diff options
author | dec05eba <dec05eba@protonmail.com> | 2019-08-12 09:48:55 +0200 |
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committer | dec05eba <dec05eba@protonmail.com> | 2020-07-25 14:36:46 +0200 |
commit | ea97370f973374f863e4296c2bb872be8b5235a3 (patch) | |
tree | bcf74846c250dd5b1f84049622ed2766605365e7 /src/asm | |
parent | 4ca3b74621c3608de42a91730a71892d9d7c27b5 (diff) |
Before interpreter. Cleanup build script. Begin writing code analyzer tool to find common mistakes
Diffstat (limited to 'src/asm')
-rw-r--r-- | src/asm/x86_64.c | 385 |
1 files changed, 0 insertions, 385 deletions
diff --git a/src/asm/x86_64.c b/src/asm/x86_64.c deleted file mode 100644 index e246fbc..0000000 --- a/src/asm/x86_64.c +++ /dev/null @@ -1,385 +0,0 @@ -#include "../../include/asm/x86_64.h" - -#include "../../include/std/mem.h" -#include "../../include/std/log.h" -#include <errno.h> -#include <assert.h> -#include <stdio.h> - -#include <sys/mman.h> - -#define REX_W 0x48 - -void asm_ptr_init(AsmPtr *self, Reg64 base) { - self->base = base; - self->index = -1; - self->disp = 0; - self->scale = 0; -} - -void asm_ptr_init_index(AsmPtr *self, Reg64 base, Reg64 index) { - self->base = base; - self->index = index; - self->disp = 0; - self->scale = 0; -} - -void asm_ptr_init_disp(AsmPtr *self, Reg64 base, i32 disp) { - self->base = base; - self->index = -1; - self->disp = disp; - self->scale = 0; -} - -void asm_ptr_init_index_disp(AsmPtr *self, Reg64 base, Reg64 index, i32 disp) { - self->base = base; - self->index = index; - self->disp = disp; - self->scale = 0; -} - -int asm_init(Asm *self) { - self->size = am_pagesize(); - amal_log_debug("asm: page size: %u", self->size); - self->code = mmap(NULL, self->size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - if(self->code == MAP_FAILED) - return -errno; - self->code_it = self->code; - return 0; -} - -void asm_deinit(Asm *self) { - if(self->code) - munmap(self->code, self->size); - self->code = NULL; - self->code_it = NULL; - self->size = 0; -} - -static void asm_print_code_hex(Asm *self) { - u8 *ptr; - int off; - ptr = self->code; - off = 0; - while(ptr != self->code_it) { - printf("%02x", *ptr); - ++ptr; - ++off; - if(off == 8) { - putc('\n', stdout); - off = 0; - } else { - putc(' ', stdout); - } - } - if(off != 0) - putc('\n', stdout); -} - -int asm_execute(Asm *self) { - void (*func)(); - if(mprotect(self->code, self->size, PROT_READ | PROT_EXEC) != 0) - return -errno; - - asm_print_code_hex(self); - - /* TODO: Verify if this is valid on all platforms. According to ISO C standard it isn't? */ - *(void**)(&func) = self->code; - func(); - return 0; -} - -/* TODO: See how this can be optimized */ -static CHECK_RESULT int asm_ensure_capacity(Asm *self, usize size) { - usize current_offset; - current_offset = (u8*)self->code_it - (u8*)self->code; - if(current_offset + size > self->size) { - void *new_mem; - usize new_size; - new_size = self->size + am_pagesize(); - new_mem = mmap(NULL, new_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); - if(self->code == MAP_FAILED) - return -errno; - - am_memcpy(new_mem, self->code, self->size); - self->code = new_mem; - self->size = new_size; - self->code_it = (u8*)self->code + current_offset; - } - return 0; -} - -#ifdef DEBUG -static isize asm_get_capacity_left(Asm *self) { - return (isize)self->size - (isize)((u8*)self->code_it - (u8*)self->code); -} -#endif - -int asm_nop(Asm *self) { - return_if_error(asm_ensure_capacity(self, 1)); - *self->code_it++ = 0x90; - return 0; -} - -static i32 abs_i32(i32 value) { - return value >= 0 ? value : -value; -} - -/* -TODO: Implement 1 and 2 byte displacement? -There has to be at least 6 bytes left in the asm buffer before calling this function. -*/ -static void asm_rm(Asm *self, AsmPtr *mem, Reg64 reg) { - u8 rm_byte; - u8 disp_bytes; - assert(asm_get_capacity_left(self) >= 6); - if((int)mem->index != -1) { - u8 sib_offset; - if(mem->disp == 0) { - rm_byte = 0x04; - disp_bytes = 0; - } else if(abs_i32(mem->disp) <= INT8_MAX) { - rm_byte = 0x44; - disp_bytes = 1; - } else { - rm_byte = 0x84; - disp_bytes = 4; - } - - #ifdef DEBUG - if(mem->scale != 0 && mem->scale != 2 && mem->scale != 4 && mem->scale != 8) { - amal_log_error("Invalid scale %d, expected 0, 2, 4, or 8", mem->scale); - assert(bool_false); - } - #endif - assert(mem->base != RBP && "TODO: Implement RBP base for sib byte. RBP is special and requires different logic"); - sib_offset = (mem->scale << 5) + 8*mem->index + mem->base; - - *self->code_it++ = rm_byte; - *self->code_it++ = sib_offset; - } else { - if(mem->disp == 0) { - if(mem->base == RBP) { - rm_byte = 0x45; - disp_bytes = 1; - } else { - rm_byte = mem->base; - disp_bytes = 0; - } - } else if(abs_i32(mem->disp) <= INT8_MAX) { - rm_byte = 0x40 + mem->base; - disp_bytes = 1; - } else { - rm_byte = 0x80 + mem->base; - disp_bytes = 4; - } - *self->code_it++ = (reg << 3) | rm_byte; - } - - am_memcpy(self->code_it, &mem->disp, disp_bytes); - self->code_it += disp_bytes; -} - -/* There has to be at least 1 byte left in the asm buffer before calling this function. */ -static void asm_rr(Asm *self, Reg64 dst, Reg64 src) { - assert(asm_get_capacity_left(self) >= 1); - *self->code_it++ = 0xC0 + dst + 8*src; -} - -/* TODO: Implement 1 and 2 byte immediate? */ -int asm_mov_mi(Asm *self, AsmPtr *dst, i32 immediate) { - /* 12 bytes is the maximum size of the instruction. We don't how how large it will be so we prepare for the largest size */ - return_if_error(asm_ensure_capacity(self, 12)); - *self->code_it++ = REX_W; - *self->code_it++ = 0xC7; - asm_rm(self, dst, 0); - am_memcpy(self->code_it, &immediate, sizeof(immediate)); - self->code_it += sizeof(immediate); - return 0; -} - -int asm_mov_mr(Asm *self, AsmPtr *dst, Reg64 src) { - /* 8 bytes is the maximum size of the instruction. We don't how how large it will be so we prepare for the largest size */ - return_if_error(asm_ensure_capacity(self, 8)); - *self->code_it++ = REX_W; - *self->code_it++ = 0x89; - asm_rm(self, dst, src); - return 0; -} - -int asm_mov_rm(Asm *self, Reg64 dst, AsmPtr *src) { - /* 8 bytes is the maximum size of the instruction. We don't how how large it will be so we prepare for the largest size */ - return_if_error(asm_ensure_capacity(self, 8)); - *self->code_it++ = REX_W; - *self->code_it++ = 0x8B; - asm_rm(self, src, dst); - return 0; -} - -int asm_mov_ri(Asm *self, Reg64 dst, i64 immediate) { - /* 10 bytes is the maximum size of the instruction. We don't how how large it will be so we prepare for the largest size */ - return_if_error(asm_ensure_capacity(self, 10)); - *self->code_it++ = REX_W; - *self->code_it++ = 0xB8 + dst; - am_memcpy(self->code_it, &immediate, sizeof(immediate)); - self->code_it += sizeof(immediate); - return 0; -} - -int asm_mov_rr(Asm *self, Reg64 dst, Reg64 src) { - /* 3 bytes is the maximum size of the instruction. We don't how how large it will be so we prepare for the largest size */ - return_if_error(asm_ensure_capacity(self, 3)); - *self->code_it++ = REX_W; - *self->code_it++ = 0x89; - asm_rr(self, dst, src); - return 0; -} - -int asm_add_rr(Asm *self, Reg64 dst, Reg64 src) { - /* 3 bytes is the maximum size of the instruction. We don't how how large it will be so we prepare for the largest size */ - return_if_error(asm_ensure_capacity(self, 3)); - *self->code_it++ = REX_W; - *self->code_it++ = 0x01; - asm_rr(self, dst, src); - return 0; -} - -int asm_sub_rr(Asm *self, Reg64 dst, Reg64 src) { - /* 3 bytes is the maximum size of the instruction. We don't how how large it will be so we prepare for the largest size */ - return_if_error(asm_ensure_capacity(self, 3)); - *self->code_it++ = REX_W; - *self->code_it++ = 0x29; - asm_rr(self, dst, src); - return 0; -} - -int asm_imul_rr(Asm *self, Reg64 dst, Reg64 src) { - /* 3 bytes is the maximum size of the instruction. We don't how how large it will be so we prepare for the largest size */ - return_if_error(asm_ensure_capacity(self, 4)); - *self->code_it++ = REX_W; - *self->code_it++ = 0x0F; - *self->code_it++ = 0xAF; - asm_rr(self, dst, src); - return 0; -} - -int asm_pushr(Asm *self, Reg64 reg) { - return_if_error(asm_ensure_capacity(self, 1)); - *self->code_it++ = 0x50 + reg; - return 0; -} - -int asm_popr(Asm *self, Reg64 reg) { - return_if_error(asm_ensure_capacity(self, 1)); - *self->code_it++ = 0x58 + reg; - return 0; -} - -/* /r */ -#define DEFINE_INS_RM(mnemonic, opcode) \ -int asm_##mnemonic##_rm32(Asm *self, Reg32 dst, Reg32 src) { \ - return_if_error(asm_ensure_capacity(self, 2)); \ - *self->code_it++ = opcode; \ - *self->code_it++ = 0xC0 + 8*dst + src; \ - return 0; \ -} \ - \ -int asm_##mnemonic##_rm64(Asm *self, Reg64 dst, Reg64 src) { \ - return_if_error(asm_ensure_capacity(self, 1)); \ - *self->code_it++ = REX_W; \ - return asm_##mnemonic##_rm32(self, (Reg32)dst, (Reg32)src); \ -} - -DEFINE_INS_RM(mov, 0x8B) -DEFINE_INS_RM(add, 0x03) -DEFINE_INS_RM(sub, 0x2B) -DEFINE_INS_RM(and, 0x23) -DEFINE_INS_RM(or, 0x0B) -DEFINE_INS_RM(xor, 0x33) -DEFINE_INS_RM(cmp, 0x3B) - -/* - /number - The number is called the extension, a number from 0 to 7; - It's a number used to extend the opcode type, since the instruction only uses - one register the other register can be encoded for that. -*/ -#define DEFINE_INS_EXT_IMM(mnemonic, extension) \ -int asm_##mnemonic##_rm32_imm(Asm *self, Reg32 reg, i32 immediate) { \ - if(abs_i32(immediate) <= INT8_MAX) { \ - return_if_error(asm_ensure_capacity(self, 3)); \ - *self->code_it++ = 0x83; \ - *self->code_it++ = 0xC0 + 8*extension + reg; \ - *self->code_it++ = (u8)immediate; \ - } else { \ - return_if_error(asm_ensure_capacity(self, 6)); \ - *self->code_it++ = 0x81; \ - *self->code_it++ = 0xC0 + 8*extension + reg; \ - am_memcpy(self->code_it, &immediate, sizeof(immediate)); \ - self->code_it += sizeof(immediate); \ - } \ - return 0; \ -} \ - \ -int asm_##mnemonic##_rm64_imm(Asm *self, Reg64 reg, i32 immediate) { \ - return_if_error(asm_ensure_capacity(self, 1)); \ - *self->code_it++ = REX_W; \ - return asm_##mnemonic##_rm32_imm(self, (Reg32)reg, immediate); \ -} - -DEFINE_INS_EXT_IMM(add, 0) -DEFINE_INS_EXT_IMM(or, 1) -DEFINE_INS_EXT_IMM(adc, 2) -DEFINE_INS_EXT_IMM(sbb, 3) -DEFINE_INS_EXT_IMM(and, 4) -DEFINE_INS_EXT_IMM(sub, 5) -DEFINE_INS_EXT_IMM(xor, 6) -DEFINE_INS_EXT_IMM(cmp, 7) - -/* - /number - The number is called the extension, a number from 0 to 7; - It's a number used to extend the opcode type, since the instruction only uses - one register the other register can be encoded for that. -*/ -#define DEFINE_INS_SHIFT_IMM8(mnemonic, extension) \ -int asm_##mnemonic##_rm32_imm(Asm *self, Reg32 reg, i8 immediate) { \ - if(immediate == 1) { \ - return_if_error(asm_ensure_capacity(self, 2)); \ - *self->code_it++ = 0xC1; \ - *self->code_it++ = 0xC0 + 8*reg + extension; \ - } else { \ - return_if_error(asm_ensure_capacity(self, 3)); \ - *self->code_it++ = 0xD1; \ - *self->code_it++ = 0xC0 + 8*reg + extension; \ - *self->code_it++ = immediate; \ - } \ - return 0; \ -} \ - \ -int asm_##mnemonic##_rm64_imm(Asm *self, Reg64 reg, i8 immediate) { \ - return_if_error(asm_ensure_capacity(self, 1)); \ - *self->code_it++ = REX_W; \ - return asm_##mnemonic##_rm32_imm(self, (Reg32)reg, immediate); \ -} - -DEFINE_INS_SHIFT_IMM8(rol, 0) -DEFINE_INS_SHIFT_IMM8(ror, 1) -DEFINE_INS_SHIFT_IMM8(rcl, 2) -DEFINE_INS_SHIFT_IMM8(rcr, 3) -DEFINE_INS_SHIFT_IMM8(shl, 4) -DEFINE_INS_SHIFT_IMM8(shr, 5) -/*DEFINE_INS_SHIFT_IMM8(shl, 6)*/ -DEFINE_INS_SHIFT_IMM8(sar, 7) - -int asm_ret(Asm *self, u16 bytes) { - if(bytes == 0) { - return_if_error(asm_ensure_capacity(self, 1)); - *self->code_it++ = 0xC3; - } else { - return_if_error(asm_ensure_capacity(self, 3)); - *self->code_it++ = 0xC2; - am_memcpy(self->code_it, &bytes, sizeof(bytes)); - } - return 0; -} |