Added x86 package

src/x86/Jump_test.go

@@ -0,0 +1,40 @@
+package x86_test
+
+import (
+	"testing"
+
+	"git.urbach.dev/cli/q/src/x86"
+	"git.urbach.dev/go/assert"
+)
+
+func TestJump(t *testing.T) {
+	usagePatterns := []struct {
+		Offset int8
+		Code   []byte
+	}{
+		{0, []byte{0xEB, 0x00}},
+		{1, []byte{0xEB, 0x01}},
+		{2, []byte{0xEB, 0x02}},
+		{3, []byte{0xEB, 0x03}},
+		{127, []byte{0xEB, 0x7F}},
+		{-1, []byte{0xEB, 0xFF}},
+		{-2, []byte{0xEB, 0xFE}},
+		{-3, []byte{0xEB, 0xFD}},
+		{-128, []byte{0xEB, 0x80}},
+	}
+
+	for _, pattern := range usagePatterns {
+		t.Logf("jmp %x", pattern.Offset)
+		code := x86.Jump8(nil, pattern.Offset)
+		assert.DeepEqual(t, code, pattern.Code)
+	}
+}
+
+func TestConditionalJump(t *testing.T) {
+	assert.DeepEqual(t, x86.Jump8IfEqual(nil, 1), []byte{0x74, 0x01})
+	assert.DeepEqual(t, x86.Jump8IfNotEqual(nil, 1), []byte{0x75, 0x01})
+	assert.DeepEqual(t, x86.Jump8IfLess(nil, 1), []byte{0x7C, 0x01})
+	assert.DeepEqual(t, x86.Jump8IfGreaterOrEqual(nil, 1), []byte{0x7D, 0x01})
+	assert.DeepEqual(t, x86.Jump8IfLessOrEqual(nil, 1), []byte{0x7E, 0x01})
+	assert.DeepEqual(t, x86.Jump8IfGreater(nil, 1), []byte{0x7F, 0x01})
+}