Added more tests

src/arm/Sub_test.go

@@ -0,0 +1,26 @@
+package arm_test
+
+import (
+	"testing"
+
+	"git.urbach.dev/cli/q/src/arm"
+	"git.urbach.dev/cli/q/src/cpu"
+	"git.urbach.dev/go/assert"
+)
+
+func TestSubRegisterNumber(t *testing.T) {
+	usagePatterns := []struct {
+		Destination cpu.Register
+		Source      cpu.Register
+		Number      int
+		Code        uint32
+	}{
+		{arm.X0, arm.X0, 1, 0xD1000400},
+	}
+
+	for _, pattern := range usagePatterns {
+		t.Logf("sub %s, %s, %d", pattern.Destination, pattern.Source, pattern.Number)
+		code := arm.SubRegisterNumber(pattern.Destination, pattern.Source, pattern.Number)
+		assert.DeepEqual(t, code, pattern.Code)
+	}
+}