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Remove COMPLETED_FRAME flag to simplify things

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This commit is contained in:
David Guillen Fandos 2023-09-06 00:48:37 +02:00
parent 5f3e0a88cf
commit 1d1c719372
9 changed files with 53 additions and 51 deletions
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10
arm/arm64_stub.S
View file

@ -57,7 +57,7 @@ _##symbol:
#define REG_Z_FLAG (21 * 4)
#define REG_C_FLAG (22 * 4)
#define REG_V_FLAG (23 * 4)
#define COMPLETED_FRAME (24 * 4)
#define REG_UNUSED_1 (24 * 4)
#define OAM_UPDATED (25 * 4)
#define REG_SAVE (26 * 4)
@ -153,14 +153,13 @@ defsymbl(a64_update_gba)
mov w0, reg_cycles // load remaining cycles
bl update_gba // update GBA state
ldr w1, [reg_base, #COMPLETED_FRAME] // return to main if new frame
cbnz w1, return_to_main
tbnz w0, #31, return_to_main // exit if a new frame is ready
// Resume execution (perhaps from a new PC)
and reg_cycles, w0, 0x7fff // load new cycle count
extract_flags(w2) // reload flag cache bits
tbnz w0, #31, 1f // check if PC changed
tbnz w0, #30, 1f // check if PC changed
ldr lr, [reg_base, #REG_SAVE] // Restore return point
load_registers() // reload registers
@ -714,8 +713,7 @@ cpu_sleep_loop:
mov w0, reg_cycles // load remaining cycles
bl update_gba // update GBA until CPU isn't halted
ldr w1, [reg_base, #COMPLETED_FRAME] // Check whether a frame was completed
cbnz w1, return_to_main // and return to caller function.
tbnz w0, #31, return_to_main // a frame has been completed -> exit
// At this point the CPU must be active, otherwise we sping in update_gba

19
arm/arm_stub.S
View file

@ -39,7 +39,7 @@ _##symbol:
#define REG_Z_FLAG (21 * 4)
#define REG_C_FLAG (22 * 4)
#define REG_V_FLAG (23 * 4)
#define COMPLETED_FRAME (24 * 4)
#define REG_UNUSED_1 (24 * 4)
#define OAM_UPDATED (25 * 4)
#define CPU_ALERT_HALT (1 << 0)
@ -195,14 +195,13 @@ defsymbl(arm_update_gba_##name) ;\
cycles_##return_op() /* remaining cycles in arg0 */;\
call_c_function(update_gba) /* update GBA state */;\
;\
ldr r1, [reg_base, #COMPLETED_FRAME] /* return if new frame */;\
cmp r1, #0 ;\
bne return_to_main ;\
cmp r0, #0 /* check MSB for frame completion*/;\
blt return_to_main ;\
;\
bic reg_cycles, r0, #0x80000000 /* clear MSB, not part of count */;\
bic reg_cycles, r0, #0xF0000000 /* clear MSB, not part of count */;\
mvn reg_cycles, reg_cycles /* we count negative to zero */;\
;\
tst r0, #0x80000000 /* set if PC changed */;\
tst r0, #0x40000000 /* set if PC changed */;\
bne 1f /* go jump/translate */;\
;\
load_registers_##mode() /* reload registers */;\
@ -698,11 +697,11 @@ write_epilogue:
cpu_sleep_loop:
call_c_function(update_gba) @ update GBA until CPU isn't halted
bic r0, r0, #0x80000000 @ clear MSB, not part of count
ldr r1, [reg_base, #COMPLETED_FRAME] @ Check whether a frame was completed
cmp r1, #0
bne return_to_main
cmp r0, #0
blt return_to_main @ New frame if bit 31 is set. Exit
bic r0, r0, #0xF0000000 @ clear MSB, not part of count
@ The cpu is active again, go ahead and resume execution at current PC
mvn reg_cycles, r0 @ load new cycle count

22
cpu.c
View file

@ -1535,6 +1535,7 @@ void execute_arm(u32 cycles)
u8 *pc_address_block = memory_map_read[pc_region];
u32 new_pc_region;
s32 cycles_remaining;
u32 update_ret;
cpu_alert_type cpu_alert;
u32 old_pc;
@ -1549,11 +1550,12 @@ void execute_arm(u32 cycles)
while(1)
{
/* Do not execute until CPU is active */
while(reg[CPU_HALT_STATE] != CPU_ACTIVE) {
cycles_remaining = update_gba_cycles(cycles_remaining);
if (reg[COMPLETED_FRAME])
if (reg[CPU_HALT_STATE] != CPU_ACTIVE) {
u32 ret = update_gba(cycles_remaining);
if (completed_frame(ret))
return;
cycles_remaining = cycles_to_run(ret);
}
cpu_alert = CPU_ALERT_NONE;
@ -3146,9 +3148,10 @@ skip_instruction:
} while(cycles_remaining > 0);
collapse_flags();
cycles_remaining = update_gba_cycles(cycles_remaining);
if (reg[COMPLETED_FRAME])
update_ret = update_gba(cycles_remaining);
if (completed_frame(update_ret))
return;
cycles_remaining = cycles_to_run(update_ret);
continue;
do
@ -3665,9 +3668,10 @@ thumb_loop:
} while(cycles_remaining > 0);
collapse_flags();
cycles_remaining = update_gba_cycles(cycles_remaining);
if (reg[COMPLETED_FRAME])
return;
update_ret = update_gba(cycles_remaining);
if (completed_frame(update_ret))
return;
cycles_remaining = cycles_to_run(update_ret);
continue;
alert:

2
cpu.h
View file

@ -91,7 +91,7 @@ typedef enum
REG_Z_FLAG = 21,
REG_C_FLAG = 22,
REG_V_FLAG = 23,
COMPLETED_FRAME = 24,
REG_UNUSED_1 = 24,
OAM_UPDATED = 25,
REG_SAVE = 26,
REG_SAVE2 = 27,

10
main.c
View file

@ -107,6 +107,7 @@ void init_main(void)
u32 function_cc update_gba(int remaining_cycles)
{
u32 changed_pc = 0;
u32 frame_complete = 0;
irq_type irq_raised = IRQ_NONE;
int dma_cycles;
trace_update_gba(remaining_cycles);
@ -122,7 +123,6 @@ u32 function_cc update_gba(int remaining_cycles)
cpu_ticks += completed_cycles;
remaining_cycles = 0;
reg[COMPLETED_FRAME] = 0;
// Timers can trigger DMA (usually sound) and consume cycles
dma_cycles = update_timers(&irq_raised, completed_cycles);
@ -217,7 +217,7 @@ u32 function_cc update_gba(int remaining_cycles)
render_gbc_sound();
// We completed a frame, tell the dynarec to exit to the main thread
reg[COMPLETED_FRAME] = 1;
frame_complete = 0x80000000;
}
// Vcount trigger (flag) and IRQ if enabled
@ -241,7 +241,7 @@ u32 function_cc update_gba(int remaining_cycles)
// Raise any pending interrupts. This changes the CPU mode.
if (check_and_raise_interrupts())
changed_pc = 0x80000000;
changed_pc = 0x40000000;
// Figure out when we need to stop CPU execution. The next event is
// a video event or a timer event, whatever happens first.
@ -253,13 +253,13 @@ u32 function_cc update_gba(int remaining_cycles)
timer[i].count < execute_cycles)
execute_cycles = timer[i].count;
}
} while(reg[CPU_HALT_STATE] != CPU_ACTIVE && !reg[COMPLETED_FRAME]);
} while(reg[CPU_HALT_STATE] != CPU_ACTIVE && !frame_complete);
// We voluntarily limit this. It is not accurate but it would be much harder.
dma_cycles = MIN(64, dma_cycles);
dma_cycles = MIN(execute_cycles, dma_cycles);
return (execute_cycles - dma_cycles) | changed_pc;
return (execute_cycles - dma_cycles) | changed_pc | frame_complete;
}
void reset_gba(void)

3
main.h
View file

@ -77,7 +77,8 @@ extern u32 flush_ram_count;
extern char main_path[512];
extern char save_path[512];
#define update_gba_cycles(c) (update_gba(c) & 0x7FFF)
#define cycles_to_run(c) ((c) & 0x7FFF)
#define completed_frame(c) ((c) & 0x80000000)
u32 function_cc update_gba(int remaining_cycles);
void reset_gba(void);

11
mips/mips_stub.S
View file

@ -104,7 +104,7 @@ symbol:
.equ REG_Z_FLAG, (21 * 4)
.equ REG_C_FLAG, (22 * 4)
.equ REG_V_FLAG, (23 * 4)
.equ COMPLETED_FRAME, (24 * 4)
.equ REG_UNUSED_1, (24 * 4)
.equ OAM_UPDATED, (25 * 4)
.equ REG_SAVE, (26 * 4)
.equ REG_SAVE2, (27 * 4)
@ -248,12 +248,12 @@ defsymbl(mips_update_gba)
move $4, reg_cycles # Remaining cycles as asg0
cfncall update_gba, 0 # process the next event
lw $1, COMPLETED_FRAME($16) # Check whether we completed a frame
bne $1, $0, return_to_main # Return to main thread now
bltz $2, return_to_main # Exit if a frame is complete (bit 31 is set)
and reg_cycles, $2, 0x7FFF # update new cycle count (ret value)
bltz $2, lookup_pc
sll $1, $2, 1 # Check bit 30 now (PC changed)
bltz $1, lookup_pc
lw $ra, REG_SAVE2($16) # restore return address
restore_registers
@ -344,8 +344,7 @@ cpu_sleep_loop:
move $4, reg_cycles # Remaining cycles as asg0
cfncall update_gba, 0 # process the next event
lw $1, COMPLETED_FRAME($16) # Check whether we completed a frame
bne $1, $0, return_to_main # Return to main thread now
bltz $2, return_to_main # Exit if a frame is complete (bit 31 is set)
# since no frame was completed, this means CPU is active again.
# Fall through to lookup_pc to resume execution

1
savestate.c
View file

@ -107,7 +107,6 @@ bool gba_load_state(const void* src)
#endif
instruction_count = 0;
reg[COMPLETED_FRAME] = 0;
reg[OAM_UPDATED] = 1;
return true;

26
x86/x86_stub.S
View file

@ -95,7 +95,7 @@ _##symbol:
.equ REG_Z_FLAG, (21 * 4)
.equ REG_C_FLAG, (22 * 4)
.equ REG_V_FLAG, (23 * 4)
.equ COMPLETED_FRAME, (24 * 4)
.equ REG_UNUSED_1, (24 * 4)
.equ OAM_UPDATED, (25 * 4)
.equ REG_SAVE, (26 * 4)
@ -170,17 +170,19 @@ defsymbl(x86_update_gba)
mov REG_CYCLES, CARG1_REG # Load remaining cycles as arg0
CALL_FUNC(update_gba) # process the next event
# did we just complete a frame? go back to main then
test %eax, %eax # Bit 31 set, means new frame completed
js return_to_main
# Load new cycle counter
mov %eax, REG_CYCLES # new cycle count
and $0x7fff, REG_CYCLES # in the lowest bits
# did we just complete a frame? go back to main then
cmpl $0, COMPLETED_FRAME(REG_BASE)
jne return_to_main
# did the PC change?
test %eax, %eax # Bit 31 set, means need to re-fetch
js lookup_pc
ret # otherwise, go back to caller
# did the PC change? Bit 30 will be set
test $0x40000000, %eax
jne lookup_pc
ret # otherwise, go back to caller (resume)
# Perform this on an indirect branch that will definitely go to
# ARM code, IE anything that changes the PC in ARM mode except
@ -265,9 +267,9 @@ cpu_sleep_loop:
mov REG_CYCLES, CARG1_REG # Load remaining cycles as arg0
CALL_FUNC(update_gba) # process the next event
# did we just complete a frame? go back to main then
cmpl $0, COMPLETED_FRAME(REG_BASE)
jne return_to_main
# did we just complete a frame (MSB set)? go back to main then
test %eax, %eax
js return_to_main
// if we are out of update_gba and did not complete a frame, cpu is active
mov %eax, REG_CYCLES # load new cycle count