q/src/x64/Move.go

61 lines
1.4 KiB
Go

package x64
import (
"encoding/binary"
"git.akyoto.dev/cli/q/src/cpu"
"git.akyoto.dev/cli/q/src/sizeof"
)
// MoveRegisterNumber moves an integer into the given register.
func MoveRegisterNumber(code []byte, destination cpu.Register, number int) []byte {
w := byte(0)
if sizeof.Signed(int64(number)) == 8 {
w = 1
}
if w == 0 && number < 0 {
return MoveRegisterNumber32(code, destination, number)
}
b := byte(0)
if destination > 0b111 {
b = 1
destination &= 0b111
}
if w != 0 || b != 0 {
code = append(code, REX(w, 0, 0, b))
}
code = append(code, 0xB8+byte(destination))
if w == 1 {
return binary.LittleEndian.AppendUint64(code, uint64(number))
} else {
return binary.LittleEndian.AppendUint32(code, uint32(number))
}
}
// MoveRegisterNumber32 moves an integer into the given register and sign-extends the register.
func MoveRegisterNumber32(code []byte, destination cpu.Register, number int) []byte {
b := byte(0)
if destination > 0b111 {
b = 1
destination &= 0b111
}
code = append(code, REX(1, 0, 0, b))
code = append(code, 0xC7)
code = append(code, ModRM(AddressDirect, 0, byte(destination)))
return binary.LittleEndian.AppendUint32(code, uint32(number))
}
// MoveRegisterRegister moves a register value into another register.
func MoveRegisterRegister(code []byte, destination cpu.Register, source cpu.Register) []byte {
return encode(code, AddressDirect, source, destination, 8, 0x89)
}