ssz HashTreeRoot is different in window 386 environment

[fearlessfe]

In window 386 environment, the result of HashTreeRoot is different with amd64(both window or linux)

the sample code and the data file is below.

when build CGO_ENABLED=0 GOOS=windows GOARCH=386 go build main.go, the epochRoot is different epoch.txt

package main

import (
    "encoding/hex"
    "fmt"

    ssz "github.com/ferranbt/fastssz"
)

//go:embed epoch.txt
var epochAccuHex string

func main() {
    epochAccuBytes, err := hex.DecodeString(epochAccuHex)
    if err != nil {
        panic(err)
    }
    epochAccu, err := DecodeEpochAccumulator(epochAccuBytes)
    if err != nil {
        panic(err)
    }
    epochRoot, err := epochAccu.HashTreeRoot()
    if err != nil {
        panic(err)
    }
        // differ in window 386
    fmt.Println("epochRoot:" + hex.EncodeToString(epochRoot[:]))
}

func DecodeEpochAccumulator(data []byte) (*EpochAccumulator, error) {
    epochAccu := new(EpochAccumulator)
    err := epochAccu.UnmarshalSSZ(data)
    return epochAccu, err
}

type EpochAccumulator struct {
    HeaderRecords [][]byte `ssz-size:"8192,64"`
}

// MarshalSSZ ssz marshals the EpochAccumulator object
func (e *EpochAccumulator) MarshalSSZ() ([]byte, error) {
    return ssz.MarshalSSZ(e)
}

// MarshalSSZTo ssz marshals the EpochAccumulator object to a target array
func (e *EpochAccumulator) MarshalSSZTo(buf []byte) (dst []byte, err error) {
    dst = buf

    // Field (0) 'HeaderRecords'
    if size := len(e.HeaderRecords); size != 8192 {
        err = ssz.ErrVectorLengthFn("EpochAccumulator.HeaderRecords", size, 8192)
        return
    }
    for ii := 0; ii < 8192; ii++ {
        if size := len(e.HeaderRecords[ii]); size != 64 {
            err = ssz.ErrBytesLengthFn("EpochAccumulator.HeaderRecords[ii]", size, 64)
            return
        }
        dst = append(dst, e.HeaderRecords[ii]...)
    }

    return
}

// UnmarshalSSZ ssz unmarshals the EpochAccumulator object
func (e *EpochAccumulator) UnmarshalSSZ(buf []byte) error {
    var err error
    size := uint64(len(buf))
    if size != 524288 {
        return ssz.ErrSize
    }

    // Field (0) 'HeaderRecords'
    e.HeaderRecords = make([][]byte, 8192)
    for ii := 0; ii < 8192; ii++ {
        if cap(e.HeaderRecords[ii]) == 0 {
            e.HeaderRecords[ii] = make([]byte, 0, len(buf[0:524288][ii*64:(ii+1)*64]))
        }
        e.HeaderRecords[ii] = append(e.HeaderRecords[ii], buf[0:524288][ii*64:(ii+1)*64]...)
    }

    return err
}

// SizeSSZ returns the ssz encoded size in bytes for the EpochAccumulator object
func (e *EpochAccumulator) SizeSSZ() (size int) {
    size = 524288
    return
}

// HashTreeRoot ssz hashes the EpochAccumulator object
func (e *EpochAccumulator) HashTreeRoot() ([32]byte, error) {
    return ssz.HashWithDefaultHasher(e)
}

// HashTreeRootWith ssz hashes the EpochAccumulator object with a hasher
func (e *EpochAccumulator) HashTreeRootWith(hh ssz.HashWalker) (err error) {
    indx := hh.Index()

    // Field (0) 'HeaderRecords'
    {
        if size := len(e.HeaderRecords); size != 8192 {
            err = ssz.ErrVectorLengthFn("EpochAccumulator.HeaderRecords", size, 8192)
            return
        }
        subIndx := hh.Index()
        for _, i := range e.HeaderRecords {
            if len(i) != 64 {
                err = ssz.ErrBytesLength
                return
            }
            hh.PutBytes(i)
        }
        hh.Merkleize(subIndx)
    }

    hh.Merkleize(indx)
    return
}

// GetTree ssz hashes the EpochAccumulator object
func (e *EpochAccumulator) GetTree() (*ssz.Node, error) {
    return ssz.ProofTree(e)
}

[ferranbt]

Hello. I do not have a windows machine to test this on my side. Is there any way you could give me more info on the issue? Is it a matter of the hash protocol or byte manipulation of the hasher library? You could print the values at this line, it is where the core part of the hashing happens.

[fearlessfe]

I print the input

the output is quite different, here is the result of linux amd64

next is the output of window 386

[GrapeBaBa]

@ferranbt Any suggestion for further investigation?

[ferranbt]

It is not easy to figure out what is wrong with only that output. Please try to reproduce the issue with an example with less data (i.e. accumulator array with a couple of entries only).

[GrapeBaBa]

It is not easy to figure out what is wrong with only that output. Please try to reproduce the issue with an example with less data (i.e. accumulator array with a couple of entries only).

@fearlessfe can you help?

[ferranbt]

Closing due to inactivity.