operand: const types

operand/checks.go

@@ -1,8 +1,6 @@
 package operand
 
 import (
-	"math"
-
 	"github.com/mmcloughlin/avo/reg"
 )
 
@@ -14,53 +12,50 @@ func IsRegister(op Op) bool { _, ok := op.(reg.Register); return ok }
 // IsMem returns whether op has type Mem.
 func IsMem(op Op) bool { _, ok := op.(Mem); return ok }
 
-// IsImm returns whether op has type Imm.
-func IsImm(op Op) bool { _, ok := op.(Imm); return ok }
-
 // IsRel returns whether op has type Rel.
 func IsRel(op Op) bool { _, ok := op.(Rel); return ok }
 
 // Checks corresponding to specific operand types in the Intel Manual:
 
 // Is1 returns true if op is the immediate constant 1.
 func Is1(op Op) bool {
-	i, ok := op.(Imm)
+	i, ok := op.(U8)
 	return ok && i == 1
 }
 
 // Is3 returns true if op is the immediate constant 3.
 func Is3(op Op) bool {
-	i, ok := op.(Imm)
+	i, ok := op.(U8)
 	return ok && i == 3
 }
 
 // IsImm2u returns true if op is a 2-bit unsigned immediate (less than 4).
 func IsImm2u(op Op) bool {
-	i, ok := op.(Imm)
+	i, ok := op.(U8)
 	return ok && i < 4
 }
 
 // IsImm8 returns true is op is an 8-bit immediate.
 func IsImm8(op Op) bool {
-	i, ok := op.(Imm)
-	return ok && i <= math.MaxUint8
+	_, ok := op.(U8)
+	return ok
 }
 
 // IsImm16 returns true is op is a 16-bit immediate.
 func IsImm16(op Op) bool {
-	i, ok := op.(Imm)
-	return ok && i <= math.MaxUint16
+	_, ok := op.(U16)
+	return ok
 }
 
 // IsImm32 returns true is op is a 32-bit immediate.
 func IsImm32(op Op) bool {
-	i, ok := op.(Imm)
-	return ok && i <= math.MaxUint32
+	_, ok := op.(U32)
+	return ok
 }
 
 // IsImm64 returns true is op is a 64-bit immediate.
 func IsImm64(op Op) bool {
-	_, ok := op.(Imm)
+	_, ok := op.(U64)
 	return ok
 }
 

operand/const.go

@@ -0,0 +1,32 @@
+package operand
+
+import "fmt"
+
+type Constant interface {
+	Op
+	Bytes() int
+	constant()
+}
+
+//go:generate go run make_const.go -output zconst.go
+
+// String is a string constant.
+type String string
+
+func (s String) Asm() string { return fmt.Sprintf("$%q", s) }
+func (s String) Bytes() int  { return len(s) }
+func (s String) constant()   {}
+
+// Imm returns an unsigned integer constant with size guessed from x.
+func Imm(x uint64) Constant {
+	// TODO(mbm): remove this function
+	switch {
+	case uint64(uint8(x)) == x:
+		return U8(x)
+	case uint64(uint16(x)) == x:
+		return U16(x)
+	case uint64(uint32(x)) == x:
+		return U32(x)
+	}
+	return U64(x)
+}

operand/const_test.go

@@ -0,0 +1,32 @@
+package operand
+
+import "testing"
+
+func TestConstants(t *testing.T) {
+	cases := []struct {
+		Const Constant
+		Asm   string
+		Bytes int
+	}{
+		{F32(3.1415), "$(3.1415)", 4},
+		{F64(3.1415), "$(3.1415)", 8},
+		{U8(42), "$0x2a", 1},
+		{U16(42), "$0x002a", 2},
+		{U32(42), "$0x0000002a", 4},
+		{U64(42), "$0x000000000000002a", 8},
+		{I8(-42), "$-42", 1},
+		{I16(-42), "$-42", 2},
+		{I32(-42), "$-42", 4},
+		{I64(-42), "$-42", 8},
+		{String("hello"), "$\"hello\"", 5},
+		{String("quot:\"q\""), "$\"quot:\\\"q\\\"\"", 8},
+	}
+	for _, c := range cases {
+		if c.Const.Asm() != c.Asm {
+			t.Errorf("%v.Asm() = %v; expect %v", c.Const, c.Const.Asm(), c.Asm)
+		}
+		if c.Const.Bytes() != c.Bytes {
+			t.Errorf("%v.Bytes() = %v; expect %v", c.Const, c.Const.Bytes(), c.Bytes)
+		}
+	}
+}

operand/make_const.go

@@ -0,0 +1,75 @@
+// +build ignore
+
+package main
+
+import (
+	"bytes"
+	"flag"
+	"fmt"
+	"go/format"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strconv"
+)
+
+var (
+	output = flag.String("output", "", "path to output file (default stdout)")
+)
+
+func PrintConstType(w io.Writer, name, typ, format string, size int, doc string) {
+	r := typ[0]
+	fmt.Fprintf(w, "// %s\n", doc)
+	fmt.Fprintf(w, "type %s %s\n", name, typ)
+	fmt.Fprintf(w, "\n")
+	fmt.Fprintf(w, "func (%c %s) Asm() string { return fmt.Sprintf(\"$%s\", %c) }\n", r, name, format, r)
+	fmt.Fprintf(w, "func (%c %s) Bytes() int  { return %d }\n", r, name, size)
+	fmt.Fprintf(w, "func (%c %s) constant()   {}\n", r, name)
+	fmt.Fprintf(w, "\n")
+}
+
+func PrintConstTypes(w io.Writer) {
+	_, self, _, _ := runtime.Caller(0)
+	fmt.Fprintf(w, "// Code generated by %s. DO NOT EDIT.\n\n", filepath.Base(self))
+	fmt.Fprintf(w, "package operand\n\n")
+	fmt.Fprintf(w, "import \"fmt\"\n\n")
+	for n := 1; n <= 8; n *= 2 {
+		bits := n * 8
+		bs := strconv.Itoa(bits)
+
+		if n >= 4 {
+			PrintConstType(w, "F"+bs, "float"+bs, "(%#v)", n, fmt.Sprintf("F%d is a %d-bit floating point constant.", bits, bits))
+		}
+		PrintConstType(w, "I"+bs, "int"+bs, "%+d", n, fmt.Sprintf("I%d is a %d-bit signed integer constant.", bits, bits))
+		PrintConstType(w, "U"+bs, "uint"+bs, "%#0"+strconv.Itoa(2*n)+"x", n, fmt.Sprintf("U%d is a %d-bit unsigned integer constant.", bits, bits))
+	}
+}
+
+func main() {
+	flag.Parse()
+
+	w := os.Stdout
+	if *output != "" {
+		f, err := os.Create(*output)
+		if err != nil {
+			log.Fatal(err)
+		}
+		defer f.Close()
+		w = f
+	}
+
+	buf := bytes.NewBuffer(nil)
+	PrintConstTypes(buf)
+
+	src, err := format.Source(buf.Bytes())
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	_, err = w.Write(src)
+	if err != nil {
+		log.Fatal(err)
+	}
+}

operand/types.go

@@ -75,12 +75,6 @@ func (m Mem) Asm() string {
 	return a
 }
 
-type Imm uint64
-
-func (i Imm) Asm() string {
-	return fmt.Sprintf("$%#x", i)
-}
-
 // Rel is an offset relative to the instruction pointer.
 type Rel int32
 
@@ -109,7 +103,7 @@ func Registers(op Op) []reg.Register {
 			r = append(r, op.Index)
 		}
 		return r
-	case Imm, Rel, LabelRef:
+	case Constant, Rel, LabelRef:
 		return nil
 	}
 	panic("unknown operand type")

pass/reg_test.go

@@ -18,8 +18,8 @@ func TestLivenessBasic(t *testing.T) {
 	ctx.Function("add")
 	a := ctx.GP64v()
 	b := ctx.GP64v()
-	ctx.MOVQ(operand.Imm(1), a)
-	ctx.MOVQ(operand.Imm(2), b)
+	ctx.MOVQ(operand.U64(1), a)
+	ctx.MOVQ(operand.U64(2), b)
 	ctx.ADDQ(a, b)
 
 	AssertLiveness(t, ctx,