[AMD] Introduce an OptimizeLDSUsage pass

bin/RegisterTritonDialects.h

@@ -52,6 +52,7 @@ inline void registerTritonDialects(mlir::DialectRegistry &registry) {
   mlir::triton::registerConvertTritonAMDGPUToLLVM();
   mlir::triton::registerConvertBuiltinFuncToLLVM();
   mlir::triton::registerDecomposeUnsupportedAMDConversions();
+  mlir::triton::registerOptimizeAMDLDSUsage();
 
   // TritonAMDGPUTransforms passes
   mlir::registerTritonAMDGPUAccelerateMatmul();

include/triton/Analysis/Allocation.h

@@ -21,7 +21,13 @@ class AllocationAnalysis;
 SmallVector<unsigned>
 getScratchConfigForCvtLayout(triton::gpu::ConvertLayoutOp op, unsigned &inVec,
                              unsigned &outVec);
+SmallVector<unsigned> getScratchConfigForCvtLayout(RankedTensorType srcType,
+                                                   RankedTensorType dstType,
+                                                   unsigned &inVec,
+                                                   unsigned &outVec);
 SmallVector<unsigned> getRepShapeForCvtLayout(triton::gpu::ConvertLayoutOp op);
+SmallVector<unsigned> getRepShapeForCvtLayout(RankedTensorType srcTy,
+                                              RankedTensorType dstTy);
 
 } // namespace triton
 
@@ -135,6 +141,9 @@ class Allocation {
   /// Returns the size of total shared memory allocated
   size_t getSharedMemorySize() const { return sharedMemorySize; }
 
+  /// Returns mapping from operation to list of live LDS buffers
+  std::map<Operation *, SmallVector<BufferId>> getLiveBuffers();
+
 private:
   /// A class that represents a shared memory buffer
   struct BufferT {

lib/Analysis/Allocation.cpp

@@ -60,6 +60,11 @@ getCvtOrder(Attribute srcLayout, Attribute dstLayout) {
 SmallVector<unsigned> getRepShapeForCvtLayout(triton::gpu::ConvertLayoutOp op) {
   auto srcTy = op.getSrc().getType();
   auto dstTy = op.getType();
+  return getRepShapeForCvtLayout(srcTy, dstTy);
+}
+
+SmallVector<unsigned> getRepShapeForCvtLayout(RankedTensorType srcTy,
+                                              RankedTensorType dstTy) {
   Attribute srcLayout = srcTy.getEncoding();
   Attribute dstLayout = dstTy.getEncoding();
 
@@ -92,12 +97,19 @@ SmallVector<unsigned> getRepShapeForCvtLayout(triton::gpu::ConvertLayoutOp op) {
 SmallVector<unsigned>
 getScratchConfigForCvtLayout(triton::gpu::ConvertLayoutOp op, unsigned &inVec,
                              unsigned &outVec) {
-  auto repShape = getRepShapeForCvtLayout(op);
+  auto srcTy = op.getSrc().getType();
+  auto dstTy = op.getType();
+  return getScratchConfigForCvtLayout(srcTy, dstTy, inVec, outVec);
+}
+
+SmallVector<unsigned> getScratchConfigForCvtLayout(RankedTensorType srcTy,
+                                                   RankedTensorType dstTy,
+                                                   unsigned &inVec,
+                                                   unsigned &outVec) {
+  auto repShape = getRepShapeForCvtLayout(srcTy, dstTy);
   if (repShape.empty())
     return repShape;
   auto rank = repShape.size();
-  auto srcTy = op.getSrc().getType();
-  auto dstTy = op.getType();
   Attribute srcLayout = srcTy.getEncoding();
   Attribute dstLayout = dstTy.getEncoding();
 
@@ -627,4 +639,27 @@ void Allocation::run(FuncAllocMapT &funcAllocMap) {
   triton::AllocationAnalysis(getOperation(), &funcAllocMap, this);
 }
 
+std::map<Operation *, SmallVector<Allocation::BufferId>>
+Allocation::getLiveBuffers() {
+  std::map<Operation *, SmallVector<BufferId>> liveBuffers;
+
+  Operation *rootOperation = getOperation();
+  mlir::Liveness liveness(rootOperation);
+  auto analyzeOperation = [&](Operation *op) -> void {
+    auto scratchBuffer = getBufferId(op);
+    if (scratchBuffer != InvalidBufferId)
+      liveBuffers[op].push_back(scratchBuffer);
+    for (auto result : op->getOpResults()) {
+      auto bufferId = getBufferId(result);
+      if (bufferId == Allocation::InvalidBufferId)
+        continue;
+      auto liveOperations = liveness.resolveLiveness(result);
+      for (auto depOp : liveOperations)
+        liveBuffers[depOp].push_back(bufferId);
+    }
+  };
+  rootOperation->walk(analyzeOperation);
+  return liveBuffers;
+}
+
 } // namespace mlir

test/TritonGPU/amd/optimize-lds-usage.mlir

@@ -0,0 +1,89 @@
+// RUN: triton-opt %s -split-input-file -optimize-amd-lds-usage=target-arch=gfx90a | FileCheck %s
+// RUN: triton-opt %s -split-input-file -optimize-amd-lds-usage=target-arch=gfx90a -optimize-amd-lds-usage=lds-limit=32768 | FileCheck %s --check-prefix=CHECK-32KLIMIT
+
+// Check that optimization detects overflow of LDS and decomposes layout convert so kernel fits into LDS
+// CHECK-LABEL: alloc_convert_load
+// CHECK-32KLIMIT-LABEL: alloc_convert_load
+// CHECK: %0 = triton_gpu.local_alloc %arg0 : {{.*}}#blocked{{.*}}#shared
+// CHECK: %1 = triton_gpu.convert_layout %arg1 : {{.*}}#blocked{{.*}}#blocked1
+// CHECK: %2 = triton_gpu.convert_layout %1 : {{.*}}#blocked1{{.*}}#mma
+// CHECK: %3 = triton_gpu.local_load %0 : {{.*}}#shared{{.*}}#triton_gpu.dot_op<{opIdx = 0, parent = #mma, kWidth = 4}>>
+#blocked = #triton_gpu.blocked<{sizePerThread = [8, 1], threadsPerWarp = [16, 4], warpsPerCTA = [1, 8], order = [0, 1]}>
+#mma = #triton_gpu.amd_mfma<{versionMajor = 2, versionMinor = 0, warpsPerCTA = [1, 8], instrShape = [32, 32], isTransposed = false}>
+#shared = #triton_gpu.shared<{vec = 4, perPhase = 1, maxPhase = 16, order = [0, 1], hasLeadingOffset = false}>
+module attributes {"triton_gpu.num-warps" = 8 : i32, "triton_gpu.threads-per-warp" = 64 : i32} {
+  tt.func public @alloc_convert_load(%arg0: tensor<128x128xf16, #blocked>, %arg1: tensor<128x128xf32, #blocked>) attributes {noinline = false} {
+    %1 = triton_gpu.local_alloc %arg0 : (tensor<128x128xf16, #blocked>) -> !tt.memdesc<128x128xf16, #shared, #triton_gpu.shared_memory>
+    %2 = triton_gpu.convert_layout %arg1 : tensor<128x128xf32, #blocked> -> tensor<128x128xf32, #mma>
+    %3 = triton_gpu.local_load %1 : !tt.memdesc<128x128xf16, #shared, #triton_gpu.shared_memory> -> tensor<128x128xf16, #triton_gpu.dot_op<{opIdx = 0, parent = #mma, kWidth = 4}>>
+    tt.return
+  }
+}
+
+// -----
+
+// Check that optimization detects overflow of LDS and decomposes layout convert so kernel fits into LDS
+// in case of relatively small scratch buffer
+// CHECK-LABEL: alloc_convert_small_load
+// CHECK-32KLIMIT-LABEL: alloc_convert_small_load
+// CHECK: %0 = triton_gpu.local_alloc %arg0 : {{.*}}#blocked{{.*}}#shared
+// CHECK: %1 = triton_gpu.convert_layout %arg1 : {{.*}}#blocked{{.*}}#blocked1
+// CHECK: %2 = triton_gpu.convert_layout %1 : {{.*}}#blocked1{{.*}}#mma
+// CHECK: %3 = triton_gpu.local_load %0 : {{.*}}#shared{{.*}}#triton_gpu.dot_op<{opIdx = 0, parent = #mma, kWidth = 4}>>
+#blocked = #triton_gpu.blocked<{sizePerThread = [8, 1], threadsPerWarp = [16, 4], warpsPerCTA = [1, 8], order = [0, 1]}>
+#mma = #triton_gpu.amd_mfma<{versionMajor = 2, versionMinor = 0, warpsPerCTA = [1, 8], instrShape = [32, 32], isTransposed = false}>
+#shared = #triton_gpu.shared<{vec = 4, perPhase = 1, maxPhase = 16, order = [0, 1], hasLeadingOffset = false}>
+module attributes {"triton_gpu.num-warps" = 8 : i32, "triton_gpu.threads-per-warp" = 64 : i32} {
+  tt.func public @alloc_convert_small_load(%arg0: tensor<128x128xf16, #blocked>, %arg1: tensor<128x128xf16, #blocked>) attributes {noinline = false} {
+    %1 = triton_gpu.local_alloc %arg0 : (tensor<128x128xf16, #blocked>) -> !tt.memdesc<128x128xf16, #shared, #triton_gpu.shared_memory>
+    %2 = triton_gpu.convert_layout %arg1 : tensor<128x128xf16, #blocked> -> tensor<128x128xf16, #mma>
+    %3 = triton_gpu.local_load %1 : !tt.memdesc<128x128xf16, #shared, #triton_gpu.shared_memory> -> tensor<128x128xf16, #triton_gpu.dot_op<{opIdx = 0, parent = #mma, kWidth = 4}>>
+    tt.return
+  }
+}
+
+// -----
+
+// Check that optimization works with 3d tensors
+// in case of relatively small scratch buffer
+// CHECK-LABEL: alloc_convert_3d_load
+// CHECK-32KLIMIT-LABEL: alloc_convert_3d_load
+// CHECK: %0 = triton_gpu.local_alloc %arg0 : {{.*}}#blocked{{.*}}#shared
+// CHECK: %1 = triton_gpu.convert_layout %arg1 : {{.*}}#blocked{{.*}}#mma
+// CHECK: %2 = triton_gpu.convert_layout %1 : {{.*}}#mma{{.*}}#mma1
+// CHECK: %3 = triton_gpu.local_load %0 : {{.*}}#shared{{.*}}#triton_gpu.dot_op<{opIdx = 0, parent = #mma1, kWidth = 4}>>
+#blocked = #triton_gpu.blocked<{sizePerThread = [1, 8, 1], threadsPerWarp = [1, 16, 4], warpsPerCTA = [1, 1, 8], order = [0, 1, 2]}>
+#mma = #triton_gpu.amd_mfma<{versionMajor = 2, versionMinor = 0, warpsPerCTA = [1, 1, 8], instrShape = [32, 32], isTransposed = false}>
+#shared = #triton_gpu.shared<{vec = 4, perPhase = 1, maxPhase = 16, order = [0, 1, 2], hasLeadingOffset = false}>
+module attributes {"triton_gpu.num-warps" = 8 : i32, "triton_gpu.threads-per-warp" = 64 : i32} {
+  tt.func public @alloc_convert_3d_load(%arg0: tensor<1x128x128xf16, #blocked>, %arg1: tensor<1x128x128xf16, #blocked>) attributes {noinline = false} {
+    %1 = triton_gpu.local_alloc %arg0 : (tensor<1x128x128xf16, #blocked>) -> !tt.memdesc<1x128x128xf16, #shared, #triton_gpu.shared_memory>
+    %2 = triton_gpu.convert_layout %arg1 : tensor<1x128x128xf16, #blocked> -> tensor<1x128x128xf16, #mma>
+    %3 = triton_gpu.local_load %1 : !tt.memdesc<1x128x128xf16, #shared, #triton_gpu.shared_memory> -> tensor<1x128x128xf16, #triton_gpu.dot_op<{opIdx = 0, parent = #mma, kWidth = 4}>>
+    tt.return
+  }
+}
+
+// -----
+
+// Check that optimization triggers with custom LDS limit and do not triggers with default one
+// CHECK-LABEL: alloc_convert_32k_limit
+// CHECK: %0 = triton_gpu.local_alloc %arg0 : {{.*}}#blocked{{.*}}#shared
+// CHECK: %1 = triton_gpu.convert_layout %arg1 : {{.*}}#blocked{{.*}}#mma
+// CHECK: %2 = triton_gpu.local_load %0 : {{.*}}#shared{{.*}}#triton_gpu.dot_op<{opIdx = 0, parent = #mma, kWidth = 4}>>
+// CHECK-32KLIMIT-LABEL: alloc_convert_32k_limit
+// CHECK-32KLIMIT: %0 = triton_gpu.local_alloc %arg0 : {{.*}}#blocked{{.*}}#shared
+// CHECK-32KLIMIT: %1 = triton_gpu.convert_layout %arg1 : {{.*}}#blocked{{.*}}#blocked1
+// CHECK-32KLIMIT: %2 = triton_gpu.convert_layout %1 : {{.*}}#blocked1{{.*}}#mma
+// CHECK-32KLIMIT: %3 = triton_gpu.local_load %0 : {{.*}}#shared{{.*}}#triton_gpu.dot_op<{opIdx = 0, parent = #mma, kWidth = 4}>>
+#blocked = #triton_gpu.blocked<{sizePerThread = [4, 1], threadsPerWarp = [16, 4], warpsPerCTA = [1, 8], order = [0, 1]}>
+#mma = #triton_gpu.amd_mfma<{versionMajor = 2, versionMinor = 0, warpsPerCTA = [1, 8], instrShape = [32, 32], isTransposed = false}>
+#shared = #triton_gpu.shared<{vec = 4, perPhase = 1, maxPhase = 16, order = [0, 1], hasLeadingOffset = false}>
+module attributes {"triton_gpu.num-warps" = 8 : i32, "triton_gpu.threads-per-warp" = 64 : i32} {
+  tt.func public @alloc_convert_32k_limit(%arg0: tensor<64x128xf16, #blocked>, %arg1: tensor<64x128xf16, #blocked>) attributes {noinline = false} {
+    %1 = triton_gpu.local_alloc %arg0 : (tensor<64x128xf16, #blocked>) -> !tt.memdesc<64x128xf16, #shared, #triton_gpu.shared_memory>
+    %2 = triton_gpu.convert_layout %arg1 : tensor<64x128xf16, #blocked> -> tensor<64x128xf16, #mma>
+    %3 = triton_gpu.local_load %1 : !tt.memdesc<64x128xf16, #shared, #triton_gpu.shared_memory> -> tensor<64x128xf16, #triton_gpu.dot_op<{opIdx = 0, kWidth = 4, parent = #mma}>>
+    tt.return
+  }
+}

third_party/amd/CMakeLists.txt

@@ -2,6 +2,7 @@ include_directories(${CMAKE_CURRENT_SOURCE_DIR}/include)
 include_directories(${CMAKE_CURRENT_BINARY_DIR}/include)
 add_subdirectory(include)
 add_subdirectory(lib)
+add_subdirectory(unittest)
 if(TRITON_BUILD_PYTHON_MODULE)
   add_triton_plugin(TritonAMD ${CMAKE_CURRENT_SOURCE_DIR}/python/triton_amd.cc LINK_LIBS TritonAMDGPUToLLVM TritonAMDGPUTransforms)
 endif()

third_party/amd/backend/compiler.py

@@ -169,6 +169,9 @@ def make_llir(src, metadata, options):
         pm = ir.pass_manager(mod.context)
         pm.enable_debug()
         amd.passes.ttgpuir.add_decompose_unsupported_conversions(pm, options.arch)
+        # experimental parameter, specifies custom LDS usage limit
+        custom_lds_size = 0
+        amd.passes.ttgpuir.add_optimize_lds_usage(pm, options.arch, custom_lds_size)
         passes.convert.add_scf_to_cf(pm)
         passes.convert.add_index_to_llvmir(pm)
 

third_party/amd/include/TritonAMDGPUToLLVM/Passes.h

@@ -22,6 +22,8 @@ namespace AMD {
 std::unique_ptr<OperationPass<ModuleOp>>
 createDecomposeUnsupportedConversionsPass(StringRef targetArch);
 
+std::unique_ptr<OperationPass<ModuleOp>>
+createOptimizeLDSUsagePass(StringRef arch, int32_t customLDSLimit = 0);
 } // namespace AMD
 
 std::unique_ptr<OperationPass<ModuleOp>>

third_party/amd/include/TritonAMDGPUToLLVM/Passes.td

@@ -13,6 +13,18 @@ def DecomposeUnsupportedAMDConversions : Pass<"decompose-unsupported-amd-convers
     ];
 }
 
+def OptimizeAMDLDSUsage : Pass<"optimize-amd-lds-usage", "mlir::ModuleOp"> {
+    let summary = "Minimize LDS usage";
+    let constructor = "mlir::triton::AMD::createOptimizeLDSUsagePass(\"\")";
+
+    let options = [
+        Option<"targetArch", "target-arch", "std::string", /*default*/"",
+               "gfx target device architecture, e.g., gfx942">,
+        Option<"customLDSLimit", "lds-limit", "int", /*default*/"0",
+               "custom limit of LDS consumption, if not provided, maximum LDS size is used">,
+    ];
+}
+
 def ConvertTritonAMDGPUToLLVM : Pass<"convert-triton-amdgpu-to-llvm", "mlir::ModuleOp"> {
     let summary = "Convert TritonGPU to LLVM";
     let constructor = "mlir::triton::createConvertTritonAMDGPUToLLVMPass(\"\", /*ftz=*/true)";

third_party/amd/lib/TritonAMDGPUToLLVM/CMakeLists.txt

@@ -15,6 +15,8 @@ add_triton_library(TritonAMDGPUToLLVM
     TargetInfo.cpp
     TargetUtils.cpp
     DecomposeUnsupportedConversions.cpp
+    OptimizeLDSUsage.cpp
+    OptimizeLDSUtility.cpp
     SPMDOpToLLVM.cpp
 
     DEPENDS