Flattened package hierarchy

src/x64/Move.go

@@ -0,0 +1,60 @@
+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)
+}