void Assembler::lea(Indirect mem, Register reg) {
int mem_idx = mem.base.regnum;
int reg_idx = reg.regnum;
int rex = REX_W;
if (mem_idx >= 8) {
rex |= REX_B;
mem_idx -= 8;
}
if (reg_idx >= 8) {
rex |= REX_R;
reg_idx -= 8;
}
assert(mem_idx >= 0 && mem_idx < 8);
assert(reg_idx >= 0 && reg_idx < 8);
emitRex(rex);
emitByte(0x8D);
bool needssib = (mem_idx == 0b100);
int mode = getModeFromOffset(mem.offset);
emitModRM(mode, reg_idx, mem_idx);
if (needssib)
emitSIB(0b00, 0b100, mem_idx);
if (mode == 0b01) {
emitByte(mem.offset);
} else if (mode == 0b10) {
assert((-1L << 31) <= mem.offset && mem.offset < (1L << 31) - 1);
emitInt(mem.offset, 4);
}
}
void Assembler::movsd(XMMRegister src, Indirect dest) {
int rex = 0;
int src_idx = src.regnum;
int dest_idx = dest.base.regnum;
if (src_idx >= 8) {
rex |= REX_R;
src_idx -= 8;
}
if (dest_idx >= 8) {
trap();
rex |= REX_B;
dest_idx -= 8;
}
emitByte(0xf2);
if (rex)
emitRex(rex);
emitByte(0x0f);
emitByte(0x11);
bool needssib = (dest_idx == 0b100);
int mode = getModeFromOffset(dest.offset);
emitModRM(mode, src_idx, dest_idx);
if (needssib)
emitSIB(0b00, 0b100, dest_idx);
if (mode == 0b01) {
emitByte(dest.offset);
} else if (mode == 0b10) {
emitInt(dest.offset, 4);
}
}
void Assembler::movq(Immediate src, Indirect dest) {
int64_t src_val = src.val;
assert((-1L << 31) <= src_val && src_val < (1L << 31) - 1);
int rex = REX_W;
int dest_idx = dest.base.regnum;
if (dest_idx >= 8) {
rex |= REX_B;
dest_idx -= 8;
}
emitRex(rex);
emitByte(0xc7);
bool needssib = (dest_idx == 0b100);
int mode = getModeFromOffset(dest.offset);
emitModRM(mode, 0, dest_idx);
if (needssib)
emitSIB(0b00, 0b100, dest_idx);
if (mode == 0b01) {
emitByte(dest.offset);
} else if (mode == 0b10) {
emitInt(dest.offset, 4);
}
emitInt(src_val, 4);
}
void Assembler::mov(Register src, Indirect dest) {
int rex = REX_W;
int src_idx = src.regnum;
int dest_idx = dest.base.regnum;
assert(src_idx != dest_idx && "while valid this is almost certainly a register allocator bug");
if (src_idx >= 8) {
rex |= REX_R;
src_idx -= 8;
}
if (dest_idx >= 8) {
rex |= REX_B;
dest_idx -= 8;
}
emitRex(rex);
emitByte(0x89);
bool needssib = (dest_idx == 0b100);
int mode = getModeFromOffset(dest.offset);
emitModRM(mode, src_idx, dest_idx);
if (needssib)
emitSIB(0b00, 0b100, dest_idx);
if (mode == 0b01) {
emitByte(dest.offset);
} else if (mode == 0b10) {
emitInt(dest.offset, 4);
}
}
void Assembler::emitArith(Immediate imm, Indirect mem, int opcode) {
int64_t amount = imm.val;
assert(fitsInto<int32_t>(amount));
assert(0 <= opcode && opcode < 8);
int rex = REX_W;
int mem_idx = mem.base.regnum;
if (mem_idx >= 8) {
rex |= REX_B;
mem_idx -= 8;
}
emitRex(rex);
bool needssib = (mem_idx == 0b100);
assert(!needssib && "untested");
int mode = getModeFromOffset(mem.offset, mem_idx);
assert(mode != 0b10 && "not yet supported");
if (-0x80 <= amount && amount < 0x80) {
emitByte(0x83);
if (needssib)
emitSIB(0b00, 0b100, mem_idx);
emitModRM(mode, opcode, mem_idx);
if (mode == 0b01)
emitByte(mem.offset);
emitByte(amount);
} else {
emitByte(0x81);
if (needssib)
emitSIB(0b00, 0b100, mem_idx);
emitModRM(mode, opcode, mem_idx);
if (mode == 0b01)
emitByte(mem.offset);
emitInt(amount, 4);
}
}
