eth: opt incHash

[cuiweixie]

test and bench:

package main import (	"bytes"	"testing"	"github.com/ethereum/go-ethereum/common"	"github.com/holiman/uint256" ) func incHash(h common.Hash) common.Hash {	var a uint256.Int	a.SetBytes32(h[:])	a.AddUint64(&a, 1)	return common.Hash(a.Bytes32()) } func incHashFast(h common.Hash) common.Hash {	for i := len(h) - 1; i >= 0; i-- {	h[i]++	if h[i] != 0 {	break	}	}	return h } func TestIncHashCorrectness(t *testing.T) {	testCases := []common.Hash{	common.HexToHash("0x0"),	common.HexToHash("0x01"),	common.HexToHash("0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"), // 最大值	common.HexToHash("0x00000000000000000000000000000000000000000000000000000000ffffffff"), // 边界	}	for _, tc := range testCases {	got1 := incHash(tc)	got2 := incHashFast(tc)	if !bytes.Equal(got1[:], got2[:]) {	t.Errorf("Mismatch for %x: uint256=%x fast=%x", tc, got1, got2)	}	} } // Benchmark origin func BenchmarkIncHash(b *testing.B) {	var h common.Hash	for i := 0; i < b.N; i++ {	_ = incHash(h)	} } // Benchmark optimized func BenchmarkIncHashFast(b *testing.B) {	var h common.Hash	for i := 0; i < b.N; i++ {	_ = incHashFast(h)	} } 

goos: darwin goarch: arm64 pkg: github.com/cuiweixie/mylabs/tests/inc_hash cpu: Apple M1 Pro BenchmarkIncHash BenchmarkIncHash-10	175488444 6.941 ns/op BenchmarkIncHashFast BenchmarkIncHashFast-10	1000000000 0.8142 ns/op PASS