Update to go1.24.0

src/internal/fuzz/mutators_byteslice_test.go

@@ -6,6 +6,7 @@ package fuzz
 
 import (
 	"bytes"
+	"fmt"
 	"testing"
 )
 
@@ -33,12 +34,6 @@ func (mr *mockRand) uint32n(n uint32) uint32 {
 	return uint32(c) % n
 }
 
-func (mr *mockRand) exp2() int {
-	c := mr.values[mr.counter]
-	mr.counter++
-	return c
-}
-
 func (mr *mockRand) bool() bool {
 	b := mr.b
 	mr.b = !mr.b
@@ -184,3 +179,43 @@ func TestByteSliceMutators(t *testing.T) {
 		})
 	}
 }
+
+func BenchmarkByteSliceMutators(b *testing.B) {
+	tests := [...]struct {
+		name    string
+		mutator func(*mutator, []byte) []byte
+	}{
+		{"RemoveBytes", byteSliceRemoveBytes},
+		{"InsertRandomBytes", byteSliceInsertRandomBytes},
+		{"DuplicateBytes", byteSliceDuplicateBytes},
+		{"OverwriteBytes", byteSliceOverwriteBytes},
+		{"BitFlip", byteSliceBitFlip},
+		{"XORByte", byteSliceXORByte},
+		{"SwapByte", byteSliceSwapByte},
+		{"ArithmeticUint8", byteSliceArithmeticUint8},
+		{"ArithmeticUint16", byteSliceArithmeticUint16},
+		{"ArithmeticUint32", byteSliceArithmeticUint32},
+		{"ArithmeticUint64", byteSliceArithmeticUint64},
+		{"OverwriteInterestingUint8", byteSliceOverwriteInterestingUint8},
+		{"OverwriteInterestingUint16", byteSliceOverwriteInterestingUint16},
+		{"OverwriteInterestingUint32", byteSliceOverwriteInterestingUint32},
+		{"InsertConstantBytes", byteSliceInsertConstantBytes},
+		{"OverwriteConstantBytes", byteSliceOverwriteConstantBytes},
+		{"ShuffleBytes", byteSliceShuffleBytes},
+		{"SwapBytes", byteSliceSwapBytes},
+	}
+
+	for _, tc := range tests {
+		b.Run(tc.name, func(b *testing.B) {
+			for size := 64; size <= 1024; size *= 2 {
+				b.Run(fmt.Sprintf("%d", size), func(b *testing.B) {
+					m := &mutator{r: newPcgRand()}
+					input := make([]byte, size)
+					for i := 0; i < b.N; i++ {
+						tc.mutator(m, input)
+					}
+				})
+			}
+		})
+	}
+}

src/internal/fuzz/pcg.go

@@ -17,7 +17,6 @@ type mutatorRand interface {
 	uint32() uint32
 	intn(int) int
 	uint32n(uint32) uint32
-	exp2() int
 	bool() bool
 
 	save(randState, randInc *uint64)
@@ -123,11 +122,6 @@ func (r *pcgRand) uint32n(n uint32) uint32 {
 	return uint32(prod >> 32)
 }
 
-// exp2 generates n with probability 1/2^(n+1).
-func (r *pcgRand) exp2() int {
-	return bits.TrailingZeros32(r.uint32())
-}
-
 // bool generates a random bool.
 func (r *pcgRand) bool() bool {
 	return r.uint32()&1 == 0

src/internal/fuzz/worker.go

@@ -682,7 +682,7 @@ func (ws *workerServer) serve(ctx context.Context) error {
 }
 
 // chainedMutations is how many mutations are applied before the worker
-// resets the input to it's original state.
+// resets the input to its original state.
 // NOTE: this number was picked without much thought. It is low enough that
 // it seems to create a significant diversity in mutated inputs. We may want
 // to consider looking into this more closely once we have a proper performance