Improved build performance

src/x64/Call.go

@@ -0,0 +1,14 @@
+package x64
+
+// Call places the return address on the top of the stack and continues
+// program flow at the new address. The address is relative to the next instruction.
+func Call(code []byte, address uint32) []byte {
+	return append(
+		code,
+		0xe8,
+		byte(address),
+		byte(address>>8),
+		byte(address>>16),
+		byte(address>>24),
+	)
+}

src/x64/Move.go

@@ -0,0 +1,13 @@
+package x64
+
+// MoveRegNum32 moves a 32 bit integer into the given register.
+func MoveRegNum32(code []byte, register uint8, number uint32) []byte {
+	return append(
+		code,
+		0xb8+register,
+		byte(number),
+		byte(number>>8),
+		byte(number>>16),
+		byte(number>>24),
+	)
+}

src/x64/Return.go

@@ -0,0 +1,7 @@
+package x64
+
+// Return transfers program control to a return address located on the top of the stack.
+// The address is usually placed on the stack by a Call instruction.
+func Return(code []byte) []byte {
+	return append(code, 0xc3)
+}

src/x64/Syscall.go

@@ -0,0 +1,6 @@
+package x64
+
+// Syscall is the primary way to communicate with the OS kernel.
+func Syscall(code []byte) []byte {
+	return append(code, 0x0f, 0x05)
+}