MoE Dispatch/Combine first implementation for k=1 and Nccl backend

CMakeLists.txt

@@ -235,6 +235,7 @@ list(APPEND NVFUSER_SRCS
   ${NVFUSER_SRCS_DIR}/multidevice/communication.cpp
   ${NVFUSER_SRCS_DIR}/multidevice/communicator.cpp
   ${NVFUSER_SRCS_DIR}/multidevice/cuda_p2p.cpp
+  ${NVFUSER_SRCS_DIR}/multidevice/dispatch_combine.cpp
   ${NVFUSER_SRCS_DIR}/multidevice/ipc_handle.cpp
   ${NVFUSER_SRCS_DIR}/multidevice/ipc_utils.cpp
   ${NVFUSER_SRCS_DIR}/multidevice/device_mesh.cpp
@@ -1143,6 +1144,7 @@ if(BUILD_TEST)
     ${NVFUSER_ROOT}/tests/cpp/multidevice.cpp
     ${NVFUSER_ROOT}/tests/cpp/multidevice_transformer.cpp
     ${NVFUSER_ROOT}/tests/cpp/test_multidevice_communications.cpp
+    ${NVFUSER_ROOT}/tests/cpp/test_multidevice_dispatch_combine.cpp
     ${NVFUSER_ROOT}/tests/cpp/test_multidevice_communicator.cpp
     ${NVFUSER_ROOT}/tests/cpp/test_multidevice_host_ir.cpp
     ${NVFUSER_ROOT}/tests/cpp/test_multidevice_host_ir_overlap.cpp

csrc/dispatch.h

@@ -118,6 +118,8 @@ class Val;
   f(Merge);                          \
   f(Partition);                      \
   f(Combine);                        \
+  f(MoeDispatch);                    \
+  f(MoeCombine);                     \
   f(Swizzle);                        \
   f(Resize);                         \
   f(MatmulOp);                       \

csrc/host_ir/evaluator.cpp

@@ -25,6 +25,7 @@
 #include "multidevice/allocation_utils.h"
 #include "multidevice/communication.h"
 #include "multidevice/cuda_p2p.h"
+#include "multidevice/dispatch_combine.h"
 #include "multidevice/execution_utils.h"
 #include "multidevice/symmetric_tensor.h"
 #include "multidevice/utils.h"
@@ -386,6 +387,58 @@ void HostIrEvaluator::handle(P2PCommunication* communication) {
   }
 }
 
+void HostIrEvaluator::handle(MoeDispatch* dispatch) {
+  NVF_ERROR(
+      communicator_ != nullptr && communicator_->is_available(),
+      "A valid communicator must be provided");
+
+  auto x = getKnownConcreteValue(dispatch->inX()).as<at::Tensor>();
+  auto topk_idx = getKnownConcreteValue(dispatch->inTopkIdx()).as<at::Tensor>();
+  auto is_token_in_rank =
+      getKnownConcreteValue(dispatch->inIsTokenInRank()).as<at::Tensor>();
+
+  auto result = doMoeDispatch(
+      x,
+      topk_idx,
+      is_token_in_rank,
+      dispatch->numExperts(),
+      communicator_,
+      dispatch->backend());
+
+  expr_evaluator_.bind(dispatch->outX(), result.recv_x);
+  expr_evaluator_.bind(dispatch->outTopkIdx(), result.recv_topk_idx);
+  expr_evaluator_.bind(dispatch->outSrcIdx(), result.recv_src_idx);
+  expr_evaluator_.bind(dispatch->outSrcRank(), result.recv_src_rank);
+  expr_evaluator_.bind(dispatch->outTokensToRank(), result.n_tokens_to_rank);
+  expr_evaluator_.bind(
+      dispatch->outTokensFromRank(), result.n_tokens_from_rank);
+}
+
+void HostIrEvaluator::handle(MoeCombine* combine) {
+  NVF_ERROR(
+      communicator_ != nullptr && communicator_->is_available(),
+      "A valid communicator must be provided");
+
+  auto x = getKnownConcreteValue(combine->inX()).as<at::Tensor>();
+  auto src_idx = getKnownConcreteValue(combine->inSrcIdx()).as<at::Tensor>();
+  auto src_rank = getKnownConcreteValue(combine->inSrcRank()).as<at::Tensor>();
+  auto n_tokens_to_rank =
+      getKnownConcreteValue(combine->inTokensToRank()).as<at::Tensor>();
+  auto n_tokens_from_rank =
+      getKnownConcreteValue(combine->inTokensFromRank()).as<at::Tensor>();
+
+  auto result = doMoeCombine(
+      x,
+      src_idx,
+      src_rank,
+      n_tokens_to_rank,
+      n_tokens_from_rank,
+      communicator_,
+      combine->backend());
+
+  expr_evaluator_.bind(combine->outX(), result.combined_x);
+}
+
 void HostIrEvaluator::handle(Wait* wait) {
   Expr* expr = wait->communication();
   auto* p2p_comm = dynamic_cast<P2PCommunication*>(expr);

csrc/host_ir/evaluator.h

@@ -98,6 +98,8 @@ class NVF_API HostIrEvaluator final : public OptOutDispatch {
   void handle(LaunchKernel*) override;
   void handle(Communication*) override;
   void handle(P2PCommunication*) override;
+  void handle(MoeDispatch*) override;
+  void handle(MoeCombine*) override;
   void handle(Wait*) override;
   void handle(kir::ForLoop*) override;
   void handle(hir::ForLoop*) override;

csrc/multidevice/communication.cpp

@@ -321,6 +321,143 @@ std::string P2PCommunication::toString(int indent_size) const {
   return toInlineString(indent_size) + "\n";
 }
 
+MoeDispatch::MoeDispatch(
+    IrBuilderPasskey passkey,
+    TensorView* out_x,
+    TensorView* out_topk_idx,
+    TensorView* out_src_idx,
+    TensorView* out_src_rank,
+    TensorView* out_n_tokens_to_rank,
+    TensorView* out_n_tokens_from_rank,
+    TensorView* in_x,
+    TensorView* in_topk_idx,
+    TensorView* in_is_token_in_rank,
+    int64_t num_experts,
+    CommunicatorBackend backend)
+    : Expr(passkey) {
+  addInput(in_x);
+  addInput(in_topk_idx);
+  addInput(in_is_token_in_rank);
+  addOutput(out_x);
+  addOutput(out_topk_idx);
+  addOutput(out_src_idx);
+  addOutput(out_src_rank);
+  addOutput(out_n_tokens_to_rank);
+  addOutput(out_n_tokens_from_rank);
+  addDataAttribute(num_experts);
+  addDataAttribute(backend);
+  validate();
+}
+
+NVFUSER_DEFINE_CLONE_AND_CREATE(MoeDispatch)
+
+std::string MoeDispatch::toInlineString(int indent_size) const {
+  std::stringstream ss;
+  indent(ss, indent_size) << "Dispatch " << name() << " ("
+                          << "num_experts=" << numExperts() << ", "
+                          << "backend=" << backend() << ", "
+                          << "in=" << inX() << ", "
+                          << "topk_idx=" << inTopkIdx() << ", "
+                          << "is_token_in_rank=" << inIsTokenInRank() << ", "
+                          << "out=" << outX() << ")";
+  return ss.str();
+}
+
+std::string MoeDispatch::toString(int indent_size) const {
+  return toInlineString(indent_size) + "\n";
+}
+
+void MoeDispatch::validate() {
+  NVF_CHECK(numExperts() > 0, "num_experts must be positive.");
+  NVF_CHECK(inX()->isA<TensorView>(), "in_x must be a TensorView.");
+  NVF_CHECK(inTopkIdx()->isA<TensorView>(), "topk_idx must be a TensorView.");
+  NVF_CHECK(
+      inTopkIdx()->getDataType().has_value() &&
+          isIntegralType(*inTopkIdx()->getDataType()),
+      "topk_idx must be integral.");
+  NVF_CHECK(
+      inIsTokenInRank()->getDataType().has_value() &&
+          inIsTokenInRank()->getDataType() == DataType::Bool,
+      "is_token_in_rank must be Bool.");
+  NVF_CHECK(
+      outTopkIdx()->getDataType().has_value() &&
+          isIntegralType(*outTopkIdx()->getDataType()),
+      "out_topk_idx must be integral.");
+  NVF_CHECK(
+      outSrcIdx()->getDataType().has_value() &&
+          isIntegralType(*outSrcIdx()->getDataType()),
+      "out_src_idx must be integral.");
+  NVF_CHECK(
+      outSrcRank()->getDataType().has_value() &&
+          isIntegralType(*outSrcRank()->getDataType()),
+      "out_src_rank must be integral.");
+  NVF_CHECK(
+      outTokensToRank()->getDataType().has_value() &&
+          isIntegralType(*outTokensToRank()->getDataType()),
+      "out_n_tokens_to_rank must be integral.");
+  NVF_CHECK(
+      outTokensFromRank()->getDataType().has_value() &&
+          isIntegralType(*outTokensFromRank()->getDataType()),
+      "out_n_tokens_from_rank must be integral.");
+}
+
+MoeCombine::MoeCombine(
+    IrBuilderPasskey passkey,
+    TensorView* out_x,
+    TensorView* in_x,
+    TensorView* in_src_idx,
+    TensorView* in_src_rank,
+    TensorView* in_n_tokens_to_rank,
+    TensorView* in_n_tokens_from_rank,
+    CommunicatorBackend backend)
+    : Expr(passkey) {
+  addInput(in_x);
+  addInput(in_src_idx);
+  addInput(in_src_rank);
+  addInput(in_n_tokens_to_rank);
+  addInput(in_n_tokens_from_rank);
+  addOutput(out_x);
+  addDataAttribute(backend);
+  validate();
+}
+
+NVFUSER_DEFINE_CLONE_AND_CREATE(MoeCombine)
+
+std::string MoeCombine::toInlineString(int indent_size) const {
+  std::stringstream ss;
+  indent(ss, indent_size) << "Combine " << name() << " ("
+                          << "backend=" << backend() << ", "
+                          << "in=" << inX() << ", "
+                          << "src_idx=" << inSrcIdx() << ", "
+                          << "src_rank=" << inSrcRank() << ", "
+                          << "out=" << outX() << ")";
+  return ss.str();
+}
+
+std::string MoeCombine::toString(int indent_size) const {
+  return toInlineString(indent_size) + "\n";
+}
+
+void MoeCombine::validate() {
+  NVF_CHECK(inX()->isA<TensorView>(), "in_x must be a TensorView.");
+  NVF_CHECK(
+      inSrcIdx()->getDataType().has_value() &&
+          isIntegralType(*inSrcIdx()->getDataType()),
+      "in_src_idx must be integral.");
+  NVF_CHECK(
+      inSrcRank()->getDataType().has_value() &&
+          isIntegralType(*inSrcRank()->getDataType()),
+      "in_src_rank must be integral.");
+  NVF_CHECK(
+      inTokensToRank()->getDataType().has_value() &&
+          isIntegralType(*inTokensToRank()->getDataType()),
+      "in_n_tokens_to_rank must be integral.");
+  NVF_CHECK(
+      inTokensFromRank()->getDataType().has_value() &&
+          isIntegralType(*inTokensFromRank()->getDataType()),
+      "in_n_tokens_from_rank must be integral.");
+}
+
 namespace {
 c10::intrusive_ptr<c10d::Work> postBroadcast(
     Communication* communication,