Skip to content

Conversation

@castigli
Copy link
Contributor

@castigli castigli commented Oct 28, 2025

This PR extends the nvvm.mma ops to support fp64 type.
The extension requires special handling of the return type for load ops for fragment a and b since they return a scalar instead of a struct.

@github-actions
Copy link

Thank you for submitting a Pull Request (PR) to the LLVM Project!

This PR will be automatically labeled and the relevant teams will be notified.

If you wish to, you can add reviewers by using the "Reviewers" section on this page.

If this is not working for you, it is probably because you do not have write permissions for the repository. In which case you can instead tag reviewers by name in a comment by using @ followed by their GitHub username.

If you have received no comments on your PR for a week, you can request a review by "ping"ing the PR by adding a comment “Ping”. The common courtesy "ping" rate is once a week. Please remember that you are asking for valuable time from other developers.

If you have further questions, they may be answered by the LLVM GitHub User Guide.

You can also ask questions in a comment on this PR, on the LLVM Discord or on the forums.

@llvmbot
Copy link
Member

llvmbot commented Oct 28, 2025

@llvm/pr-subscribers-mlir-llvm
@llvm/pr-subscribers-mlir-gpu

@llvm/pr-subscribers-mlir

Author: Giacomo Castiglioni (castigli)

Changes

This PR extends the gpu.subgroup_mma and nvvm.mma ops to support fp64 type.
The extension requires special handling of the return type for load ops for fragment a and b since they return a scalar instead of a struct.


Patch is 20.18 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/165380.diff

10 Files Affected:

  • (modified) mlir/include/mlir/Conversion/GPUToNVVM/GPUToNVVMPass.h (+1-1)
  • (modified) mlir/include/mlir/Dialect/GPU/IR/GPUBase.td (+1-1)
  • (modified) mlir/include/mlir/Dialect/GPU/IR/GPUOps.td (+4-4)
  • (modified) mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td (+14-2)
  • (modified) mlir/lib/Conversion/GPUToNVVM/WmmaOpsToNvvm.cpp (+42-10)
  • (modified) mlir/lib/Dialect/GPU/IR/GPUDialect.cpp (+2-2)
  • (modified) mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp (+14)
  • (modified) mlir/test/Conversion/GPUToNVVM/wmma-ops-to-nvvm.mlir (+22)
  • (added) mlir/test/Integration/GPU/CUDA/TensorCore/wmma-matmul-f64.mlir (+70)
  • (modified) mlir/test/Target/LLVMIR/nvvmir.mlir (+37)
diff --git a/mlir/include/mlir/Conversion/GPUToNVVM/GPUToNVVMPass.h b/mlir/include/mlir/Conversion/GPUToNVVM/GPUToNVVMPass.h
index 4c8abea680b66..48982ac6efe7c 100644
--- a/mlir/include/mlir/Conversion/GPUToNVVM/GPUToNVVMPass.h
+++ b/mlir/include/mlir/Conversion/GPUToNVVM/GPUToNVVMPass.h
@@ -27,7 +27,7 @@ class MMAMatrixType;
 #define GEN_PASS_DECL_CONVERTGPUOPSTONVVMOPS
 #include "mlir/Conversion/Passes.h.inc"
 
-LLVM::LLVMStructType convertMMAToLLVMType(gpu::MMAMatrixType type);
+Type convertMMAToLLVMType(gpu::MMAMatrixType type);
 
 /// Configure target to convert from the GPU dialect to NVVM.
 void configureGpuToNVVMConversionLegality(ConversionTarget &target);
diff --git a/mlir/include/mlir/Dialect/GPU/IR/GPUBase.td b/mlir/include/mlir/Dialect/GPU/IR/GPUBase.td
index 860f893367203..2c29bb8a01a41 100644
--- a/mlir/include/mlir/Dialect/GPU/IR/GPUBase.td
+++ b/mlir/include/mlir/Dialect/GPU/IR/GPUBase.td
@@ -114,7 +114,7 @@ def GPU_MMAMatrix : DialectType<
   GPU_Dialect, IsMMAMatrixTypePred, "MMAMatrix type">;
 
 // Memref type acceptable to gpu.subgroup_mma_{load|store}_matrix ops.
-def GPU_MMAMemRef : MemRefOf<[I8, I32, F16, F32, VectorOfRankAndType<[1], [I8, I32, F16, F32]>]>;
+def GPU_MMAMemRef : MemRefOf<[I8, I32, F16, F32, F64, VectorOfRankAndType<[1], [I8, I32, F16, F32, F64]>]>;
 
 class MMAMatrixOf<list<Type> allowedTypes> :
   ContainerType<AnyTypeOf<allowedTypes>, IsMMAMatrixTypePred,
diff --git a/mlir/include/mlir/Dialect/GPU/IR/GPUOps.td b/mlir/include/mlir/Dialect/GPU/IR/GPUOps.td
index a6c6038e1e224..5c7df25c58cde 100644
--- a/mlir/include/mlir/Dialect/GPU/IR/GPUOps.td
+++ b/mlir/include/mlir/Dialect/GPU/IR/GPUOps.td
@@ -1872,7 +1872,7 @@ def GPU_SubgroupMmaStoreMatrixOp : GPU_Op<"subgroup_mma_store_matrix",
     ```
   }];
 
-  let arguments = (ins Arg<MMAMatrixOf<[SI8, UI8, I32, F16, F32]>>:$src,
+  let arguments = (ins Arg<MMAMatrixOf<[SI8, UI8, I32, F16, F32, F64]>>:$src,
                   Arg<GPU_MMAMemRef, "",[MemWriteAt<0, FullEffect>]>:$dstMemref,
                   Variadic<Index>:$indices,
                   IndexAttr:$leadDimension,
@@ -1919,9 +1919,9 @@ def GPU_SubgroupMmaComputeOp
     ```
   }];
 
-  let arguments = (ins Arg<MMAMatrixOf<[SI8, UI8, F16, F32]>>:$opA,
-                  Arg<MMAMatrixOf<[SI8, UI8, F16, F32]>>:$opB,
-                  Arg<MMAMatrixOf<[I32, F16, F32]>>:$opC,
+  let arguments = (ins Arg<MMAMatrixOf<[SI8, UI8, F16, F32, F64]>>:$opA,
+                  Arg<MMAMatrixOf<[SI8, UI8, F16, F32, F64]>>:$opB,
+                  Arg<MMAMatrixOf<[I32, F16, F32, F64]>>:$opC,
                   OptionalAttr<UnitAttr>:$a_transpose,
                   OptionalAttr<UnitAttr>:$b_transpose);
 
diff --git a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
index 4f483859ac18d..cccdc2c368d6d 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
@@ -2014,6 +2014,9 @@ class MMA_LDST_OPS<list<GEOM> Geom, list<string> Frags, list<string> Types> {
 // llvm supports and can be extended as needed.
 class NVVM_MMA_OPS {
   // "wmma" operations
+  list<list<WMMA_REGS>> fp64_wmma_ops = MMA_OPS<
+            [GEOM<8, 8, 4>],
+            ["f64"], [], ["f64"], []>.ret;
   list<list<WMMA_REGS>> tf32_wmma_ops = MMA_OPS<
             [GEOM<16, 16, 8>],
             ["tf32"], [], ["f32"], []>.ret;
@@ -2024,6 +2027,7 @@ class NVVM_MMA_OPS {
             [GEOM<16, 16, 16>, GEOM<32, 8, 16>, GEOM<8, 32, 16>],
             ["s8","u8"], [], ["s32"], []>.ret;
   list<list<WMMA_REGS>> all_wmma_ops = !listconcat(
+            fp64_wmma_ops,
             tf32_wmma_ops,
             fp_wmma_ops,
             i8_wmma_ops);
@@ -2040,9 +2044,17 @@ class NVVM_MMA_OPS {
   list<WMMA_REGS> ldst_tf32_cd_ops = MMA_LDST_OPS<
             [GEOM<16, 16, 8>],
             ["c", "d"], ["f32"]>.ret;
+  list<WMMA_REGS> ldst_f64_ab_ops = MMA_LDST_OPS<
+            [GEOM<8, 8, 4>],
+            ["a", "b"], ["f64"]>.ret;
+  list<WMMA_REGS> ldst_f64_cd_ops = MMA_LDST_OPS<
+            [GEOM<8, 8, 4>],
+            ["c", "d"], ["f64"]>.ret;
   list<WMMA_REGS> all_ldst_ops = !listconcat(ldst_ab_ops, ldst_cd_ops,
                                              ldst_tf32_ab_ops,
-                                             ldst_tf32_cd_ops);
+                                             ldst_tf32_cd_ops, 
+                                             ldst_f64_ab_ops,
+                                             ldst_f64_cd_ops);
   // Separate A/B/C fragments (loads) from D (stores).
   list<WMMA_REGS> all_ld_ops = !filter(op, all_ldst_ops, !ne(op.frag, "d"));
   list<WMMA_REGS> all_st_ops = !filter(op, all_ldst_ops, !eq(op.frag, "d"));
@@ -2349,7 +2361,7 @@ def MMAFragAttr : EnumAttr<NVVM_Dialect, MMAFrag, "mma_frag"> {
 }
 
 def NVVM_WMMALoadOp: NVVM_Op<"wmma.load">,
-  Results<(outs LLVM_AnyStruct:$res)>,
+  Results<(outs AnyTypeOf<[LLVM_AnyStruct, F64]>:$res)>,
   Arguments<(ins LLVM_AnyPointer: $ptr, I32: $stride, I32Attr:$m,
              I32Attr:$n, I32Attr:$k, MMALayoutAttr:$layout,
              MMATypesAttr:$eltype, MMAFragAttr:$frag)> {
diff --git a/mlir/lib/Conversion/GPUToNVVM/WmmaOpsToNvvm.cpp b/mlir/lib/Conversion/GPUToNVVM/WmmaOpsToNvvm.cpp
index 99c059cb03299..fb1a37a03fe4d 100644
--- a/mlir/lib/Conversion/GPUToNVVM/WmmaOpsToNvvm.cpp
+++ b/mlir/lib/Conversion/GPUToNVVM/WmmaOpsToNvvm.cpp
@@ -17,6 +17,7 @@
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
 #include "mlir/Dialect/LLVMIR/NVVMDialect.h"
 #include "mlir/IR/TypeUtilities.h"
+#include "mlir/IR/Types.h"
 
 using namespace mlir;
 
@@ -57,7 +58,8 @@ static NVVM::MMATypes getElementType(gpu::MMAMatrixType type) {
   if (type.getElementType().isF32())
     return type.getOperand() == "COp" ? NVVM::MMATypes::f32
                                       : NVVM::MMATypes::tf32;
-
+  if (type.getElementType().isF64())
+    return NVVM::MMATypes::f64;
   if (type.getElementType().isSignedInteger(8))
     return NVVM::MMATypes::s8;
   if (type.getElementType().isUnsignedInteger(8))
@@ -212,8 +214,13 @@ struct WmmaMmaOpToNVVMLowering
     // then passed on to the intrinsic call. Emit llvm ops to extract individual
     // values form lowered memrefs.
     SmallVector<Value> unpackedOps;
-
     auto unpackOp = [&](Value operand) {
+      // f64 a and b fragments are not structs but scalars.
+      if (!isa<LLVM::LLVMStructType>(operand.getType())) {
+        unpackedOps.push_back(operand);
+        return;
+      }
+      // every other type is lowered to an LLVM struct, extract the values.
       auto structType = cast<LLVM::LLVMStructType>(operand.getType());
       for (size_t i = 0, e = structType.getBody().size(); i < e; ++i) {
         Value toUse = LLVM::ExtractValueOp::create(rewriter, loc, operand, i);
@@ -276,10 +283,16 @@ struct WmmaConstantOpToNVVMLowering
       return failure();
     Location loc = subgroupMmaConstantOp.getLoc();
     Value cst = adaptor.getOperands()[0];
-    LLVM::LLVMStructType type = convertMMAToLLVMType(
+    Type type = convertMMAToLLVMType(
         cast<gpu::MMAMatrixType>(subgroupMmaConstantOp.getType()));
+    // If the element is not a struct, it means it's a scalar f64.
+    LLVM::LLVMStructType structType = dyn_cast<LLVM::LLVMStructType>(type);
+    if (!structType) {
+      rewriter.replaceOp(subgroupMmaConstantOp, cst);
+      return success();
+    }
     // If the element type is a vector create a vector from the operand.
-    if (auto vecType = dyn_cast<VectorType>(type.getBody()[0])) {
+    if (auto vecType = dyn_cast<VectorType>(structType.getBody()[0])) {
       Value vecCst = LLVM::PoisonOp::create(rewriter, loc, vecType);
       for (int64_t vecEl = 0; vecEl < vecType.getNumElements(); vecEl++) {
         Value idx = LLVM::ConstantOp::create(rewriter, loc,
@@ -289,8 +302,8 @@ struct WmmaConstantOpToNVVMLowering
       }
       cst = vecCst;
     }
-    Value matrixStruct = LLVM::PoisonOp::create(rewriter, loc, type);
-    for (size_t i : llvm::seq(size_t(0), type.getBody().size())) {
+    Value matrixStruct = LLVM::PoisonOp::create(rewriter, loc, structType);
+    for (size_t i : llvm::seq(size_t(0), structType.getBody().size())) {
       matrixStruct =
           LLVM::InsertValueOp::create(rewriter, loc, matrixStruct, cst, i);
     }
@@ -354,10 +367,24 @@ struct WmmaElementwiseOpToNVVMLowering
       return failure();
     Location loc = subgroupMmaElementwiseOp.getLoc();
     size_t numOperands = adaptor.getOperands().size();
-    LLVM::LLVMStructType destType = convertMMAToLLVMType(
+    Type destType = convertMMAToLLVMType(
         cast<gpu::MMAMatrixType>(subgroupMmaElementwiseOp.getType()));
-    Value matrixStruct = LLVM::PoisonOp::create(rewriter, loc, destType);
-    for (size_t i = 0, e = destType.getBody().size(); i < e; ++i) {
+
+    // If the element is not a struct, it means it's a scalar f64.
+    LLVM::LLVMStructType structDestTy = dyn_cast<LLVM::LLVMStructType>(destType);
+    if (!structDestTy) {
+      SmallVector<Value> operands;
+      for (auto operand : adaptor.getOperands()) {
+        operands.push_back(operand);
+      }
+      Value element =
+          createScalarOp(rewriter, loc, subgroupMmaElementwiseOp.getOpType(),
+                         operands);
+      rewriter.replaceOp(subgroupMmaElementwiseOp, element);
+      return success();
+    }
+    Value matrixStruct = LLVM::PoisonOp::create(rewriter, loc, structDestTy);
+    for (size_t i = 0, e = structDestTy.getBody().size(); i < e; ++i) {
       SmallVector<Value> extractedOperands;
       for (size_t opIdx = 0; opIdx < numOperands; opIdx++) {
         extractedOperands.push_back(LLVM::ExtractValueOp::create(
@@ -377,13 +404,18 @@ struct WmmaElementwiseOpToNVVMLowering
 } // namespace
 
 /// Return the LLVMStructureType corresponding to the MMAMatrixType `type`.
-LLVM::LLVMStructType mlir::convertMMAToLLVMType(gpu::MMAMatrixType type) {
+Type mlir::convertMMAToLLVMType(gpu::MMAMatrixType type) {
   NVVM::MMAFrag frag = convertOperand(type.getOperand());
   NVVM::MMATypes eltType = getElementType(type);
   auto nRow = type.getShape()[0];
   auto nCol = type.getShape()[1];
   std::pair<Type, unsigned> typeInfo =
       NVVM::inferMMAType(eltType, frag, nRow, nCol, type.getContext());
+  // Special handling for f64 a and b fragments
+  Type f64Ty = Float64Type::get(type.getContext());
+  if (typeInfo.first == f64Ty && typeInfo.second == 1) {
+    return f64Ty;
+  }
   return LLVM::LLVMStructType::getLiteral(
       type.getContext(), SmallVector<Type, 8>(typeInfo.second, typeInfo.first));
 }
diff --git a/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp b/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
index b5f8ddaadacdf..0dd9b6adea954 100644
--- a/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
+++ b/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp
@@ -208,7 +208,7 @@ Type MMAMatrixType::getElementType() const { return getImpl()->elementType; }
 StringRef MMAMatrixType::getOperand() const { return getImpl()->getOperand(); }
 
 bool MMAMatrixType::isValidElementType(Type elementType) {
-  return elementType.isF16() || elementType.isF32() ||
+  return elementType.isF16() || elementType.isF32() || elementType.isF64() ||
          elementType.isUnsignedInteger(8) || elementType.isSignedInteger(8) ||
          elementType.isInteger(32);
 }
@@ -225,7 +225,7 @@ MMAMatrixType::verifyInvariants(function_ref<InFlightDiagnostic()> emitError,
 
   if (!MMAMatrixType::isValidElementType(elementType))
     return emitError()
-           << "MMAMatrixType elements must be SI8, UI8, I32, F16, or F32";
+           << "MMAMatrixType elements must be SI8, UI8, I32, F16, F32, or F64";
 
   return success();
 }
diff --git a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
index f0de4dbcc1d4b..c665cc4201049 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
@@ -896,6 +896,12 @@ std::pair<mlir::Type, unsigned> NVVM::inferMMAType(NVVM::MMATypes type,
   } else if (type == NVVM::MMATypes::f32) {
     elementType = builder.getF32Type();
     numberElements = 8;
+  } else if (type == NVVM::MMATypes::f64) {
+    elementType = builder.getF64Type();
+    if (frag == NVVM::MMAFrag::a || frag == NVVM::MMAFrag::b)
+      numberElements = 1;
+    else
+      numberElements = 2;
   } else if (type == NVVM::MMATypes::tf32) {
     elementType = builder.getI32Type();
     numberElements = 4;
@@ -954,6 +960,14 @@ LogicalResult NVVM::WMMALoadOp::verify() {
     return emitOpError() << "invalid attribute combination";
   std::pair<Type, unsigned> typeInfo = inferMMATypeFromMNK(
       getEltype(), getFrag(), getM(), getN(), getK(), getContext());
+  // Special case for f64 fragments
+  Type f64Ty = Float64Type::get(getContext());
+  if (typeInfo.first == f64Ty && typeInfo.second == 1) {
+      if (getType() != f64Ty)
+        return emitOpError("expected destination type to be f64");
+    return success();
+  }
+  // Everything else is a struct
   Type dstType = LLVM::LLVMStructType::getLiteral(
       getContext(), SmallVector<Type, 8>(typeInfo.second, typeInfo.first));
   if (getType() != dstType)
diff --git a/mlir/test/Conversion/GPUToNVVM/wmma-ops-to-nvvm.mlir b/mlir/test/Conversion/GPUToNVVM/wmma-ops-to-nvvm.mlir
index b479467efc208..83b5fb5e6ea54 100644
--- a/mlir/test/Conversion/GPUToNVVM/wmma-ops-to-nvvm.mlir
+++ b/mlir/test/Conversion/GPUToNVVM/wmma-ops-to-nvvm.mlir
@@ -79,6 +79,28 @@ gpu.module @test_module {
 
 // -----
 
+gpu.module @test_module {
+
+  // CHECK-LABEL: func @gpu_wmma_f64_load_op() ->
+  // CHECK-SAME: f64
+  // CHECK32-LABEL: func @gpu_wmma_f64_load_op() ->
+  func.func @gpu_wmma_f64_load_op() -> (!gpu.mma_matrix<8x4xf64, "AOp">) {
+    %wg = memref.alloca() {alignment = 32} : memref<32x32xf64, 3>
+    %i = arith.constant 16 : index
+    %j = arith.constant 16 : index
+    %0 = gpu.subgroup_mma_load_matrix %wg[%i, %j] {leadDimension = 32 : index} : memref<32x32xf64, 3> -> !gpu.mma_matrix<8x4xf64, "AOp">
+    return %0 : !gpu.mma_matrix<8x4xf64, "AOp">
+    // CHECK: %[[MUL:.*]] = llvm.mul %{{.*}}, %{{.*}} : i64
+    // CHECK: %[[ADD:.*]] = llvm.add %[[MUL]], %{{.*}} : i64
+    // CHECK: %[[GEP:.*]] = llvm.getelementptr %{{.*}}[%[[ADD]]] : (!llvm.ptr<3>, i64) -> !llvm.ptr<3>, f64
+    // CHECK: %[[C32_I32:.*]] = llvm.mlir.constant(32 : index) : i32
+    // CHECK: %[[LOAD:.*]] = nvvm.wmma.load %[[GEP]], %[[C32_I32]] {eltype = #nvvm.mma_type<f64>, frag = #nvvm.mma_frag<a>, k = 4 : i32, layout = #nvvm.mma_layout<row>, m = 8 : i32, n = 8 : i32} : (!llvm.ptr<3>) -> f64
+    // CHECK: llvm.return %[[LOAD]] : f64
+  }
+}
+
+// -----
+
 gpu.module @test_module {
 
   // CHECK-LABEL: func @gpu_wmma_store_op
diff --git a/mlir/test/Integration/GPU/CUDA/TensorCore/wmma-matmul-f64.mlir b/mlir/test/Integration/GPU/CUDA/TensorCore/wmma-matmul-f64.mlir
new file mode 100644
index 0000000000000..a37af5def8c42
--- /dev/null
+++ b/mlir/test/Integration/GPU/CUDA/TensorCore/wmma-matmul-f64.mlir
@@ -0,0 +1,70 @@
+// RUN: mlir-opt %s \
+// RUN: | mlir-opt -gpu-lower-to-nvvm-pipeline="cubin-chip=sm_80 cubin-format=%gpu_compilation_format" \
+// RUN: | mlir-runner \
+// RUN:   --shared-libs=%mlir_cuda_runtime \
+// RUN:   --shared-libs=%mlir_runner_utils \
+// RUN:   --entry-point-result=void \
+// RUN: | FileCheck %s
+
+func.func @main() {
+  %a = memref.alloc() : memref<8x4xf64>
+  %b = memref.alloc() : memref<4x8xf64>
+  %c = memref.alloc() : memref<8x8xf64>
+  %d = memref.alloc() : memref<8x8xf64>
+
+  %f1 = arith.constant 1.0e+00 : f64
+  %fcst = arith.constant 3.14e+00 : f64
+  %c0 = arith.constant 0 : index
+  %c8 = arith.constant 8 : index
+  %c4 = arith.constant 4 : index
+  %c1 = arith.constant 1 : index
+  %c32 = arith.constant 32 : index
+
+  // Initialize the Input matrixes with ones.
+  scf.for %arg0 = %c0 to %c8 step %c1 {
+    scf.for %arg1 = %c0 to %c4 step %c1 {
+      memref.store %f1, %a[%arg0, %arg1] : memref<8x4xf64>
+      memref.store %f1, %b[%arg1, %arg0] : memref<4x8xf64>
+    }
+  }
+  // Initialize the accumulator matrix with zeros.
+  scf.for %arg0 = %c0 to %c8 step %c1 {
+    scf.for %arg1 = %c0 to %c8 step %c1 {
+      memref.store %fcst, %c[%arg0, %arg1] : memref<8x8xf64>
+    }
+  }
+
+  %2 = memref.cast %a : memref<8x4xf64> to memref<*xf64>
+  %20 = memref.cast %b : memref<4x8xf64> to memref<*xf64>
+  %33 = memref.cast %c : memref<8x8xf64> to memref<*xf64>
+  %34 = memref.cast %d : memref<8x8xf64> to memref<*xf64>
+
+  gpu.host_register %2 : memref<*xf64>
+  gpu.host_register %20 : memref<*xf64>
+  gpu.host_register %33 : memref<*xf64>
+
+  gpu.launch blocks(%bx, %by, %bz) in (%grid_x = %c1, %grid_y = %c1, %grid_z = %c1)
+             threads(%tx, %ty, %tz) in (%block_x = %c32, %block_y = %c1, %block_z = %c1) {
+    %A = gpu.subgroup_mma_load_matrix %a[%c0, %c0] {leadDimension = 4 : index} : memref<8x4xf64> -> !gpu.mma_matrix<8x4xf64, "AOp">
+    %B = gpu.subgroup_mma_load_matrix %b[%c0, %c0] {leadDimension = 8 : index} : memref<4x8xf64> -> !gpu.mma_matrix<4x8xf64, "BOp">
+    %C = gpu.subgroup_mma_load_matrix %c[%c0, %c0] {leadDimension = 8 : index} : memref<8x8xf64> -> !gpu.mma_matrix<8x8xf64, "COp">
+
+    %R = gpu.subgroup_mma_compute %A, %B, %C : !gpu.mma_matrix<8x4xf64, "AOp">, !gpu.mma_matrix<4x8xf64, "BOp"> -> !gpu.mma_matrix<8x8xf64, "COp">
+
+    gpu.subgroup_mma_store_matrix %R, %d[%c0, %c0] {leadDimension = 8 : index}: !gpu.mma_matrix<8x8xf64, "COp">, memref<8x8xf64>
+    gpu.terminator
+  }
+  // Print the memref after computation.
+  call @printMemrefF64(%34) : (memref<*xf64>) -> ()
+  // CHECK: [7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14],
+  // CHECK-NEXT: [7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14],
+  // CHECK-NEXT: [7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14],
+  // CHECK-NEXT: [7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14],
+  // CHECK-NEXT: [7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14],
+  // CHECK-NEXT: [7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14],
+  // CHECK-NEXT: [7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14],
+  // CHECK-NEXT: [7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14,   7.14]
+  return
+}
+
+func.func private @printMemrefF64(memref<*xf64>)
diff --git a/mlir/test/Target/LLVMIR/nvvmir.mlir b/mlir/test/Target/LLVMIR/nvvmir.mlir
index 594ae4849e3eb..388ebe859a249 100644
--- a/mlir/test/Target/LLVMIR/nvvmir.mlir
+++ b/mlir/test/Target/LLVMIR/nvvmir.mlir
@@ -463,6 +463,43 @@ llvm.func @nvvm_wmma_mma(%0 : i32, %1 : i32, %2 : i32, %3 : i32, %4 : i32, %5 :
   llvm.return
 }
 
+// CHECK-LABEL: @nvvm_wmma_load_a_f64
+llvm.func @nvvm_wmma_load_a_f64(%arg0: !llvm.ptr, %arg1 : i32) {
+  // CHECK: call double @llvm.nvvm.wmma.m8n8k4.load.a.row.stride.f64.p0(ptr %{{.*}}, i32 %{{.*}})
+  %0 = nvvm.wmma.load %arg0, %arg1
+    {eltype = #nvvm.mma_type<f64>, frag = #nvvm.mma_frag<a>, k = 4 : i32, layout = #nvvm.mma_layout<row>, m = 8 : i32, n = 8 : i32}
+    : (!llvm.ptr) -> f64
+  llvm.return
+}
+
+// CHECK-LABEL: @nvvm_wmma_load_c_f64
+llvm.func @nvvm_wmma_load_c_f64(%arg0: !llvm.ptr, %arg1 : i32) {
+  // CHECK: call { double, double } @llvm.nvvm.wmma.m8n8k4.load.c.row.stride.f64.p0(ptr %{{.*}}, i32 %{{.*}})
+  %0 = nvvm.wmma.load %arg0, %arg1
+    {eltype = #nvvm.mma_type<f64>, frag = #nvvm.mma_frag<c>, k = 4 : i32, layout = #nvvm.mma_layout<row>, m = 8 : i32, n = 8 : i32}
+    : (!llvm.ptr) -> !llvm.struct<(f64, f64)>
+  llvm.return
+}
+
+// CHECK-LABEL: @nvvm_wmma_mma_f64
+llvm.func @nvvm_wmma_mma_f64(%0 : f64, %1 : f64, %2 : f64, %3 : f64) {
+  // CHECK: { double, double } @llvm.nvvm.wmma.mm8n8k4.mma.row.col.f64(f64 %{{.*}}, f64 %{{.*}}, f64 %{{.*}}, f64 %{{.*}})
+  %r = nvvm.wmma.mma %0, %1, %2, %3
+    {eltypeA = #nvvm.mma_type<f64>, eltypeB = #nvvm.mma_type<f64>, k = 4 : i32, layoutA = #nvvm.mma_layout<row>, layoutB = #nvvm.mma_layout<col>, m = 8 : i32, n = 8 : i32}
+    : (f64, f64, f64, f64)
+    -> !llvm.struct<(f64, f64)>
+  llvm.return
+}
+
+// CHECK-LABEL: @nvvm_wmma_store_d_f64
+llvm.func @nvvm_wmma_store_d_f64(%arg0: !llvm.ptr, %arg1 : i32, %arg2 : f64, %arg3 : f64) {
+  // CHECK: call void @llvm.nvvm.wmma.m8n8k4.store.d.row.stride.f64.p0(ptr %{{.*}}, f64 %{{.*}}, f64 %{{.*}}, i32 %{{.*}})
+  nvvm.wmma.store %arg0, %arg1, %arg2, %arg3
+    {eltype = #nvvm.mma_type<f64>, k = 4 : i32, layout = #nvvm.mma_layout<row>, m = 8 : i32, n = 8 : i32}
+    : !llvm.ptr, f64, f64
+  llvm.return
+}
+
 // CHECK-LABEL: @cp_...
[truncated]

@castigli castigli changed the title Extend GPU and NVVM mma ops to support fp64 Extend NVVM mma ops to support fp64 Oct 29, 2025
@castigli castigli requested a review from grypp October 29, 2025 13:06
@grypp grypp requested a review from durga4github October 30, 2025 14:42
Copy link
Contributor

@durga4github durga4github left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

LGTM except for a test case ask.

@castigli
Copy link
Contributor Author

LGTM except for a test case ask.

I don't have write permission, whenever you have time, could you merge the PR for me?

@durga4github durga4github merged commit 0ed8e66 into llvm:main Oct 31, 2025
10 checks passed
@github-actions
Copy link

@castigli Congratulations on having your first Pull Request (PR) merged into the LLVM Project!

Your changes will be combined with recent changes from other authors, then tested by our build bots. If there is a problem with a build, you may receive a report in an email or a comment on this PR.

Please check whether problems have been caused by your change specifically, as the builds can include changes from many authors. It is not uncommon for your change to be included in a build that fails due to someone else's changes, or infrastructure issues.

How to do this, and the rest of the post-merge process, is covered in detail here.

If your change does cause a problem, it may be reverted, or you can revert it yourself. This is a normal part of LLVM development. You can fix your changes and open a new PR to merge them again.

If you don't get any reports, no action is required from you. Your changes are working as expected, well done!

ckoparkar added a commit to ckoparkar/llvm-project that referenced this pull request Oct 31, 2025
* main:
  [SPIRV] Fix vector bitcast check in LegalizePointerCast (llvm#164997)
  [lldb][docs] Add troubleshooting section to scripting introduction
  [Sema] Fix parameter index checks on explicit object member functions (llvm#165586)
  To fix polymorphic pointer assignment in FORALL when LHS is unlimited polymorphic and RHS is intrinsic type target (llvm#164999)
  [CostModel][AArch64] Model cost of extract.last.active intrinsic (clastb) (llvm#165739)
  [MemProf] Select largest of matching contexts from profile (llvm#165338)
  [lldb][TypeSystem] Better support for _BitInt types (llvm#165689)
  [NVPTX] Move TMA G2S lowering to Tablegen (llvm#165710)
  [MLIR][NVVM] Extend NVVM mma ops to support fp64 (llvm#165380)
  [UTC] Support to test annotated IR (llvm#165419)
DEBADRIBASAK pushed a commit to DEBADRIBASAK/llvm-project that referenced this pull request Nov 3, 2025
This PR extends the  `nvvm.mma` ops to support fp64 type.
The extension requires special handling of the return type for load ops
for fragment `a` and `b` since they return a scalar instead of a struct.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Projects

None yet

Development

Successfully merging this pull request may close these issues.

4 participants