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Created address translation fast path for code reads, separated slow path into separate function so the fast path is more likely to be inlined. 10-20% performance improvement

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This commit is contained in:
Rune Holm
2021-06-11 18:37:57 +01:00
parent c7d20e9a17
commit 3203ac8590
3 changed files with 83 additions and 45 deletions
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2
emulator.c
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@@ -4,6 +4,7 @@
#include "emulator.h"
#include "platforms/platforms.h"
#include "input/input.h"
#include "m68kcpu.h"
#include "platforms/amiga/Gayle.h"
#include "platforms/amiga/amiga-registers.h"
@@ -43,6 +44,7 @@ unsigned char write_ranges;
unsigned int write_addr[8];
unsigned int write_upper[8];
unsigned char *write_data[8];
address_translation_cache code_translation_cache = {0};
int kb_hook_enabled = 0;
int mouse_hook_enabled = 0;

63
m68kcpu.c
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@@ -1208,7 +1208,7 @@ inline unsigned int m68k_read_immediate_16(unsigned int address) {
}
}
#endif
return m68k_read_memory_16(address);
}
inline unsigned int m68k_read_immediate_32(unsigned int address) {
@@ -1230,7 +1230,7 @@ inline unsigned int m68k_read_pcrelative_8(unsigned int address) {
return read_data[i][address - read_addr[i]];
}
}
return m68k_read_memory_8(address);
}
inline unsigned int m68k_read_pcrelative_16(unsigned int address) {
@@ -1253,8 +1253,65 @@ inline unsigned int m68k_read_pcrelative_32(unsigned int address) {
}
#endif
uint m68ki_read_imm6_addr_slowpath(uint32_t address, address_translation_cache *cache)
{
for (int i = 0; i < read_ranges; i++) {
if(address >= read_addr[i] && address < read_upper[i]) {
cache->lower = read_addr[i];
cache->upper = read_upper[i];
cache->data = read_data[i];
REG_PC += 2;
return be16toh(((unsigned short *)(read_data[i] + (address - read_addr[i])))[0]);
}
}
m68ki_set_fc(FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */
m68ki_cpu.mmu_tmp_fc = FLAG_S | FUNCTION_CODE_USER_PROGRAM;
m68ki_cpu.mmu_tmp_rw = 1;
m68ki_cpu.mmu_tmp_sz = M68K_SZ_WORD;
m68ki_check_address_error(REG_PC, MODE_READ, FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */
#if M68K_EMULATE_PREFETCH
{
uint result;
if(REG_PC != CPU_PREF_ADDR)
{
CPU_PREF_DATA = m68ki_ic_readimm16(REG_PC);
CPU_PREF_ADDR = m68ki_cpu.mmu_tmp_buserror_occurred ? ((uint32)~0) : REG_PC;
}
result = MASK_OUT_ABOVE_16(CPU_PREF_DATA);
REG_PC += 2;
if (!m68ki_cpu.mmu_tmp_buserror_occurred) {
// prefetch only if no bus error occurred in opcode fetch
CPU_PREF_DATA = m68ki_ic_readimm16(REG_PC);
CPU_PREF_ADDR = m68ki_cpu.mmu_tmp_buserror_occurred ? ((uint32)~0) : REG_PC;
// ignore bus error on prefetch
m68ki_cpu.mmu_tmp_buserror_occurred = 0;
}
return result;
}
#else
uint32_t address = ADDRESS_68K(REG_PC);
REG_PC += 2;
for (int i = 0; i < read_ranges; i++) {
if(address >= read_addr[i] && address < read_upper[i]) {
return be16toh(((unsigned short *)(read_data[i] + (address - read_addr[i])))[0]);
}
}
return m68k_read_immediate_16(address);
#endif /* M68K_EMULATE_PREFETCH */
}
void m68k_add_ram_range(uint32_t addr, uint32_t upper, unsigned char *ptr)
{
code_translation_cache.lower = 0;
code_translation_cache.upper = 0;
if ((addr == 0 && upper == 0) || upper < addr)
return;
@@ -1300,6 +1357,8 @@ void m68k_add_ram_range(uint32_t addr, uint32_t upper, unsigned char *ptr)
void m68k_add_rom_range(uint32_t addr, uint32_t upper, unsigned char *ptr)
{
code_translation_cache.lower = 0;
code_translation_cache.upper = 0;
if ((addr == 0 && upper == 0) || upper < addr)
return;

63
m68kcpu.h
View File

@@ -1075,6 +1075,13 @@ char* m68ki_disassemble_quick(unsigned int pc, unsigned int cpu_type);
/* ---------------------------- Read Immediate ---------------------------- */
typedef struct
{
unsigned int lower;
unsigned int upper;
unsigned char *data;
} address_translation_cache;
extern unsigned char read_ranges;
extern unsigned int read_addr[8];
@@ -1085,6 +1092,8 @@ extern unsigned int write_addr[8];
extern unsigned int write_upper[8];
extern unsigned char *write_data[8];
extern address_translation_cache code_translation_cache;
// clear the instruction cache
inline void m68ki_ic_clear()
{
@@ -1152,55 +1161,23 @@ static inline uint32 m68ki_ic_readimm16(uint32 address)
/* Handles all immediate reads, does address error check, function code setting,
* and prefetching if they are enabled in m68kconf.h
*/
uint m68ki_read_imm6_addr_slowpath(uint32_t address, address_translation_cache *cache);
static inline uint m68ki_read_imm_16(void)
{
uint32_t address = ADDRESS_68K(REG_PC);
for (int i = 0; i < read_ranges; i++) {
if(address >= read_addr[i] && address < read_upper[i]) {
REG_PC += 2;
return be16toh(((unsigned short *)(read_data[i] + (address - read_addr[i])))[0]);
}
}
m68ki_set_fc(FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */
m68ki_cpu.mmu_tmp_fc = FLAG_S | FUNCTION_CODE_USER_PROGRAM;
m68ki_cpu.mmu_tmp_rw = 1;
m68ki_cpu.mmu_tmp_sz = M68K_SZ_WORD;
m68ki_check_address_error(REG_PC, MODE_READ, FLAG_S | FUNCTION_CODE_USER_PROGRAM); /* auto-disable (see m68kcpu.h) */
#if M68K_EMULATE_PREFETCH
{
uint result;
if(REG_PC != CPU_PREF_ADDR)
{
CPU_PREF_DATA = m68ki_ic_readimm16(REG_PC);
CPU_PREF_ADDR = m68ki_cpu.mmu_tmp_buserror_occurred ? ((uint32)~0) : REG_PC;
}
result = MASK_OUT_ABOVE_16(CPU_PREF_DATA);
REG_PC += 2;
if (!m68ki_cpu.mmu_tmp_buserror_occurred) {
// prefetch only if no bus error occurred in opcode fetch
CPU_PREF_DATA = m68ki_ic_readimm16(REG_PC);
CPU_PREF_ADDR = m68ki_cpu.mmu_tmp_buserror_occurred ? ((uint32)~0) : REG_PC;
// ignore bus error on prefetch
m68ki_cpu.mmu_tmp_buserror_occurred = 0;
}
return result;
address_translation_cache *cache = &code_translation_cache;
if(address >= cache->lower && address < cache->upper)
{
REG_PC += 2;
return be16toh(((unsigned short *)(cache->data + (address - cache->lower)))[0]);
}
return m68ki_read_imm6_addr_slowpath(address, cache);
}
#else
uint32_t address = ADDRESS_68K(REG_PC);
REG_PC += 2;
for (int i = 0; i < read_ranges; i++) {
if(address >= read_addr[i] && address < read_upper[i]) {
return be16toh(((unsigned short *)(read_data[i] + (address - read_addr[i])))[0]);
}
}
return m68k_read_immediate_16(address);
#endif /* M68K_EMULATE_PREFETCH */
}
static inline uint m68ki_read_imm_8(void)
{