Improved function names

src/build/arch/x64/regReg.go

@@ -0,0 +1,29 @@
+package x64
+
+// regReg encodes an operation using 2 registers.
+func regReg(code []byte, reg byte, rm byte, opCodes ...byte) []byte {
+	w := byte(1)      // Indicates a 64-bit register.
+	r := byte(0)      // Extension to the "reg" field in ModRM.
+	x := byte(0)      // Extension to the SIB index field.
+	b := byte(0)      // Extension to the "rm" field in ModRM or the SIB base (r8 up to r15 use this).
+	mod := byte(0b11) // Direct addressing mode, no register offsets.
+
+	if reg > 0b111 {
+		r = 1
+		reg &= 0b111
+	}
+
+	if rm > 0b111 {
+		b = 1
+		rm &= 0b111
+	}
+
+	rex := REX(w, r, x, b)
+	modRM := ModRM(mod, reg, rm)
+
+	code = append(code, rex)
+	code = append(code, opCodes...)
+	code = append(code, modRM)
+
+	return code
+}