void ppc_set_cur_instruction(const uint8_t* ptr) {
void ibat_update(uint32_t bat_reg) {
int upper_reg_num;
uint32_t bl, lo_mask;
uint32_t bl, hi_mask;
PPC_BAT_entry* bat_entry;
upper_reg_num = bat_reg & 0xFFFFFFFE;
@ -138,19 +138,19 @@ void ibat_update(uint32_t bat_reg) {
if (ppc_state.spr[upper_reg_num] & 3) { // is that BAT pair valid?
bat_entry = &ibat_array[(bat_reg - 528) >> 1];
bl = (ppc_state.spr[upper_reg_num] >> 2) & 0x7FF;
lo_mask = (bl << 17) | 0x1FFFF;
hi_mask = ~((bl << 17) | 0x1FFFF);
bat_entry->access = ppc_state.spr[upper_reg_num] & 3;
bat_entry->prot = ppc_state.spr[upper_reg_num + 1] & 3;
bat_entry->lo_mask = lo_mask;
bat_entry->phys_hi = ppc_state.spr[upper_reg_num + 1] & ~lo_mask;
bat_entry->bepi = ppc_state.spr[upper_reg_num] & ~lo_mask;
bat_entry->hi_mask = hi_mask;
bat_entry->phys_hi = ppc_state.spr[upper_reg_num + 1] & hi_mask;
bat_entry->bepi = ppc_state.spr[upper_reg_num] & hi_mask;
}
}
void dbat_update(uint32_t bat_reg) {
int upper_reg_num;
uint32_t bl, lo_mask;
uint32_t bl, hi_mask;
PPC_BAT_entry* bat_entry;
upper_reg_num = bat_reg & 0xFFFFFFFE;
@ -158,13 +158,13 @@ void dbat_update(uint32_t bat_reg) {
if (ppc_state.spr[upper_reg_num] & 3) { // is that BAT pair valid?
bat_entry = &dbat_array[(bat_reg - 536) >> 1];
bl = (ppc_state.spr[upper_reg_num] >> 2) & 0x7FF;
lo_mask = (bl << 17) | 0x1FFFF;
hi_mask = ~((bl << 17) | 0x1FFFF);
bat_entry->access = ppc_state.spr[upper_reg_num] & 3;
bat_entry->prot = ppc_state.spr[upper_reg_num + 1] & 3;
bat_entry->lo_mask = lo_mask;
bat_entry->phys_hi = ppc_state.spr[upper_reg_num + 1] & ~lo_mask;
bat_entry->bepi = ppc_state.spr[upper_reg_num] & ~lo_mask;
bat_entry->hi_mask = hi_mask;
bat_entry->phys_hi = ppc_state.spr[upper_reg_num + 1] & hi_mask;
bat_entry->bepi = ppc_state.spr[upper_reg_num] & hi_mask;
}
}
@ -309,7 +309,7 @@ static uint32_t ppc_mmu_instr_translate(uint32_t la) {
for (int bat_index = 0; bat_index < 4; bat_index++) {
PPC_BAT_entry* bat_entry = &ibat_array[bat_index];
if ((bat_entry->access & access_bits) && ((la & ~bat_entry->lo_mask) == bat_entry->bepi)) {
if ((bat_entry->access & access_bits) && ((la & bat_entry->hi_mask) == bat_entry->bepi)) {
bat_hit = true;
if (!bat_entry->prot) {
@ -317,7 +317,7 @@ static uint32_t ppc_mmu_instr_translate(uint32_t la) {
}
// logical to physical translation
pa = bat_entry->phys_hi | (la & bat_entry->lo_mask);
pa = bat_entry->phys_hi | (la & ~bat_entry->hi_mask);
break;
}
}
@ -349,7 +349,7 @@ static uint32_t ppc_mmu_addr_translate(uint32_t la, int is_write) {
for (int bat_index = 0; bat_index < 4; bat_index++) {
PPC_BAT_entry* bat_entry = &dbat_array[bat_index];
if ((bat_entry->access & access_bits) && ((la & ~bat_entry->lo_mask) == bat_entry->bepi)) {
if ((bat_entry->access & access_bits) && ((la & bat_entry->hi_mask) == bat_entry->bepi)) {
bat_hit = true;
if (!bat_entry->prot || ((bat_entry->prot & 1) && is_write)) {
@ -359,7 +359,7 @@ static uint32_t ppc_mmu_addr_translate(uint32_t la, int is_write) {
}
// logical to physical translation
pa = bat_entry->phys_hi | (la & bat_entry->lo_mask);
pa = bat_entry->phys_hi | (la & ~bat_entry->hi_mask);
break;
}
}

2
cpu/ppc/ppcmmu.h
View File

@ -36,7 +36,7 @@ typedef struct PPC_BAT_entry {
uint8_t access; /* copy of Vs | Vp bits */
uint8_t prot; /* copy of PP bits */
uint32_t phys_hi; /* high-order bits for physical address generation */
uint32_t lo_mask; /* mask for low-order logical address bits */
uint32_t hi_mask; /* mask for high-order logical address bits */
uint32_t bepi; /* copy of Block effective page index */
} PPC_BAT_entry;