/*************************************************************************
 * Copyright (c) 2016-2022, NVIDIA CORPORATION. All rights reserved.
 * Modifications Copyright (c) 2019-2022 Advanced Micro Devices, Inc. All rights reserved.
 *
 * See LICENSE.txt for license information
 ************************************************************************/

#include "cuda_runtime.h"
#include "common.h"

#define ALIGN 4

void ReduceScatterGetCollByteCount(size_t *sendcount, size_t *recvcount, size_t *paramcount, size_t *sendInplaceOffset, size_t *recvInplaceOffset, size_t count, int nranks) {
  size_t base = (count/(ALIGN*nranks))*ALIGN;
  *sendcount = base*nranks;
  *recvcount = base;
  *sendInplaceOffset = 0;
  *recvInplaceOffset = base;
  *paramcount = base;
}

testResult_t ReduceScatterInitData(struct threadArgs* args, ncclDataType_t type, ncclRedOp_t op, int root, int rep, int in_place) {
  size_t sendcount = args->sendBytes / wordSize(type);
  size_t recvcount = args->expectedBytes / wordSize(type);
  int nranks = args->nProcs*args->nThreads*args->nGpus;

  for (int i=0; i<args->nGpus; i++) {
    CUDACHECK(cudaSetDevice(args->gpus[i]));
    int rank = ((args->proc*args->nThreads + args->thread)*args->nGpus + i);
    CUDACHECK(cudaMemset(args->recvbuffs[i], 0, args->expectedBytes));
    void* data = in_place ? args->recvbuffs[i] : args->sendbuffs[i];
    TESTCHECK(InitData(data, sendcount, 0, type, op, rep, nranks, rank));
    CUDACHECK(cudaMemcpy(args->expected[i], args->recvbuffs[i], args->expectedBytes, cudaMemcpyDefault));
    TESTCHECK(InitDataReduce(args->expected[i], recvcount, rank*recvcount, type, op, rep, nranks));
    CUDACHECK(cudaDeviceSynchronize());
  }
  return testSuccess;
}

void ReduceScatterGetBw(size_t count, int typesize, double sec, double* algBw, double* busBw, int nranks) {
  double baseBw = (double)(count * typesize * nranks) / 1.0E9 / sec;

  *algBw = baseBw;
  double factor = ((double)(nranks - 1))/((double)nranks);
  *busBw = baseBw * factor;
}

testResult_t ReduceScatterRunColl(void* sendbuff, void* recvbuff, size_t count, ncclDataType_t type, ncclRedOp_t op, int root, ncclComm_t comm, cudaStream_t stream) {
  NCCLCHECK(ncclReduceScatter(sendbuff, recvbuff, count, type, op, comm, stream));
  return testSuccess;
}

struct testColl reduceScatterTest = {
  "ReduceScatter",
  ReduceScatterGetCollByteCount,
  ReduceScatterInitData,
  ReduceScatterGetBw,
  ReduceScatterRunColl
};

void ReduceScatterGetBuffSize(size_t *sendcount, size_t *recvcount, size_t count, int nranks) {
  size_t paramcount, sendInplaceOffset, recvInplaceOffset;
  ReduceScatterGetCollByteCount(sendcount, recvcount, &paramcount, &sendInplaceOffset, &recvInplaceOffset, count, nranks);
}

testResult_t ReduceScatterRunTest(struct threadArgs* args, int root, ncclDataType_t type, const char* typeName, ncclRedOp_t op, const char* opName) {
  args->collTest = &reduceScatterTest;
  ncclDataType_t *run_types;
  ncclRedOp_t *run_ops;
  const char **run_typenames, **run_opnames;
  int type_count, op_count;

  if ((int)type != -1) {
    type_count = 1;
    run_types = &type;
    run_typenames = &typeName;
  } else {
    type_count = test_typenum;
    run_types = test_types;
    run_typenames = test_typenames;
  }

  if ((int)op != -1) {
    run_ops = &op;
    run_opnames = &opName;
    op_count = 1;
  } else {
    op_count = test_opnum;
    run_ops = test_ops;
    run_opnames = test_opnames;
  }

  for (int i=0; i<type_count; i++) {
    for (int j=0; j<op_count; j++) {
#if defined(RCCL_FLOAT8)
      if((run_types[i] == ncclFp8E4M3 || run_types[i] == ncclFp8E5M2) && run_ops[j] == ncclProd)
        continue;
#endif
      TESTCHECK(TimeTest(args, run_types[i], run_typenames[i], run_ops[j], run_opnames[j], -1));
    }
  }
  return testSuccess;
}

struct testEngine ncclTestEngine = {
  ReduceScatterGetBuffSize,
  ReduceScatterRunTest
};
