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#include "gen_x86.h"
#include "68kinst.h"
#include <stddef.h>
#include <stdio.h>
#define REX_RM_FIELD 0x1
#define REX_SIB_FIELD 0x2
#define REX_REG_FIELD 0x4
#define REX_QUAD 0x8
#define OP_ADD 0x00
#define OP_OR 0x08
#define PRE_2BYTE 0x0F
#define OP_ADC 0x10
#define OP_SBB 0x18
#define OP_AND 0x20
#define OP_SUB 0x28
#define OP_XOR 0x30
#define OP_CMP 0x38
#define PRE_REX 0x40
#define OP_PUSH 0x50
#define OP_POP 0x58
#define PRE_SIZE 0x66
#define OP_JCC 0x70
#define OP_IMMED_ARITH 0x80
#define OP_MOV 0x88
#define OP_PUSHF 0x9C
#define OP_POPF 0x9D
#define OP_MOV_I8R 0xB0
#define OP_MOV_IR 0xB8
#define OP_RETN 0xC3
#define OP_MOV_IEA 0xC6
#define OP_CALL 0xE8
#define OP_CALL_EA 0xFF
#define OP2_JCC 0x80
#define OP2_SETCC 0x90
#define OP_EX_ADDI 0x0
#define OP_EX_ORI 0x1
#define OP_EX_ADCI 0x2
#define OP_EX_SBBI 0x3
#define OP_EX_ANDI 0x4
#define OP_EX_SUBI 0x5
#define OP_EX_XORI 0x6
#define OP_EX_CMPI 0x7
#define BIT_IMMED_RAX 0x4
#define BIT_DIR 0x2
#define BIT_SIZE 0x1
#define M68K_N_REG RBX
#define M68K_V_REG BH
#define M68K_Z_REG RDX
#define M68K_C_REG DH
#define M68K_SCRATCH RCX
enum {
X86_RAX = 0,
X86_RCX,
X86_RDX,
X86_RBX,
X86_RSP,
X86_RBP,
X86_RSI,
X86_RDI,
X86_AH=4,
X86_CH,
X86_DH,
X86_BH,
X86_R8=0,
X86_R9,
X86_R10,
X86_R11,
X86_R12,
X86_R13,
X86_R14,
X86_R15
} x86_regs_enc;
enum {
MODE_REG_INDIRECT = 0,
MODE_REG_DISPLACE8 = 0x40,
MODE_REG_DIPSLACE32 = 0x80,
MODE_REG_DIRECT = 0xC0
} x86_modes;
uint8_t * x86_rr_sizedir(uint8_t * out, uint8_t opcode, uint8_t src, uint8_t dst, uint8_t size)
{
//TODO: Deal with the fact that AH, BH, CH and DH can only be in the R/M param when there's a REX prefix
uint8_t tmp;
if (size == SZ_W) {
*(out++) = PRE_SIZE;
}
if (size == SZ_B && dst >= RSP && dst <= RDI) {
opcode |= BIT_DIR;
tmp = dst;
dst = src;
src = dst;
}
if (size == SZ_Q || src >= R8 || dst >= R8 || (size == SZ_B && src >= RSP && src <= RDI)) {
*out = PRE_REX;
if (size == SZ_Q) {
*out |= REX_QUAD;
}
if (src >= R8) {
*out |= REX_REG_FIELD;
src -= (R8 - X86_R8);
}
if (dst >= R8) {
*out |= REX_RM_FIELD;
dst -= (R8 - X86_R8);
}
out++;
}
if (size == SZ_B) {
if (src >= AH && src <= BH) {
src -= (AH-X86_AH);
}
if (dst >= AH && dst <= BH) {
dst -= (AH-X86_AH);
}
} else {
opcode |= BIT_SIZE;
}
*(out++) = opcode;
*(out++) = MODE_REG_DIRECT | dst | (src << 3);
return out;
}
uint8_t * x86_rrdisp8_sizedir(uint8_t * out, uint8_t opcode, uint8_t reg, uint8_t base, int8_t disp, uint8_t size, uint8_t dir)
{
//TODO: Deal with the fact that AH, BH, CH and DH can only be in the R/M param when there's a REX prefix
uint8_t tmp;
if (size == SZ_W) {
*(out++) = PRE_SIZE;
}
if (size == SZ_Q || reg >= R8 || base >= R8 || (size == SZ_B && reg >= RSP && reg <= RDI)) {
*out = PRE_REX;
if (size == SZ_Q) {
*out |= REX_QUAD;
}
if (reg >= R8) {
*out |= REX_REG_FIELD;
reg -= (R8 - X86_R8);
}
if (base >= R8) {
*out |= REX_RM_FIELD;
base -= (R8 - X86_R8);
}
out++;
}
if (size == SZ_B) {
if (reg >= AH && reg <= BH) {
reg -= (AH-X86_AH);
}
} else {
opcode |= BIT_SIZE;
}
*(out++) = opcode | dir;
*(out++) = MODE_REG_DISPLACE8 | base | (reg << 3);
*(out++) = disp;
return out;
}
uint8_t * x86_rrind_sizedir(uint8_t * out, uint8_t opcode, uint8_t reg, uint8_t base, uint8_t size, uint8_t dir)
{
//TODO: Deal with the fact that AH, BH, CH and DH can only be in the R/M param when there's a REX prefix
uint8_t tmp;
if (size == SZ_W) {
*(out++) = PRE_SIZE;
}
if (size == SZ_Q || reg >= R8 || base >= R8 || (size == SZ_B && reg >= RSP && reg <= RDI)) {
*out = PRE_REX;
if (size == SZ_Q) {
*out |= REX_QUAD;
}
if (reg >= R8) {
*out |= REX_REG_FIELD;
reg -= (R8 - X86_R8);
}
if (base >= R8) {
*out |= REX_RM_FIELD;
base -= (R8 - X86_R8);
}
out++;
}
if (size == SZ_B) {
if (reg >= AH && reg <= BH) {
reg -= (AH-X86_AH);
}
} else {
opcode |= BIT_SIZE;
}
*(out++) = opcode | dir;
*(out++) = MODE_REG_INDIRECT | base | (reg << 3);
return out;
}
uint8_t * x86_ir(uint8_t * out, uint8_t opcode, uint8_t op_ex, uint8_t al_opcode, int32_t val, uint8_t dst, uint8_t size)
{
uint8_t sign_extend = 0;
if ((size == SZ_D || size == SZ_Q) && val <= 0x7F && val >= -0x80) {
sign_extend = 1;
opcode |= BIT_DIR;
}
if (size == SZ_W) {
*(out++) = PRE_SIZE;
}
if (dst == RAX && !sign_extend) {
if (size != SZ_B) {
al_opcode |= BIT_SIZE;
if (size == SZ_Q) {
*out = PRE_REX | REX_QUAD;
}
}
*(out++) = al_opcode | BIT_IMMED_RAX;
} else {
if (size == SZ_Q || dst >= R8 || (size == SZ_B && dst >= RSP && dst <= RDI)) {
*out = PRE_REX;
if (size == SZ_Q) {
*out |= REX_QUAD;
}
if (dst >= R8) {
*out |= REX_RM_FIELD;
dst -= (R8 - X86_R8);
}
out++;
}
if (dst >= AH && dst <= BH) {
dst -= (AH-X86_AH);
}
if (size != SZ_B) {
opcode |= BIT_SIZE;
}
*(out++) = opcode;
*(out++) = MODE_REG_DIRECT | dst | (op_ex << 3);
}
*(out++) = val;
if (size != SZ_B && !sign_extend) {
val >>= 8;
*(out++) = val;
if (size != SZ_W) {
val >>= 8;
*(out++) = val;
val >>= 8;
*(out++) = val;
}
}
return out;
}
uint8_t * add_rr(uint8_t * out, uint8_t src, uint8_t dst, uint8_t size)
{
return x86_rr_sizedir(out, OP_ADD, src, dst, size);
}
uint8_t * add_ir(uint8_t * out, int32_t val, uint8_t dst, uint8_t size)
{
return x86_ir(out, OP_IMMED_ARITH, OP_EX_ADDI, OP_ADD, val, dst, size);
}
uint8_t * or_rr(uint8_t * out, uint8_t src, uint8_t dst, uint8_t size)
{
return x86_rr_sizedir(out, OP_OR, src, dst, size);
}
uint8_t * or_ir(uint8_t * out, int32_t val, uint8_t dst, uint8_t size)
{
return x86_ir(out, OP_IMMED_ARITH, OP_EX_ORI, OP_OR, val, dst, size);
}
uint8_t * and_rr(uint8_t * out, uint8_t src, uint8_t dst, uint8_t size)
{
return x86_rr_sizedir(out, OP_AND, src, dst, size);
}
uint8_t * and_ir(uint8_t * out, int32_t val, uint8_t dst, uint8_t size)
{
return x86_ir(out, OP_IMMED_ARITH, OP_EX_ANDI, OP_AND, val, dst, size);
}
uint8_t * xor_rr(uint8_t * out, uint8_t src, uint8_t dst, uint8_t size)
{
return x86_rr_sizedir(out, OP_XOR, src, dst, size);
}
uint8_t * xor_ir(uint8_t * out, int32_t val, uint8_t dst, uint8_t size)
{
return x86_ir(out, OP_IMMED_ARITH, OP_EX_XORI, OP_XOR, val, dst, size);
}
uint8_t * sub_rr(uint8_t * out, uint8_t src, uint8_t dst, uint8_t size)
{
return x86_rr_sizedir(out, OP_SUB, src, dst, size);
}
uint8_t * sub_ir(uint8_t * out, int32_t val, uint8_t dst, uint8_t size)
{
return x86_ir(out, OP_IMMED_ARITH, OP_EX_SUBI, OP_SUB, val, dst, size);
}
uint8_t * cmp_rr(uint8_t * out, uint8_t src, uint8_t dst, uint8_t size)
{
return x86_rr_sizedir(out, OP_CMP, src, dst, size);
}
uint8_t * cmp_ir(uint8_t * out, int32_t val, uint8_t dst, uint8_t size)
{
return x86_ir(out, OP_IMMED_ARITH, OP_EX_CMPI, OP_CMP, val, dst, size);
}
uint8_t * mov_rr(uint8_t * out, uint8_t src, uint8_t dst, uint8_t size)
{
return x86_rr_sizedir(out, OP_MOV, src, dst, size);
}
uint8_t * mov_rrdisp8(uint8_t * out, uint8_t src, uint8_t dst_base, int8_t disp, uint8_t size)
{
return x86_rrdisp8_sizedir(out, OP_MOV, src, dst_base, disp, size, 0);
}
uint8_t * mov_rdisp8r(uint8_t * out, uint8_t src_base, int8_t disp, uint8_t dst, uint8_t size)
{
return x86_rrdisp8_sizedir(out, OP_MOV, dst, src_base, disp, size, BIT_DIR);
}
uint8_t * mov_rrind(uint8_t * out, uint8_t src, uint8_t dst, uint8_t size)
{
return x86_rrind_sizedir(out, OP_MOV, src, dst, size, 0);
}
uint8_t * mov_rindr(uint8_t * out, uint8_t src, uint8_t dst, uint8_t size)
{
return x86_rrind_sizedir(out, OP_MOV, dst, src, size, BIT_DIR);
}
uint8_t * mov_ir(uint8_t * out, int64_t val, uint8_t dst, uint8_t size)
{
uint8_t sign_extend = 0;
if (size == SZ_Q && val <= 0x7FFFFFFF && val >= -2147483648) {
sign_extend = 1;
}
if (size == SZ_W) {
*(out++) = PRE_SIZE;
}
if (size == SZ_Q || dst >= R8 || (size == SZ_B && dst >= RSP && dst <= RDI)) {
*out = PRE_REX;
if (size == SZ_Q) {
*out |= REX_QUAD;
}
if (dst >= R8) {
*out |= REX_RM_FIELD;
dst -= (R8 - X86_R8);
}
out++;
}
if (dst >= AH && dst <= BH) {
dst -= (AH-X86_AH);
}
if (size == SZ_B) {
*(out++) = OP_MOV_I8R;
} else if (size == SZ_Q && sign_extend) {
*(out++) = OP_MOV_IEA | BIT_SIZE;
*(out++) = MODE_REG_DIRECT | dst;
} else {
*(out++) = OP_MOV_IR;
}
*(out++) = val;
if (size != SZ_B) {
val >>= 8;
*(out++) = val;
if (size != SZ_W) {
val >>= 8;
*(out++) = val;
val >>= 8;
*(out++) = val;
if (size == SZ_Q && !sign_extend) {
val >>= 8;
*(out++) = val;
val >>= 8;
*(out++) = val;
val >>= 8;
*(out++) = val;
val >>= 8;
*(out++) = val;
}
}
}
return out;
}
uint8_t * pushf(uint8_t * out)
{
*(out++) = OP_PUSHF;
return out;
}
uint8_t * popf(uint8_t * out)
{
*(out++) = OP_POPF;
return out;
}
uint8_t * push_r(uint8_t * out, uint8_t reg)
{
if (reg >= R8) {
*(out++) = PRE_REX | REX_RM_FIELD;
reg -= R8 - X86_R8;
}
*(out++) = OP_PUSH | reg;
return out;
}
uint8_t * pop_r(uint8_t * out, uint8_t reg)
{
if (reg >= R8) {
*(out++) = PRE_REX | REX_RM_FIELD;
reg -= R8 - X86_R8;
}
*(out++) = OP_POP | reg;
return out;
}
uint8_t * setcc_r(uint8_t * out, uint8_t cc, uint8_t dst)
{
if (dst >= R8) {
*(out++) = PRE_REX | REX_RM_FIELD;
dst -= R8 - X86_R8;
} else if (dst >= RSP && dst <= RDI) {
*(out++) = PRE_REX;
} else if (dst >= AH && dst <= BH) {
dst -= AH - X86_AH;
}
*(out++) = PRE_2BYTE;
*(out++) = OP2_SETCC | cc;
*(out++) = MODE_REG_DIRECT | dst;
return out;
}
uint8_t * setcc_rind(uint8_t * out, uint8_t cc, uint8_t dst)
{
if (dst >= R8) {
*(out++) = PRE_REX | REX_RM_FIELD;
dst -= R8 - X86_R8;
}
*(out++) = PRE_2BYTE;
*(out++) = OP2_SETCC | cc;
*(out++) = MODE_REG_INDIRECT | dst;
return out;
}
uint8_t * jcc(uint8_t * out, uint8_t cc, int32_t disp)
{
if (disp <= 0x7F && disp >= -0x80) {
*(out++) = OP_JCC | cc;
*(out++) = disp;
} else {
*(out++) = PRE_2BYTE;
*(out++) = OP2_JCC | cc;
*(out++) = disp;
disp >>= 8;
*(out++) = disp;
disp >>= 8;
*(out++) = disp;
disp >>= 8;
*(out++) = disp;
}
return out;
}
uint8_t * call(uint8_t * out, uint8_t * fun)
{
ptrdiff_t disp = fun-(out+5);
if (disp <= 0x7FFFFFFF && disp >= -2147483648) {
*(out++) = OP_CALL;
*(out++) = disp;
disp >>= 8;
*(out++) = disp;
disp >>= 8;
*(out++) = disp;
disp >>= 8;
*(out++) = disp;
} else {
//TODO: Implement far call
printf("%p - %p = %ld, %d, %d, %d\n", fun, out + 5, disp, disp <= 0x7FFFFFFF, disp >= (-2147483648), -2147483648);
return NULL;
}
return out;
}
uint8_t * retn(uint8_t * out)
{
*(out++) = OP_RETN;
return out;
}
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