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encoreall.c
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encoreall.c
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#include "minx86dec/types.h"
#include "minx86dec/state.h"
#include "minx86dec/opcodes.h"
#include "minx86dec/coreall.h"
#include "minx86dec/opcodes_str.h"
#include "minx86dec/encoreall.h"
#include <string.h>
#include <stdio.h>
static inline minx86_write_ptr_t minx86enc_32_sse_mod(struct minx86dec_argv *a,struct minx86enc_state *est,minx86_write_ptr_t o,unsigned int wordsize) {
if (a->regtype == MX86_RT_NONE && (a->memregsz>>2)^(est->addr32?1:0)) *o++ = 0x67;
if ((wordsize?1:0)/*^(est->data32?1:0)*/) *o++ = 0x66;
return o;
}
/* code will call this to generate the appropriate 386 data override prefix.
* if 16-bit mode and the arg provided is 32 bits wide, OR
* if 32-bit mode and the arg provided is 16 bits wide */
static inline minx86_write_ptr_t minx86enc_32_overrides(struct minx86dec_argv *a,struct minx86enc_state *est,minx86_write_ptr_t o,unsigned int wordsize) {
if (a->regtype == MX86_RT_NONE && (a->memregsz>>2)^(est->addr32?1:0)) *o++ = 0x67;
if (wordsize && ((a->size>>2)^(est->data32?1:0))) *o++ = 0x66;
return o;
}
/* this alternate version for instructions like MOVSX where the destination is larger than source (a=reg, b=mem) */
static inline minx86_write_ptr_t minx86enc_32_overrides_movsx(struct minx86dec_argv *a,struct minx86dec_argv *b,struct minx86enc_state *est,minx86_write_ptr_t o,unsigned int wordsize) {
if (b->regtype == MX86_RT_NONE && (b->memregsz>>2)^(est->addr32?1:0)) *o++ = 0x67;
if (wordsize && ((a->size>>2)^(est->data32?1:0))) *o++ = 0x66;
return o;
}
static inline minx86_write_ptr_t minx86enc_32_overrides_far(struct minx86dec_argv *a,struct minx86enc_state *est,minx86_write_ptr_t o,unsigned int wordsize) {
if (a->regtype == MX86_RT_NONE && (a->memregsz>>2)^(est->addr32?1:0)) *o++ = 0x67;
if (wordsize && (((a->size==6)?1:0)^(est->data32?1:0))) *o++ = 0x66;
return o;
}
minx86_write_ptr_t minx86enc_encode_rm_reg(struct minx86dec_argv *a,unsigned int reg,unsigned int rm,minx86_write_ptr_t o) {
*o++ = (3 << 6) | (reg << 3) | rm;
return o;
}
minx86_write_ptr_t minx86enc_seg_overrides(struct minx86dec_argv *a,struct minx86enc_state *est,minx86_write_ptr_t o,int force_seg_override) {
int need_ds = 0,i;
if (a->memregs != 0) {
/* if any reference is made to EBP/ESP then assume you need DS to encode DS ref */
for (i=0;i < a->memregs;i++) {
if (a->memreg[i] == MX86_REG_SP || a->memreg[i] == MX86_REG_BP)
need_ds = 1;
}
}
if (a->segment == MX86_SEG_DS) {
if (force_seg_override || need_ds) *o++ = 0x3E; /* DS: */
}
else if (a->segment == MX86_SEG_SS) {
if (force_seg_override || !need_ds) *o++ = 0x36; /* SS: */
}
else if (a->segment == MX86_SEG_ES) {
*o++ = 0x26;
}
else if (a->segment == MX86_SEG_CS) {
*o++ = 0x2E;
}
else if (a->segment == MX86_SEG_FS) {
*o++ = 0x64;
}
else if (a->segment == MX86_SEG_GS) {
*o++ = 0x65;
}
return o;
}
minx86_write_ptr_t minx86enc_seg_overrides_es(struct minx86dec_argv *a,struct minx86enc_state *est,minx86_write_ptr_t o,int force_seg_override) {
if (a->segment == MX86_SEG_DS) {
*o++ = 0x3E; /* DS: */
}
else if (a->segment == MX86_SEG_SS) {
*o++ = 0x36; /* SS: */
}
else if (a->segment == MX86_SEG_ES) {
if (force_seg_override) *o++ = 0x26;
}
else if (a->segment == MX86_SEG_CS) {
*o++ = 0x2E;
}
else if (a->segment == MX86_SEG_FS) {
*o++ = 0x64;
}
else if (a->segment == MX86_SEG_GS) {
*o++ = 0x65;
}
return o;
}
minx86_write_ptr_t minx86enc_encode_memreg_far(struct minx86dec_argv *a,minx86_write_ptr_t o,unsigned int regval) {
int mod = 0,memref = 0;
if (a->memref_base != 0) {
if ( (a->memregsz == 4 && (int32_t)a->memref_base >= -0x80 && (int32_t)a->memref_base < 0x80) ||
(a->memregsz == 2 && (int16_t)a->memref_base >= -0x80 && (int16_t)a->memref_base < 0x80))
mod = 1;
else
mod = 2;
}
if (a->memregs == 1) {
if (a->memregsz == 4) {/* 32-bit */
if (mod == 0) {
if (a->memreg[0] == 5)
mod = 1; /* [EBP] -> [EBP+0] */
}
*o++ = (mod << 6) | (regval << 3) | a->memreg[0];
{
if (a->memreg[0] == 4) {
/* the code for [ESP] is used instead for
* encoding the SIB so we must encode the SIB byte
* to properly make [ESP] reference */
*o++ = (a->scalar << 6) | (4 << 3) | MX86_REG_ESP; /* scale=s/index=none/base=ESP */
}
}
}
else {/* 16-bit */
switch (a->memreg[0]) {
case MX86_REG_SI: *o++ = 4 | (regval << 3) | (mod<<6); break;
case MX86_REG_DI: *o++ = 5 | (regval << 3) | (mod<<6); break;
case MX86_REG_BP: {
if (mod == 0) mod = 1; /* No such [BP] must encode as [BP+0] */
*o++ = 6 | (regval << 3) | (mod<<6); } break;
case MX86_REG_BX: *o++ = 7 | (regval << 3) | (mod<<6); break;
}
}
}
else if (a->memregs == 2) {
if (a->memregsz == 4) {/* 32-bit */
if (mod == 0) {
if (a->memreg[0] == 5 || a->memreg[1] == 5)
mod = 1; /* [EBP] -> [EBP+0] */
}
*o++ = (mod << 6) | (regval << 3) | 4; /* SIB */
*o++ = (a->scalar << 6) | (a->memreg[0] << 3) | a->memreg[1]; /* scale=s/index=none/base=ESP */
}
else {/* 16-bit */
uint8_t c = 0;
/* BX or BP */
switch (a->memreg[0]) {
case MX86_REG_BP: c = 2; break;
}
/* second one may be SI or DI */
switch (a->memreg[1]) {
case MX86_REG_DI: c |= 1; break;
}
*o++ = c | (regval << 3) | (mod<<6);
}
}
else if (a->memregs == 0) {
/* direct memory reference */
mod = 0;
memref = 1;
if (a->memregsz == 4) {/* 32-bit */
*o++ = 5 | (regval << 3) | (mod<<6);
}
else {
*o++ = 6 | (regval << 3) | (mod<<6);
}
}
if (mod == 1)
*o++ = (uint8_t)(a->memref_base);
else if (mod == 2 || (mod == 0 && memref)) {
if (a->memregsz == 4) {
*((uint32_t*)o) = (uint32_t)(a->memref_base);
o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)(a->memref_base);
o += 2;
}
}
return o;
}
minx86_write_ptr_t minx86enc_encode_memreg(struct minx86dec_argv *a,minx86_write_ptr_t o,unsigned int regval) {
int mod = 0,memref = 0;
if (a->memref_base != 0) {
if ( (a->memregsz == 4 && (int32_t)a->memref_base >= -0x80 && (int32_t)a->memref_base < 0x80) ||
(a->memregsz == 2 && (int16_t)a->memref_base >= -0x80 && (int16_t)a->memref_base < 0x80))
mod = 1;
else
mod = 2;
}
if (a->memregs == 1) {
if (a->memregsz == 4) {/* 32-bit */
if (mod == 0) {
if (a->memreg[0] == 5)
mod = 1; /* [EBP] -> [EBP+0] */
}
*o++ = (mod << 6) | (regval << 3) | a->memreg[0];
{
if (a->memreg[0] == 4) {
/* the code for [ESP] is used instead for
* encoding the SIB so we must encode the SIB byte
* to properly make [ESP] reference */
*o++ = (a->scalar << 6) | (4 << 3) | MX86_REG_ESP; /* scale=s/index=none/base=ESP */
}
}
}
else {/* 16-bit */
switch (a->memreg[0]) {
case MX86_REG_SI: *o++ = 4 | (regval << 3) | (mod<<6); break;
case MX86_REG_DI: *o++ = 5 | (regval << 3) | (mod<<6); break;
case MX86_REG_BP: {
if (mod == 0) mod = 1; /* No such [BP] must encode as [BP+0] */
*o++ = 6 | (regval << 3) | (mod<<6); } break;
case MX86_REG_BX: *o++ = 7 | (regval << 3) | (mod<<6); break;
}
}
}
else if (a->memregs == 2) {
if (a->memregsz == 4) {/* 32-bit */
if (mod == 0) {
if (a->memreg[1] == 5)
mod = 1; /* [EBP] -> [EBP+0] */
}
*o++ = (mod << 6) | (regval << 3) | 4; /* SIB */
*o++ = (a->scalar << 6) | (a->memreg[0] << 3) | a->memreg[1]; /* scale=s/index=none/base=ESP */
}
else {/* 16-bit */
uint8_t c = 0;
/* BX or BP */
switch (a->memreg[0]) {
case MX86_REG_BP: c = 2; break;
}
/* second one may be SI or DI */
switch (a->memreg[1]) {
case MX86_REG_DI: c |= 1; break;
}
*o++ = c | (regval << 3) | (mod<<6);
}
}
else if (a->memregs == 0) {
/* direct memory reference */
mod = 0;
memref = 1;
if (a->memregsz == 4) {/* 32-bit */
*o++ = 5 | (regval << 3) | (mod<<6);
}
else {
*o++ = 6 | (regval << 3) | (mod<<6);
}
}
if (mod == 1)
*o++ = (uint8_t)(a->memref_base);
else if (mod == 2 || (mod == 0 && memref)) {
if (a->memregsz == 4) {
*((uint32_t*)o) = (uint32_t)(a->memref_base);
o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)(a->memref_base);
o += 2;
}
}
return o;
}
void minx86enc_encodeall(struct minx86enc_state *est,struct minx86dec_instruction *ins) {
minx86_write_ptr_t o = est->write_ip;
est->started_here = o;
switch (ins->opcode) {
case MXOP_JMP: { /*====================NEAR JMP===================*/
struct minx86dec_argv *a = &ins->argv[0];
if (a->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0xFF; *o++ = (3<<6) | (4<<3) | a->reg; /* mod=3 reg=4 rm=reg */
}
else if (a->regtype == MX86_RT_NONE) {
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0xFF; o = minx86enc_encode_memreg(a,o,4);
}
else if (a->regtype == MX86_RT_IMM) { /* hope you set est->ip_value! encoding is RELATIVE! */
int32_t delta = (int32_t)(a->value - est->ip_value),extra = (int32_t)(o - est->started_here);
/* if it's small enough, encode as single-byte JMP */
if ((delta-(2+extra)) >= -0x80 && (delta-(2+extra)) < 0x80)
{ /*o = minx86enc_32_overrides(a,est,o,1);*/ *o++ = 0xEB; *o++ = (uint8_t)(delta-(2+extra)); }
/* if the encoding is for 32-bit mode, OR the delta is too large for 16-bit mode: */
else if (est->addr32 || !((delta-(5+extra)) >= -0x8000 && (delta-(5+extra)) < 0x8000))
{ if (!est->addr32) { *o++ = 0x66; extra++; }; *o++ = 0xE9; *((uint32_t*)o) = (uint32_t)(delta-(5+extra)); o += 4; }
else
{ *o++ = 0xE9; *((uint16_t*)o) = (uint16_t)(delta-(3+extra)); o += 2; }
}
} break;
case MXOP_JMP_FAR: { /*=====================FAR JMP====================*/
struct minx86dec_argv *ofs=&ins->argv[0];
if (ofs->regtype == MX86_RT_IMM) { /* easy: seg:off values are absolute */
if (est->addr32 || (ofs->value & 0xFFFF0000)) {
if (!est->addr32) *o++ = 0x66;
*o++ = 0xEA;
*((uint32_t*)o) = (uint32_t)ofs->value; o += 4;
}
else {
*o++ = 0xEA;
*((uint16_t*)o) = (uint16_t)ofs->value; o += 2;
}
/* segment */
*((uint16_t*)o) = (uint16_t)ofs->segval; o += 2;
}
else if (ofs->regtype == MX86_RT_NONE) {
o = minx86enc_32_overrides_far(ofs,est,o,1);
*o++ = 0xFF; o = minx86enc_encode_memreg_far(ofs,o,5);
}
} break;
case MXOP_CALL: { /*====================NEAR CALL===================*/
struct minx86dec_argv *a = &ins->argv[0];
if (a->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0xFF; *o++ = (3<<6) | (2<<3) | a->reg; /* mod=3 reg=6 rm=reg */
}
else if (a->regtype == MX86_RT_NONE) {
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0xFF; o = minx86enc_encode_memreg(a,o,2);
}
else if (a->regtype == MX86_RT_IMM) { /* hope you set est->ip_value! encoding is RELATIVE! */
int32_t delta = (int32_t)(a->value - est->ip_value),extra = (int32_t)(o - est->started_here);
/* no such thing as single-byte CALL. */
/* if the encoding is for 32-bit mode, OR the delta is too large for 16-bit mode: */
if (est->addr32 || !((delta-(5+extra)) >= -0x8000 && (delta-(5+extra)) < 0x8000))
{ if (!est->addr32) { *o++ = 0x66; extra++;}; *o++ = 0xE8; *((uint32_t*)o) = (uint32_t)(delta-(5+extra)); o += 4; }
else
{ *o++ = 0xE8; *((uint16_t*)o) = (uint16_t)(delta-(3+extra)); o += 2; }
}
} break;
case MXOP_CALL_FAR: { /*=====================FAR CALL====================*/
struct minx86dec_argv *ofs=&ins->argv[0];
if (ofs->regtype == MX86_RT_IMM) { /* easy: seg:off values are absolute */
if (est->addr32 || (ofs->value & 0xFFFF0000)) {
if (!est->addr32) *o++ = 0x66;
*o++ = 0x9A;
*((uint32_t*)o) = (uint32_t)ofs->value; o += 4;
}
else {
*o++ = 0x9A;
*((uint16_t*)o) = (uint16_t)ofs->value; o += 2;
}
/* segment */
*((uint16_t*)o) = (uint16_t)ofs->segval; o += 2;
}
else if (ofs->regtype == MX86_RT_NONE) {
o = minx86enc_32_overrides_far(ofs,est,o,1);
*o++ = 0xFF; o = minx86enc_encode_memreg_far(ofs,o,3);
}
} break;
case MXOP_NOP: { /*====================NOP====================*/
struct minx86dec_argv *a=&ins->argv[0];
if (ins->lock) *o++ = 0xF0;
if (ins->argc == 0) {
*o++ = 0x90;
}
else if (a->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0x0F; *o++ = 0x1F;
*o++ = (3 << 6) | (0 << 3) | a->reg;
}
else if (a->regtype == MX86_RT_NONE && a->memregs > 0) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0x0F; *o++ = 0x1F;
o = minx86enc_encode_memreg(a,o,0);
}
else {
*o++ = 0x90;
}
} break;
case MXOP_XCHG: { /*========================XCHG======================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
unsigned char word = (a->size >= 2) ? 1 : 0;
/* make sure a is r/m and b is reg. ASSUME: both are the same datasize */
if (b->regtype == MX86_RT_NONE) { struct minx86dec_argv *t = a; a = b; b = t; }
if (ins->lock) *o++ = 0xF0;
o = minx86enc_32_overrides(a,est,o,word);
if (a->regtype == MX86_RT_REG) {
if (word && a->reg == MX86_REG_AX)
*o++ = 0x90 + b->reg;
else if (word && b->reg == MX86_REG_AX)
*o++ = 0x90 + a->reg;
else {
*o++ = 0x86 + word;
*o++ = (3 << 6) | (b->reg << 3) | a->reg;
}
}
else { /* xchg r/m, reg */
*o++ = 0x86 + word; o = minx86enc_encode_memreg_far(a,o,b->reg);
}
} break;
case MXOP_MOV: { /*====================MOV=====================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
unsigned char word = (a->size >= 2) ? 1 : 0;
/* it doesn't matter if it's reg-reg, reg-r/m, r/m-reg, etc
* instruction encoding covers them all */
if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x88+word; *o++ = (3<<6) | (b->reg<<3) | (a->reg);
}
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_IMM) {
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0xB0+(word<<3)+a->reg;
if (word) {
if (a->size == 4) {
*((uint32_t*)o) = (uint32_t)(b->value); o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)(b->value); o += 2;
}
}
else {
*o++ = (uint8_t)(b->value);
}
}
else if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_IMM) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0xC6 + word; o = minx86enc_encode_memreg(a,o,0);
if (word) {
if (a->size == 4) {
*((uint32_t*)o) = (uint32_t)(b->value); o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)(b->value); o += 2;
}
}
else {
*o++ = (uint8_t)(b->value);
}
}
else if (a->regtype == MX86_RT_NONE && a->memregs == 0 && b->regtype == MX86_RT_REG && b->reg == MX86_REG_AX) {
/* aka: MOV [memaddr],A */
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0xA2 + word;
if (a->memregsz == 4) {
*((uint32_t*)o) = (uint32_t)(a->memref_base); o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)(a->memref_base); o += 2;
}
}
else if (b->regtype == MX86_RT_NONE && b->memregs == 0 && a->regtype == MX86_RT_REG && a->reg == MX86_REG_AX) {
/* aka: MOV A,[memaddr] */
o = minx86enc_seg_overrides(b,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(b,est,o,word);
*o++ = 0xA0 + word;
if (b->memregsz == 4) {
*((uint32_t*)o) = (uint32_t)(b->memref_base); o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)(b->memref_base); o += 2;
}
}
else if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x88 + word; o = minx86enc_encode_memreg(a,o,b->reg);
}
else if (b->regtype == MX86_RT_NONE && a->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(b,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(b,est,o,word);
*o++ = 0x8A + word; o = minx86enc_encode_memreg(b,o,a->reg);
}
else if (a->regtype == MX86_RT_SREG && b->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(b,est,o,1);
*o++ = 0x8E; *o++ = (3 << 6) | (a->reg << 3) | b->reg;
}
else if (a->regtype == MX86_RT_SREG && b->regtype == MX86_RT_NONE) {
o = minx86enc_seg_overrides(b,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(b,est,o,1);
*o++ = 0x8E; o = minx86enc_encode_memreg(b,o,a->reg);
}
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_SREG) {
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0x8C; *o++ = (3 << 6) | (b->reg << 3) | a->reg;
}
else if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_SREG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0x8C; o = minx86enc_encode_memreg(a,o,b->reg);
}
/* control regs: apparently there is no valid encoding for mov cr0,r/m or such */
else if (a->regtype == MX86_RT_CR && b->regtype == MX86_RT_REG) {
*o++ = 0x0F; *o++ = 0x22; *o++ = (3 << 6) | (a->reg << 3) | b->reg;
}
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_CR) {
*o++ = 0x0F; *o++ = 0x20; *o++ = (3 << 6) | (b->reg << 3) | a->reg;
}
else if (a->regtype == MX86_RT_DR && b->regtype == MX86_RT_REG) {
*o++ = 0x0F; *o++ = 0x23; *o++ = (3 << 6) | (a->reg << 3) | b->reg;
}
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_DR) {
*o++ = 0x0F; *o++ = 0x21; *o++ = (3 << 6) | (b->reg << 3) | a->reg;
}
else if (a->regtype == MX86_RT_TR && b->regtype == MX86_RT_REG) {
*o++ = 0x0F; *o++ = 0x26; *o++ = (3 << 6) | (a->reg << 3) | b->reg;
}
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_TR) {
*o++ = 0x0F; *o++ = 0x24; *o++ = (3 << 6) | (b->reg << 3) | a->reg;
}
} break;
case MXOP_PUSH: { /*====================PUSH=====================*/
struct minx86dec_argv *a=&ins->argv[0];
if (a->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0x50+a->reg;
}
else if (a->regtype == MX86_RT_NONE) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0xFF; o = minx86enc_encode_memreg(a,o,6);
}
else if (a->regtype == MX86_RT_IMM) {
if (a->value & 0xFFFF0000UL) { /* need 32-bit encoding */
if (!est->data32) *o++ = 0x66;
*o++ = 0x68;
*((uint32_t*)o) = (uint32_t)(a->value); o += 4;
}
else if (a->value & 0xFFFFFF00UL) { /* need 16-bit encoding */
if (est->data32) *o++ = 0x66;
*o++ = 0x68;
*((uint16_t*)o) = (uint16_t)(a->value); o += 2;
}
else {
*o++ = 0x6A; *o++ = (uint8_t)(a->value);
}
}
else if (a->regtype == MX86_RT_SREG) {
switch (a->reg) {
case MX86_SEG_CS: *o++ = 0x0E; break;
case MX86_SEG_DS: *o++ = 0x1E; break;
case MX86_SEG_ES: *o++ = 0x06; break;
case MX86_SEG_FS: *o++ = 0x0F; *o++ = 0xA0; break;
case MX86_SEG_GS: *o++ = 0x0F; *o++ = 0xA8; break;
case MX86_SEG_SS: *o++ = 0x16; break;
}
}
} break;
case MXOP_POP: { /*====================POP=====================*/
struct minx86dec_argv *a=&ins->argv[0];
if (a->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0x58+a->reg;
}
else if (a->regtype == MX86_RT_NONE) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0x8F; o = minx86enc_encode_memreg(a,o,0);
}
else if (a->regtype == MX86_RT_SREG) {
switch (a->reg) {
case MX86_SEG_CS: *o++ = 0x0F; break;
case MX86_SEG_DS: *o++ = 0x1F; break;
case MX86_SEG_ES: *o++ = 0x07; break;
case MX86_SEG_FS: *o++ = 0x0F; *o++ = 0xA1; break;
case MX86_SEG_GS: *o++ = 0x0F; *o++ = 0xA9; break;
case MX86_SEG_SS: *o++ = 0x17; break;
}
}
} break;
case MXOP_INC: { /*====================INC=====================*/
struct minx86dec_argv *a=&ins->argv[0];
unsigned char word = (a->size >= 2) ? 1 : 0;
if (a->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,word);
if (word) {
/* NTS: 32-bit only encoding. This encoding is not valid in x86-64 */
*o++ = 0x40+a->reg;
}
else {
*o++ = 0xFE;
o = minx86enc_encode_rm_reg(a,0/*INC*/,a->reg,o);
}
}
else if (a->regtype == MX86_RT_NONE) {
/* NTS: You must also use this encoding in x86_64, or with BYTE register references */
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0xFE + word; o = minx86enc_encode_memreg(a,o,0);
}
} break;
case MXOP_DEC: { /*====================DEC=====================*/
struct minx86dec_argv *a=&ins->argv[0];
unsigned char word = (a->size >= 2) ? 1 : 0;
if (a->regtype == MX86_RT_REG) {
if (word) {
/* NTS: 32-bit only encoding. This encoding is not valid in x86-64 */
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0x48+a->reg;
}
else {
*o++ = 0xFE;
o = minx86enc_encode_rm_reg(a,1/*DEC*/,a->reg,o);
}
}
else if (a->regtype == MX86_RT_NONE) {
/* NTS: You must also use this encoding in x86_64, or with BYTE register references */
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0xFE + word; o = minx86enc_encode_memreg(a,o,1);
}
} break;
case MXOP_IDIV: { /*====================IDIV=====================*/
struct minx86dec_argv *a=&ins->argv[0];
unsigned char word = (a->size >= 2) ? 1 : 0;
if (a->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0xF6 + word;
o = minx86enc_encode_rm_reg(a,7/*IDIV*/,a->reg,o);
}
else if (a->regtype == MX86_RT_NONE) {
/* NTS: You must also use this encoding in x86_64, or with BYTE register references */
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0xF6 + word; o = minx86enc_encode_memreg(a,o,7);
}
} break;
case MXOP_IMUL: { /*====================IMUL=====================*/
struct minx86dec_argv *a=&ins->argv[0];
unsigned char word = (a->size >= 2) ? 1 : 0;
if (a->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,1);
*o++ = 0xF6 + word;
o = minx86enc_encode_rm_reg(a,5/*IMUL*/,a->reg,o);
}
else if (a->regtype == MX86_RT_NONE) {
/* NTS: You must also use this encoding in x86_64, or with BYTE register references */
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0xF6 + word; o = minx86enc_encode_memreg(a,o,5);
}
} break;
case MXOP_LEA: { /*=====================LEA========================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_NONE) {
o = minx86enc_seg_overrides(b,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(b,est,o,1);
*o++ = 0x8D; o = minx86enc_encode_memreg(b,o,a->reg);
}
} break;
case MXOP_TEST: { /*=====================TEST========================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
unsigned char word = (a->size >= 2) ? 1 : 0;
/* make sure a is r/m and b is reg. ASSUME: both are the same datasize */
/* NTS: TEST only ANDs the two operands together and updates the flags, it doesn't matter the order.
* so most assemblers like NASM will encode the one [mem],reg form no matter what order you put the operands in */
if (b->regtype == MX86_RT_NONE) { struct minx86dec_argv *t = a; a = b; b = t; }
/* TEST [mem],reg or TEST reg,[mem] */
if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x84 + word; o = minx86enc_encode_memreg(a,o,b->reg);
}
/* TEST reg,reg or TEST reg,reg */
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x84 + word; o = minx86enc_encode_rm_reg(b,b->reg,a->reg,o);
}
/* CMP reg/rm,imm */
else if ((a->regtype == MX86_RT_NONE || a->regtype == MX86_RT_REG) && b->regtype == MX86_RT_IMM) {
if (a->regtype == MX86_RT_NONE) o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
if (a->regtype == MX86_RT_REG && a->reg == MX86_REG_EAX) {
*o++ = 0xA8 + (word&1);
}
else {
*o++ = 0xF6 + (word&1);
if (a->regtype == MX86_RT_REG)
o = minx86enc_encode_rm_reg(a,0,a->reg,o);
else
o = minx86enc_encode_memreg(a,o,0);
}
if (!word) {
*o++ = (unsigned char)(b->value);
}
else {
if (a->size == 4) {
*((uint32_t*)o) = (uint32_t)b->value; o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)b->value; o += 2;
}
}
}
} break;
case MXOP_OR: { /*=====================OR========================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
unsigned char word = (a->size >= 2) ? 1 : 0;
/* lock prefix */
if (ins->lock) *o++ = 0xF0;
/* make sure a is r/m and b is reg. ASSUME: both are the same datasize */
if (b->regtype == MX86_RT_NONE) { struct minx86dec_argv *t = a; a = b; b = t; word += 2; }
/* ADD [mem],reg or ADD reg,[mem] */
if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x08 + word; o = minx86enc_encode_memreg(a,o,b->reg);
}
/* TEST reg,reg or TEST reg,reg */
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x08 + word; o = minx86enc_encode_rm_reg(b,b->reg,a->reg,o);
}
/* CMP reg/rm,imm */
else if ((a->regtype == MX86_RT_NONE || a->regtype == MX86_RT_REG) && b->regtype == MX86_RT_IMM) {
unsigned char shorthand = 0;
if (a->regtype == MX86_RT_NONE) o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
if (word && (b->value >= 0xFFFFFF80 || (b->value >= 0xFF80 && a->size == 2) || b->value < 0x80)) shorthand = 2;
if (a->regtype == MX86_RT_REG && a->reg == MX86_REG_EAX && !shorthand) {
*o++ = 0x0C + (word&1);
}
else {
*o++ = 0x80 + (word&1) + shorthand;
if (a->regtype == MX86_RT_REG)
o = minx86enc_encode_rm_reg(a,1,a->reg,o);
else
o = minx86enc_encode_memreg(a,o,1);
}
if (shorthand || !word) {
*o++ = (unsigned char)(b->value);
}
else {
if (a->size == 4) {
*((uint32_t*)o) = (uint32_t)b->value; o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)b->value; o += 2;
}
}
}
} break;
case MXOP_ADD: { /*=====================ADD========================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
unsigned char word = (a->size >= 2) ? 1 : 0;
/* lock prefix */
if (ins->lock) *o++ = 0xF0;
/* make sure a is r/m and b is reg. ASSUME: both are the same datasize */
if (b->regtype == MX86_RT_NONE) { struct minx86dec_argv *t = a; a = b; b = t; word += 2; }
/* ADD [mem],reg or ADD reg,[mem] */
if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x00 + word; o = minx86enc_encode_memreg(a,o,b->reg);
}
/* TEST reg,reg or TEST reg,reg */
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x00 + word; o = minx86enc_encode_rm_reg(b,b->reg,a->reg,o);
}
/* CMP reg/rm,imm */
else if ((a->regtype == MX86_RT_NONE || a->regtype == MX86_RT_REG) && b->regtype == MX86_RT_IMM) {
unsigned char shorthand = 0;
if (a->regtype == MX86_RT_NONE) o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
if (word && (b->value >= 0xFFFFFF80 || (b->value >= 0xFF80 && a->size == 2) || b->value < 0x80)) shorthand = 2;
if (a->regtype == MX86_RT_REG && a->reg == MX86_REG_EAX && !shorthand) {
*o++ = 0x04 + (word&1);
}
else {
*o++ = 0x80 + (word&1) + shorthand;
if (a->regtype == MX86_RT_REG)
o = minx86enc_encode_rm_reg(a,0,a->reg,o);
else
o = minx86enc_encode_memreg(a,o,0);
}
if (shorthand || !word) {
*o++ = (unsigned char)(b->value);
}
else {
if (a->size == 4) {
*((uint32_t*)o) = (uint32_t)b->value; o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)b->value; o += 2;
}
}
}
} break;
case MXOP_ADC: { /*=====================ADC========================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
unsigned char word = (a->size >= 2) ? 1 : 0;
/* make sure a is r/m and b is reg. ASSUME: both are the same datasize */
if (b->regtype == MX86_RT_NONE) { struct minx86dec_argv *t = a; a = b; b = t; word += 2; }
/* ADD [mem],reg or ADD reg,[mem] */
if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x10 + word; o = minx86enc_encode_memreg(a,o,b->reg);
}
/* TEST reg,reg or TEST reg,reg */
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x10 + word; o = minx86enc_encode_rm_reg(b,b->reg,a->reg,o);
}
/* CMP reg/rm,imm */
else if ((a->regtype == MX86_RT_NONE || a->regtype == MX86_RT_REG) && b->regtype == MX86_RT_IMM) {
unsigned char shorthand = 0;
if (a->regtype == MX86_RT_NONE) o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
if (word && (b->value >= 0xFFFFFF80 || (b->value >= 0xFF80 && a->size == 2) || b->value < 0x80)) shorthand = 2;
if (a->regtype == MX86_RT_REG && a->reg == MX86_REG_EAX && !shorthand) {
*o++ = 0x14 + (word&1);
}
else {
*o++ = 0x80 + (word&1) + shorthand;
if (a->regtype == MX86_RT_REG)
o = minx86enc_encode_rm_reg(a,2,a->reg,o);
else
o = minx86enc_encode_memreg(a,o,2);
}
if (shorthand || !word) {
*o++ = (unsigned char)(b->value);
}
else {
if (a->size == 4) {
*((uint32_t*)o) = (uint32_t)b->value; o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)b->value; o += 2;
}
}
}
} break;
case MXOP_AND: { /*=====================AND========================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
unsigned char word = (a->size >= 2) ? 1 : 0;
/* make sure a is r/m and b is reg. ASSUME: both are the same datasize */
if (b->regtype == MX86_RT_NONE) { struct minx86dec_argv *t = a; a = b; b = t; word += 2; }
/* ADD [mem],reg or ADD reg,[mem] */
if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x20 + word; o = minx86enc_encode_memreg(a,o,b->reg);
}
/* TEST reg,reg or TEST reg,reg */
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x20 + word; o = minx86enc_encode_rm_reg(b,b->reg,a->reg,o);
}
/* CMP reg/rm,imm */
else if ((a->regtype == MX86_RT_NONE || a->regtype == MX86_RT_REG) && b->regtype == MX86_RT_IMM) {
unsigned char shorthand = 0;
if (a->regtype == MX86_RT_NONE) o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
if (word && (b->value >= 0xFFFFFF80 || (b->value >= 0xFF80 && a->size == 2) || b->value < 0x80)) shorthand = 2;
if (a->regtype == MX86_RT_REG && a->reg == MX86_REG_EAX && !shorthand) {
*o++ = 0x24 + (word&1);
}
else {
*o++ = 0x80 + (word&1) + shorthand;
if (a->regtype == MX86_RT_REG)
o = minx86enc_encode_rm_reg(a,4,a->reg,o);
else
o = minx86enc_encode_memreg(a,o,4);
}
if (shorthand || !word) {
*o++ = (unsigned char)(b->value);
}
else {
if (a->size == 4) {
*((uint32_t*)o) = (uint32_t)b->value; o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)b->value; o += 2;
}
}
}
} break;
case MXOP_CMP: { /*=====================CMP========================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
unsigned char word = (a->size >= 2) ? 1 : 0;
/* make sure a is r/m and b is reg. ASSUME: both are the same datasize */
if (b->regtype == MX86_RT_NONE) { struct minx86dec_argv *t = a; a = b; b = t; word += 2; }
/* ADD [mem],reg or ADD reg,[mem] */
if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x38 + word; o = minx86enc_encode_memreg(a,o,b->reg);
}
/* TEST reg,reg or TEST reg,reg */
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x38 + word; o = minx86enc_encode_rm_reg(b,b->reg,a->reg,o);
}
/* CMP reg/rm,imm */
else if ((a->regtype == MX86_RT_NONE || a->regtype == MX86_RT_REG) && b->regtype == MX86_RT_IMM) {
unsigned char shorthand = 0;
if (a->regtype == MX86_RT_NONE) o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
if (word && (b->value >= 0xFFFFFF80 || (b->value >= 0xFF80 && a->size == 2) || b->value < 0x80)) shorthand = 2;
if (a->regtype == MX86_RT_REG && a->reg == MX86_REG_EAX && !shorthand) {
*o++ = 0x3C + (word&1);
}
else {
*o++ = 0x80 + (word&1) + shorthand;
if (a->regtype == MX86_RT_REG)
o = minx86enc_encode_rm_reg(a,7,a->reg,o);
else
o = minx86enc_encode_memreg(a,o,7);
}
if (shorthand || !word) {
*o++ = (unsigned char)(b->value);
}
else {
if (a->size == 4) {
*((uint32_t*)o) = (uint32_t)b->value; o += 4;
}
else {
*((uint16_t*)o) = (uint16_t)b->value; o += 2;
}
}
}
} break;
case MXOP_SBB: { /*=====================SBB========================*/
struct minx86dec_argv *a=&ins->argv[0],*b=&ins->argv[1];
unsigned char word = (a->size >= 2) ? 1 : 0;
/* make sure a is r/m and b is reg. ASSUME: both are the same datasize */
if (b->regtype == MX86_RT_NONE) { struct minx86dec_argv *t = a; a = b; b = t; word += 2; }
/* ADD [mem],reg or ADD reg,[mem] */
if (a->regtype == MX86_RT_NONE && b->regtype == MX86_RT_REG) {
o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x18 + word; o = minx86enc_encode_memreg(a,o,b->reg);
}
/* TEST reg,reg or TEST reg,reg */
else if (a->regtype == MX86_RT_REG && b->regtype == MX86_RT_REG) {
o = minx86enc_32_overrides(a,est,o,word);
*o++ = 0x18 + word; o = minx86enc_encode_rm_reg(b,b->reg,a->reg,o);
}
/* CMP reg/rm,imm */
else if ((a->regtype == MX86_RT_NONE || a->regtype == MX86_RT_REG) && b->regtype == MX86_RT_IMM) {
unsigned char shorthand = 0;
if (a->regtype == MX86_RT_NONE) o = minx86enc_seg_overrides(a,est,o,ins->segment >= 0);
o = minx86enc_32_overrides(a,est,o,word);
if (word && (b->value >= 0xFFFFFF80 || (b->value >= 0xFF80 && a->size == 2) || b->value < 0x80)) shorthand = 2;
if (a->regtype == MX86_RT_REG && a->reg == MX86_REG_EAX && !shorthand) {
*o++ = 0x1C + (word&1);
}
else {
*o++ = 0x80 + (word&1) + shorthand;
if (a->regtype == MX86_RT_REG)
o = minx86enc_encode_rm_reg(a,3,a->reg,o);
else
o = minx86enc_encode_memreg(a,o,3);
}