Retro/pcem
Watch
1
0
Fork
You've already forked pcem
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Added basic loop unrolling. Blocks that end in a JMP, LOOP or conditional branch to a previous instruction in the block will be unrolled up to 10 times.

Browse source
This commit is contained in:
SarahW 2019-03-25 19:07:51 +00:00
commit 7e099c277e
9 changed files with 594 additions and 148 deletions
Download patch file Download diff file Expand all files Collapse all files

45
src/codegen_ops_helpers.c
View file

@ -2,6 +2,7 @@
#include "x86.h"
#include "386_common.h"
#include "codegen.h"
#include "codegen_ir.h"
#include "codegen_ir_defs.h"
#include "codegen_reg.h"
#include "codegen_ops_helpers.h"
@ -24,3 +25,47 @@ void LOAD_IMMEDIATE_FROM_RAM_32_unaligned(codeblock_t *block, ir_data_t *ir, int
uop_SHL_IMM(ir, IREG_temp3, IREG_temp3, (4 - (addr & 3)) * 8);
uop_OR(ir, dest_reg, dest_reg, IREG_temp3);
}
#define UNROLL_MAX_REG_REFERENCES 200
#define UNROLL_MAX_UOPS 1000
#define UNROLL_MAX_COUNT 10
int codegen_can_unroll_full(codeblock_t *block, ir_data_t *ir, uint32_t next_pc, uint32_t dest_addr)
{
int start;
int max_unroll;
/*Check that dest instruction was actually compiled into block*/
for (start = 0; start < ir->wr_pos; start++)
{
// pclog(" uOP %i %08x %08x\n", c, ir->uops[c].pc, dest_addr);
if (ir->uops[start].pc == dest_addr)
break;
if (ir->uops[start].pc > dest_addr)
{
// pclog("Went past dest_addr. start_pc=%08x end_pc=%08x dest_pc=%08x wr_pos=%i loop_size=%i\n", block->pc-cs, next_pc, dest_addr, ir->wr_pos, ir->wr_pos-start);
return 0;
}
}
/*Couldn't find any uOPs corresponding to the destination instruction*/
if (start == ir->wr_pos)
{
/*Is instruction jumping to itself?*/
if (dest_addr != cpu_state.oldpc)
{
// pclog("Couldn't find start. start_pc=%08x end_pc=%08x dest_pc=%08x wr_pos=%i loop_size=%i\n", block->pc-cs, next_pc, dest_addr, ir->wr_pos, ir->wr_pos-start);
return 0;
}
}
max_unroll = UNROLL_MAX_UOPS / ((ir->wr_pos-start)+6);
if (max_unroll > (UNROLL_MAX_REG_REFERENCES / max_version_refcount))
max_unroll = (UNROLL_MAX_REG_REFERENCES / max_version_refcount);
if (max_unroll > UNROLL_MAX_COUNT)
max_unroll = UNROLL_MAX_COUNT;
if (max_unroll <= 1)
return 0;
codegen_ir_set_unroll(max_unroll, start);
return 1;
}