Implemented compilation to SSA form

src/ssa/Value.go

@@ -0,0 +1,83 @@
+package ssa
+
+import (
+	"fmt"
+
+	"git.urbach.dev/cli/q/src/cpu"
+)
+
+// Value is a single instruction in a basic block.
+// It is implemented as a "fat struct" for performance reasons.
+// It contains all the fields necessary to represent all instruction types.
+type Value struct {
+	Args     []*Value
+	Int      int
+	Text     string
+	Register cpu.Register
+	Type     Type
+}
+
+// Equals returns true if the values are equal.
+func (a Value) Equals(b Value) bool {
+	if a.Type != b.Type {
+		return false
+	}
+
+	if a.Int != b.Int {
+		return false
+	}
+
+	if a.Text != b.Text {
+		return false
+	}
+
+	if a.Register != b.Register {
+		return false
+	}
+
+	if len(a.Args) != len(b.Args) {
+		return false
+	}
+
+	for i := range a.Args {
+		if !a.Args[i].Equals(*b.Args[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
+// IsConst returns true if the value is constant.
+func (i *Value) IsConst() bool {
+	switch i.Type {
+	case Func, Int, Register, String:
+		return true
+	default:
+		return false
+	}
+}
+
+// String returns a human-readable representation of the instruction.
+func (i *Value) String() string {
+	switch i.Type {
+	case Func:
+		return i.Text
+	case Int:
+		return fmt.Sprintf("%d", i.Int)
+	case Register:
+		return i.Register.String()
+	case String:
+		return fmt.Sprintf("\"%s\"", i.Text)
+	case Add:
+		return fmt.Sprintf("%s + %s", i.Args[0], i.Args[1])
+	case Return:
+		return fmt.Sprintf("return %s", i.Args[0])
+	case Call:
+		return fmt.Sprintf("call%v", i.Args)
+	case Syscall:
+		return fmt.Sprintf("syscall%v", i.Args)
+	default:
+		return ""
+	}
+}