yuzu/externals/xbyak/sample/toyvm.cpp
2020-12-28 15:15:37 +00:00

381 lines
7.0 KiB
C++
Executable File

/*
toy vm
register A, B : 32bit
PC : program counter
mem_ 4byte x 65536
すべての命令は4byte固定
即値は全て16bit
R = A or B
vldiR, imm ; R = imm
vldR, idx ; R = mem_[idx]
vstR, idx ; mem_[idx] = R
vaddiR, imm ; R += imm
vsubiR, imm ; R -= imm
vaddR, idx ; R += mem_[idx]
vsubR, idx ; R -= mem_[idx]
vputR ; print R
vjnzR, offset; if (R != 0) then jmp(PC += offset(signed))
*/
#if defined(_MSC_VER) && (_MSC_VER <= 1200)
#pragma warning(disable:4514)
#pragma warning(disable:4786)
#endif
#include <stdio.h>
#include <stdlib.h>
#include <memory.h>
#include <vector>
#define XBYAK_NO_OP_NAMES
#include "xbyak/xbyak.h"
#include "xbyak/xbyak_util.h"
#define NUM_OF_ARRAY(x) (sizeof(x) / sizeof(x[0]))
#ifdef XBYAK64
#error "only 32bit"
#endif
using namespace Xbyak;
class ToyVm : public Xbyak::CodeGenerator {
typedef std::vector<uint32> Buffer;
public:
enum Reg {
A, B
};
enum Code {
LD, LDI, ST, ADD, ADDI, SUB, SUBI, PUT, JNZ,
END_OF_CODE
};
ToyVm()
: mark_(0)
{
::memset(mem_, 0, sizeof(mem_));
}
void vldi(Reg r, uint16 imm) { encode(LDI, r, imm); }
void vld(Reg r, uint16 idx) { encode(LD, r, idx); }
void vst(Reg r, uint16 idx) { encode(ST, r, idx); }
void vadd(Reg r, uint16 idx) { encode(ADD, r, idx); }
void vaddi(Reg r, uint16 imm) { encode(ADDI, r, imm); }
void vsub(Reg r, uint16 idx) { encode(SUB, r, idx); }
void vsubi(Reg r, uint16 imm) { encode(SUBI, r, imm); }
void vjnz(Reg r, int offset) { encode(JNZ, r, static_cast<uint16>(offset)); }
void vput(Reg r) { encode(PUT, r); }
void setMark()
{
mark_ = (int)code_.size();
}
int getMarkOffset()
{
return mark_ - (int)code_.size() - 1;
}
void run()
{
bool debug = false;//true;
uint32 reg[2] = { 0, 0 };
const size_t end = code_.size();
uint32 pc = 0;
for (;;) {
uint32 x = code_[pc];
uint32 code, r, imm;
decode(code, r, imm, x);
if (debug) {
printf("---\n");
printf("A %08x B %08x\n", reg[0], reg[1]);
printf("mem_[] = %08x %08x %08x\n", mem_[0], mem_[1], mem_[2]);
printf("pc=%4d, code=%02x, r=%d, imm=%04x\n", pc, code, r, imm);
}
switch (code) {
case LDI:
reg[r] = imm;
break;
case LD:
reg[r] = mem_[imm];
break;
case ST:
mem_[imm] = reg[r];
break;
case ADD:
reg[r] += mem_[imm];
break;
case ADDI:
reg[r] += imm;
break;
case SUB:
reg[r] -= mem_[imm];
break;
case SUBI:
reg[r] -= imm;
break;
case PUT:
printf("%c %8d(0x%08x)\n", 'A' + r, reg[r], reg[r]);
break;
case JNZ:
if (reg[r] != 0) pc += static_cast<signed short>(imm);
break;
default:
assert(0);
break;
}
pc++;
if (pc >= end) break;
} // for (;;)
}
void recompile()
{
using namespace Xbyak;
/*
esi : A
edi : B
ebx : mem_
for speed up
mem_[0] : eax
mem_[1] : ecx
mem_[2] : edx
*/
push(ebx);
push(esi);
push(edi);
const Reg32 reg[2] = { esi, edi };
const Reg32 mem(ebx);
const Reg32 memTbl[] = { eax, ecx, edx };
const size_t memTblNum = NUM_OF_ARRAY(memTbl);
for (size_t i = 0; i < memTblNum; i++) xor_(memTbl[i], memTbl[i]);
xor_(esi, esi);
xor_(edi, edi);
mov(mem, (size_t)mem_);
const size_t end = code_.size();
uint32 pc = 0;
uint32 labelNum = 0;
for (;;) {
uint32 x = code_[pc];
uint32 code, r, imm;
decode(code, r, imm, x);
L(Label::toStr(labelNum++));
switch (code) {
case LDI:
mov(reg[r], imm);
break;
case LD:
if (imm < memTblNum) {
mov(reg[r], memTbl[imm]);
} else {
mov(reg[r], ptr[mem + imm * 4]);
}
break;
case ST:
if (imm < memTblNum) {
mov(memTbl[imm], reg[r]);
} else {
mov(ptr [mem + imm * 4], reg[r]);
}
break;
case ADD:
if (imm < memTblNum) {
add(reg[r], memTbl[imm]);
} else {
add(reg[r], ptr [mem + imm * 4]);
}
break;
case ADDI:
add(reg[r], imm);
break;
case SUB:
if (imm < memTblNum) {
sub(reg[r], memTbl[imm]);
} else {
sub(reg[r], ptr [mem + imm * 4]);
}
break;
case SUBI:
sub(reg[r], imm);
break;
case PUT:
{
static const char *str = "%c %8d(0x%08x)\n";
push(eax);
push(edx);
push(ecx);
push(reg[r]);
push(reg[r]);
push('A' + r);
push((int)str);
call(reinterpret_cast<const void*>(printf));
add(esp, 4 * 4);
pop(ecx);
pop(edx);
pop(eax);
}
break;
case JNZ:
test(reg[r], reg[r]);
jnz(Label::toStr(labelNum + static_cast<signed short>(imm)));
break;
default:
assert(0);
break;
}
pc++;
if (pc >= end) break;
} // for (;;)
pop(edi);
pop(esi);
pop(ebx);
ret();
}
private:
uint32 mem_[65536];
Buffer code_;
int mark_;
void decode(uint32& code, uint32& r, uint32& imm, uint32 x)
{
code = x >> 24;
r = (x >> 16) & 0xff;
imm = x & 0xffff;
}
void encode(Code code, Reg r, uint16 imm = 0)
{
uint32 x = (code << 24) | (r << 16) | imm;
code_.push_back(x);
}
};
class Fib : public ToyVm {
public:
Fib(int n)
{
if (n >= 65536) {
fprintf(stderr, "current version support only imm16\n");
return;
}
/*
A : c
B : temporary
mem_[0] : p
mem_[1] : t
mem_[2] : n
*/
vldi(A, 1); // c
vst(A, 0); // p(1)
vldi(B, static_cast<uint16>(n));
vst(B, 2); // n
// lp
setMark();
vst(A, 1); // t = c
vadd(A, 0); // c += p
vld(B, 1);
vst(B, 0); // p = t
// vput(A);
vld(B, 2);
vsubi(B, 1);
vst(B, 2); // n--
vjnz(B, getMarkOffset());
vput(A);
}
void runByJIT()
{
getCode<void (*)()>();
}
};
void fibC(uint32 n)
{
uint32 p, c, t;
p = 1;
c = 1;
lp:
t = c;
c += p;
p = t;
n--;
if (n != 0) goto lp;
printf("c=%d(0x%08x)\n", c, c);
}
int main()
{
try {
const int n = 10000;
Fib fib(n);
fib.recompile();
{
Xbyak::util::Clock clk;
clk.begin();
fib.run();
clk.end();
printf("vm %.2fKclk\n", clk.getClock() * 1e-3);
}
{
Xbyak::util::Clock clk;
clk.begin();
fib.runByJIT();
clk.end();
printf("jit %.2fKclk\n", clk.getClock() * 1e-3);
}
{
Xbyak::util::Clock clk;
clk.begin();
fibC(n);
clk.end();
printf("native C %.2fKclk\n", clk.getClock() * 1e-3);
}
} catch (std::exception& e) {
printf("ERR:%s\n", e.what());
} catch (...) {
printf("unknown error\n");
}
return 0;
}
/*
the code generated by Xbyak
push ebx
push esi
push edi
xor eax,eax
xor ecx,ecx
xor edx,edx
xor esi,esi
xor edi,edi
mov ebx,0EFF58h
mov esi,1
mov eax,esi
mov edi,2710h
mov edx,edi
.lp:
mov ecx,esi
add esi,eax
mov edi,ecx
mov eax,edi
mov edi,edx
sub edi,1
mov edx,edi
test edi,edi
jne .lp
push eax
push edx
push ecx
push esi
push esi
push 41h
push 42C434h
call printf (409342h)
add esp,10h
pop ecx
pop edx
pop eax
pop edi
pop esi
pop ebx
ret
*/