jit-tutorial/mandeljit.c

87 lines
2.5 KiB
C

// mandeljit.c
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include "micro-asm.h"
#define sqr(x) ((x) * (x))
typedef struct { double r; double i; } complex;
typedef void(*compiled)(complex*);
#define offsetof(type, field) ((unsigned long) &(((type *) 0)->field))
compiled compile(char *code) {
char *memory = mmap(NULL, 4096, PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
microasm a = { .dest = memory };
char src_dsp, dst_dsp;
char const r = offsetof(complex, r);
char const i = offsetof(complex, i);
for (; *code; code += 3) {
src_dsp = sizeof(complex) * (code[1] - 'a');
dst_dsp = sizeof(complex) * (code[2] - 'a');
switch (*code) {
case '=':
movpd_memory_reg(&a, src_dsp, xmm(0));
movpd_reg_memory(&a, xmm(0), dst_dsp);
break;
case '+':
movpd_memory_reg(&a, src_dsp, xmm(0));
addpd_memory_reg(&a, dst_dsp, xmm(0));
movpd_reg_memory(&a, xmm(0), dst_dsp);
break;
case '*':
movsd_memory_reg(&a, src_dsp + r, xmm(0));
movsd_memory_reg(&a, src_dsp + i, xmm(1));
movsd_memory_reg(&a, dst_dsp + r, xmm(2));
movsd_memory_reg(&a, dst_dsp + i, xmm(3));
movsd_reg_reg (&a, xmm(0), xmm(4));
mulsd (&a, xmm(2), xmm(4));
movsd_reg_reg (&a, xmm(1), xmm(5));
mulsd (&a, xmm(3), xmm(5));
subsd (&a, xmm(5), xmm(4));
movsd_reg_memory(&a, xmm(4), dst_dsp + r);
mulsd (&a, xmm(0), xmm(3));
mulsd (&a, xmm(1), xmm(2));
addsd (&a, xmm(3), xmm(2));
movsd_reg_memory(&a, xmm(2), dst_dsp + i);
break;
default:
fprintf(stderr, "undefined instruction %s (ASCII %x)\n", code, *code);
exit(1);
}
}
// Return to caller (important!)
asm_write(&a, 1, 0xc3);
return (compiled) memory;
}
int main(int argc, char **argv) {
compiled fn = compile(argv[1]);
complex registers[4];
int i, x, y;
char line[1600];
printf("P5\n%d %d\n%d\n", 1600, 900, 255);
for (y = 0; y < 900; ++y) {
for (x = 0; x < 1600; ++x) {
registers[0].r = 2 * 1.6 * (x / 1600.0 - 0.5);
registers[0].i = 2 * 0.9 * (y / 900.0 - 0.5);
for (i = 1; i < 4; ++i) registers[i].r = registers[i].i = 0;
for (i = 0; i < 256 && sqr(registers[1].r) + sqr(registers[1].i) < 4; ++i)
(*fn)(registers);
line[x] = i;
}
fwrite(line, 1, sizeof(line), stdout);
}
return 0;
}