new

Change-Id: I9107ab7d0cbb6e05b6c87951cb143ce6a2e67b01

src/hash/maphash/maphash.go

@@ -359,26 +359,11 @@ func appendT(h *Hash, v reflect.Value) {
 		return
 	case reflect.Complex64, reflect.Complex128:
 		c := v.Complex()
-		var buf [8]byte
-		byteorder.LePutUint64(buf[:], math.Float64bits(real(c)))
-		h.Write(buf[:])
-		byteorder.LePutUint64(buf[:], math.Float64bits(imag(c)))
-		h.Write(buf[:])
+		h.float64(real(c))
+		h.float64(imag(c))
 		return
 	case reflect.Float32, reflect.Float64:
-		f := v.Float()
-		if f == 0 {
-			h.WriteByte(0)
-			return
-		}
-		var buf [8]byte
-		if f != f {
-			byteorder.LePutUint64(buf[:], randUint64())
-			h.Write(buf[:])
-			return
-		}
-		byteorder.LePutUint64(buf[:], math.Float64bits(f))
-		h.Write(buf[:])
+		h.float64(v.Float())
 		return
 	case reflect.Bool:
 		h.WriteByte(btoi(v.Bool()))
@@ -395,6 +380,22 @@ func appendT(h *Hash, v reflect.Value) {
 	panic(fmt.Errorf("hash/maphash: %s not comparable", v.Type().String()))
 }
 
+func (h *Hash) float64(f float64) {
+	if f == 0 {
+		h.WriteByte(0)
+		return
+	}
+	var buf [8]byte
+	if f != f {
+		byteorder.LePutUint64(buf[:], randUint64())
+		h.Write(buf[:])
+		return
+	}
+	byteorder.LePutUint64(buf[:], math.Float64bits(f))
+	h.Write(buf[:])
+	return
+}
+
 func btoi(b bool) byte {
 	if b {
 		return 1

src/hash/maphash/maphash_purego.go

@@ -94,8 +94,6 @@ func mix(a, b uint64) uint64 {
 	return hi ^ lo
 }
 
-var strTyp = reflect.TypeFor[string]()
-
 func comparableF[T comparable](h *Hash, v T) {
 	vv := reflect.ValueOf(v)
 	appendT(h, vv)

src/hash/maphash/maphash_runtime.go

@@ -48,21 +48,15 @@ func comparableF[T comparable](h *Hash, v T) {
 	t := abi.TypeFor[T]()
 	ptr := unsafe.Pointer(&v)
 	l := t.Size()
-	k := t.Kind()
-	if k == abi.String {
-		s := ((*string)(ptr))
-		h.WriteString(*s)
+	if t.TFlag&abi.TFlagRegularMemory != 0 {
+		h.Write(unsafe.Slice((*byte)(ptr), l))
 		return
 	}
-	if t.TFlag&abi.TFlagRegularMemory == 0 {
-		// Note: if T like struct {s string}
-		// str value equal but ptr not equal,
-		// if think of it as a contiguous piece of memory,
-		// hash it, that happen v1 == v2
-		// Comparable(s, v1) != Comparable(s, v2).
-		vv := reflect.ValueOf(v)
-		appendT(h, vv)
-		return
-	}
-	h.Write(unsafe.Slice((*byte)(ptr), l))
+	// Note: if T like struct {s string}
+	// str value equal but ptr not equal,
+	// if think of it as a contiguous piece of memory,
+	// hash it, that happen v1 == v2
+	// Comparable(s, v1) != Comparable(s, v2).
+	vv := reflect.ValueOf(v)
+	appendT(h, vv)
 }

src/hash/maphash/maphash_test.go

@@ -227,13 +227,19 @@ func TestComparable(t *testing.T) {
 	testComparable(t, uintptr(12))
 	testComparable(t, any("s"))
 	testComparable(t, "s")
+	testComparable(t, true)
 	testComparable(t, new(float64))
 	testComparable(t, float64(9))
 	testComparable(t, complex128(9i+1))
+	testComparable(t, struct{}{})
 	testComparable(t, struct {
 		i int
+		u uint
+		b bool
 		f float64
-	}{i: 9, f: 9.9})
+		p *int
+		a any
+	}{i: 9, u: 1, b: true, f: 9.9, p: new(int), a: 1})
 	type S struct {
 		s string
 	}
@@ -246,11 +252,21 @@ func TestComparable(t *testing.T) {
 		t.Fatalf("unexpected two heapStr value not equal")
 	}
 	testComparable(t, s1, s2)
+	testComparable(t, s1.s, s2.s)
 	testComparable(t, float32(0), negativeZero[float32]())
 	testComparable(t, float64(0), negativeZero[float64]())
+	testComparableNoEqual(t, math.NaN(), math.NaN())
+	testComparableNoEqual(t, [2]string{"a", ""}, [2]string{"", "a"})
+	testComparableNoEqual(t, any(struct{ x int }{x: 1}), any(struct {
+		x int
+		s string
+	}{x: 1}))
+}
+
+func testComparableNoEqual[T comparable](t *testing.T, v1, v2 T) {
 	seed := MakeSeed()
-	if Comparable(seed, math.NaN()) == Comparable(seed, math.NaN()) {
-		t.Fatalf("Comparable(seed, NaN) == Comparable(seed, NaN)")
+	if Comparable(seed, v1) == Comparable(seed, v2) {
+		t.Fatalf("Comparable(seed, %v) == Comparable(seed, %v)", v1, v2)
 	}
 }
 
@@ -291,13 +307,17 @@ func testComparable[T comparable](t *testing.T, v T, v2 ...T) {
 	})
 }
 
+var use byte
+
 //go:noinline
 func stackGrow(dep int) {
 	if dep == 0 {
 		return
 	}
 	var local [1024]byte
-	_ = local
+	// make sure local is allocated on the stack.
+	local[randUint64()%1024] = byte(randUint64())
+	use = local[randUint64()%1024]
 	stackGrow(dep - 1)
 }
 
@@ -307,13 +327,19 @@ func TestWriteComparable(t *testing.T) {
 	testWriteComparable(t, uintptr(12))
 	testWriteComparable(t, any("s"))
 	testWriteComparable(t, "s")
+	testComparable(t, true)
 	testWriteComparable(t, new(float64))
 	testWriteComparable(t, float64(9))
 	testWriteComparable(t, complex128(9i+1))
+	testWriteComparable(t, struct{}{})
 	testWriteComparable(t, struct {
 		i int
+		u uint
+		b bool
 		f float64
-	}{i: 9, f: 9.9})
+		p *int
+		a any
+	}{i: 9, u: 1, b: true, f: 9.9, p: new(int), a: 1})
 	type S struct {
 		s string
 	}
@@ -326,17 +352,28 @@ func TestWriteComparable(t *testing.T) {
 		t.Fatalf("unexpected two heapStr value not equal")
 	}
 	testWriteComparable(t, s1, s2)
+	testWriteComparable(t, s1.s, s2.s)
 	testWriteComparable(t, float32(0), negativeZero[float32]())
 	testWriteComparable(t, float64(0), negativeZero[float64]())
+	testWriteComparableNoEqual(t, math.NaN(), math.NaN())
+	testWriteComparableNoEqual(t, [2]string{"a", ""}, [2]string{"", "a"})
+	testWriteComparableNoEqual(t, any(struct{ x int }{x: 1}), any(struct {
+		x int
+		s string
+	}{x: 1}))
+}
+
+func testWriteComparableNoEqual[T comparable](t *testing.T, v1, v2 T) {
 	seed := MakeSeed()
 	h1 := Hash{}
 	h2 := Hash{}
 	h1.seed, h2.seed = seed, seed
-	WriteComparable(&h1, math.NaN())
-	WriteComparable(&h2, math.NaN())
+	WriteComparable(&h1, v1)
+	WriteComparable(&h2, v2)
 	if h1.Sum64() == h2.Sum64() {
-		t.Fatalf("WriteComparable(seed, NaN) == WriteComparable(seed, NaN)")
+		t.Fatalf("WriteComparable(seed, %v) == WriteComparable(seed, %v)", v1, v2)
 	}
+
 }
 
 func testWriteComparable[T comparable](t *testing.T, v T, v2 ...T) {