[Mlir-commits] [mlir] [MLIR][NVVM] Add support for converting	fp4/6/8 to fp16x2 (PR #162439)
    Srinivasa Ravi 
    llvmlistbot at llvm.org
       
    Fri Oct 10 01:18:54 PDT 2025
    
    
  
https://github.com/Wolfram70 updated https://github.com/llvm/llvm-project/pull/162439
>From d2ebae85ca5e44728b8117d1f47c5d512ce960b1 Mon Sep 17 00:00:00 2001
From: Srinivasa Ravi <srinivasar at nvidia.com>
Date: Wed, 8 Oct 2025 06:26:01 +0000
Subject: [PATCH 1/6] [MLIR][NVVM] Add support for converting fp4/6/8 to fp16x2
This change adds the following NVVM dialect Ops for converting fp4/6/8
to fp16x2:
- convert.f4x2.to.f16x2
- convert.f6x2.to.f16x2
- convert.f8x2.to.f16x2
- convert.f8x2.to.bf16x2
Tests are added in `convert_fp4x2.mlir`, `convert_fp6x2.mlir`, and
`convert_fp8x2.mlir`.
PTX Reference: https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt
---
 mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td   | 107 ++++++++++++++
 mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp    | 139 ++++++++++++++++++
 .../Target/LLVMIR/nvvm/convert_fp4x2.mlir     |  14 ++
 .../Target/LLVMIR/nvvm/convert_fp6x2.mlir     |  24 +++
 .../Target/LLVMIR/nvvm/convert_fp8x2.mlir     |  34 +++++
 5 files changed, 318 insertions(+)
 create mode 100644 mlir/test/Target/LLVMIR/nvvm/convert_fp4x2.mlir
diff --git a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
index e2a0331542742..5020af3992173 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
@@ -1832,6 +1832,113 @@ def NVVM_ConvertBF16x2ToF8x2Op : NVVM_Op<"convert.bf16x2.to.f8x2"> {
   }];
 }
 
+class NVVM_ConvertF8x2ToFP16x2Op_Base <string dstType>
+: NVVM_Op<"convert.f8x2.to." # !tolower(dstType) # "x2"> {
+  let summary = "Convert a pair of f8 inputs to " # !tolower(dstType) # "x2";
+  let description = [{
+    This Op converts the given f8 inputs in a i8x2 vector to }] # !tolower(dstType) # [{.
+
+    The result `dst` is represented as a vector of }] # !tolower(dstType) # [{ elements.
+
+    The `relu` attribute, when set, lowers to the '.relu' variant of
+    the cvt instruction.
+    
+    For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
+  }];
+  let results = (outs VectorOfLengthAndType<[2], [!cast<Type>(dstType)]>:$dst);
+  let arguments = !if(!eq(dstType, "F16"),
+    (ins VectorOfLengthAndType<[2], [I8]>:$src,
+         DefaultValuedAttr<BoolAttr, "false">:$relu,
+         TypeAttr:$srcType),
+    (ins VectorOfLengthAndType<[2], [I8]>:$src,
+         TypeAttr:$srcType));
+  let assemblyFormat = "$src attr-dict `:` type($src) `(` $srcType `)` `->` type($dst)";
+  let hasVerifier = 1;
+
+  let extraClassDeclaration = [{
+    static IDArgPair
+    getIntrinsicIDAndArgs(Operation &op, LLVM::ModuleTranslation &mt, 
+                          llvm::IRBuilderBase &builder);
+  }];
+
+  string llvmBuilder = [{
+    auto [intId, args] =
+    NVVM::ConvertF8x2To}] # dstType # [{x2Op::getIntrinsicIDAndArgs(*op, moduleTranslation, builder);
+    $dst = createIntrinsicCall(builder, intId, args);
+  }];
+}
+
+def NVVM_ConvertF8x2ToF16x2Op : NVVM_ConvertF8x2ToFP16x2Op_Base<"F16">;
+def NVVM_ConvertF8x2ToBF16x2Op : NVVM_ConvertF8x2ToFP16x2Op_Base<"BF16">;
+
+
+def NVVM_ConvertF6x2ToF16x2Op : NVVM_Op<"convert.f6x2.to.f16x2"> {
+  let summary = "Convert a pair of f6 inputs to f16x2";
+  let description = [{
+    This Op converts the given f6 inputs in a i8x2 vector to f16x2.
+
+    The result `dst` is represented as a vector of f16 elements.
+    
+    The `relu` attribute, when set, lowers to the '.relu' variant of
+    the cvt instruction.
+
+    For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
+  }];
+  let results = (outs VectorOfLengthAndType<[2], [F16]>:$dst);
+  let arguments = (ins VectorOfLengthAndType<[2], [I8]>:$src,
+         DefaultValuedAttr<BoolAttr, "false">:$relu,
+         TypeAttr:$srcType);
+  let assemblyFormat = "$src attr-dict `:` type($src) `(` $srcType `)` `->` type($dst)";
+  let hasVerifier = 1;
+
+  let extraClassDeclaration = [{
+    static IDArgPair
+    getIntrinsicIDAndArgs(Operation &op, LLVM::ModuleTranslation &mt, 
+                          llvm::IRBuilderBase &builder);
+  }];
+
+  string llvmBuilder = [{
+    auto [intId, args] =
+    NVVM::ConvertF6x2ToF16x2Op::getIntrinsicIDAndArgs(*op, moduleTranslation, builder);
+    $dst = createIntrinsicCall(builder, intId, args);
+  }];
+}
+
+def NVVM_ConvertF4x2ToF16x2Op : NVVM_Op<"convert.f4x2.to.f16x2"> {
+  let summary = "Convert a pair of f4 inputs to f16x2";
+  let description = [{
+    This Op converts the given f4 inputs packed in an i8 to f16x2.
+
+    The result `dst` is represented as a vector of f16 elements. The value 
+    converted from the lower 4 bits of `src` is stored in the first element of 
+    `dst` and the value converted from the upper 4 bits of `src` is stored in 
+    the second element of `dst`.
+
+    The `relu` attribute, when set, lowers to the '.relu' variant of
+    the cvt instruction.
+
+    For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
+  }];
+  let results = (outs VectorOfLengthAndType<[2], [F16]>:$dst);
+  let arguments = (ins I8:$src,
+         DefaultValuedAttr<BoolAttr, "false">:$relu,
+         TypeAttr:$srcType);
+  let assemblyFormat = "$src attr-dict `:` type($src) `(` $srcType `)` `->` type($dst)";
+  let hasVerifier = 1;
+
+  let extraClassDeclaration = [{
+    static IDArgPair
+    getIntrinsicIDAndArgs(Operation &op, LLVM::ModuleTranslation &mt, 
+                          llvm::IRBuilderBase &builder);
+  }];
+
+  string llvmBuilder = [{
+    auto [intId, args] =
+    NVVM::ConvertF4x2ToF16x2Op::getIntrinsicIDAndArgs(*op, moduleTranslation, builder);
+    $dst = createIntrinsicCall(builder, intId, args);
+  }];
+}
+
 //===----------------------------------------------------------------------===//
 // NVVM MMA Ops
 //===----------------------------------------------------------------------===//
diff --git a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
index 7f419a062201d..bd38db52179a6 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
@@ -309,6 +309,51 @@ LogicalResult ConvertBF16x2ToF8x2Op::verify() {
   return success();
 }
 
+LogicalResult ConvertF8x2ToF16x2Op::verify() {
+  mlir::MLIRContext *ctx = getContext();
+
+  if (!llvm::isa<Float8E4M3FNType, Float8E5M2Type>(getSrcType()))
+    return emitOpError("Only ")
+           << mlir::Float8E4M3FNType::get(ctx) << " and "
+           << mlir::Float8E5M2Type::get(ctx)
+           << " types are supported for conversions from f8x2 to f16x2.";
+
+  return success();
+}
+
+LogicalResult ConvertF8x2ToBF16x2Op::verify() {
+  mlir::MLIRContext *ctx = getContext();
+  if (!llvm::isa<Float8E8M0FNUType>(getSrcType()))
+    return emitOpError("Only ")
+           << mlir::Float8E8M0FNUType::get(ctx)
+           << " type is supported for conversions from f8x2 to bf16x2.";
+
+  return success();
+}
+
+LogicalResult ConvertF6x2ToF16x2Op::verify() {
+  mlir::MLIRContext *ctx = getContext();
+
+  if (!llvm::isa<Float6E2M3FNType, Float6E3M2FNType>(getSrcType()))
+    return emitOpError("Only ")
+           << mlir::Float6E2M3FNType::get(ctx) << " and "
+           << mlir::Float6E3M2FNType::get(ctx)
+           << " types are supported for conversions from f6x2 to f16x2.";
+
+  return success();
+}
+
+LogicalResult ConvertF4x2ToF16x2Op::verify() {
+  mlir::MLIRContext *ctx = getContext();
+
+  if (!llvm::isa<Float4E2M1FNType>(getSrcType()))
+    return emitOpError("Only ")
+           << mlir::Float4E2M1FNType::get(ctx)
+           << " type is supported for conversions from f4x2 to f16x2.";
+
+  return success();
+}
+
 LogicalResult BulkStoreOp::verify() {
   if (getInitVal() != 0)
     return emitOpError("only 0 is supported for initVal, got ") << getInitVal();
@@ -2106,6 +2151,100 @@ ConvertBF16x2ToF8x2Op::getIntrinsicID(NVVM::FPRoundingMode rnd,
   }
 }
 
+NVVM::IDArgPair ConvertF8x2ToF16x2Op::getIntrinsicIDAndArgs(
+    Operation &op, LLVM::ModuleTranslation &mt, llvm::IRBuilderBase &builder) {
+  auto curOp = cast<NVVM::ConvertF8x2ToF16x2Op>(op);
+  
+  bool hasRelu = curOp.getRelu();
+
+  llvm::Intrinsic::ID intId =
+      llvm::TypeSwitch<mlir::Type, llvm::Intrinsic::ID>(curOp.getSrcType())
+          .Case<Float8E4M3FNType>([&](Float8E4M3FNType type) {
+            return hasRelu
+                       ? llvm::Intrinsic::nvvm_e4m3x2_to_f16x2_rn_relu
+                       : llvm::Intrinsic::nvvm_e4m3x2_to_f16x2_rn;
+          })
+          .Case<Float8E5M2Type>([&](Float8E5M2Type type) {
+            return hasRelu
+                       ? llvm::Intrinsic::nvvm_e5m2x2_to_f16x2_rn_relu
+                       : llvm::Intrinsic::nvvm_e5m2x2_to_f16x2_rn;
+          })
+          .Default([](mlir::Type type) {
+            llvm_unreachable("Invalid type for ConvertF8x2ToF16x2Op");
+            return llvm::Intrinsic::not_intrinsic;
+          });
+
+  llvm::Value *packedI16 =
+      builder.CreateBitCast(mt.lookupValue(curOp.getSrc()),
+                            llvm::Type::getInt16Ty(builder.getContext()));
+
+  return {intId, {packedI16}};
+}
+
+NVVM::IDArgPair ConvertF8x2ToBF16x2Op::getIntrinsicIDAndArgs(
+    Operation &op, LLVM::ModuleTranslation &mt, llvm::IRBuilderBase &builder) {
+  auto curOp = cast<NVVM::ConvertF8x2ToBF16x2Op>(op);
+
+  llvm::Intrinsic::ID intId = llvm::Intrinsic::nvvm_ue8m0x2_to_bf16x2;
+  llvm::Value *packedI16 =
+      builder.CreateBitCast(mt.lookupValue(curOp.getSrc()),
+                            llvm::Type::getInt16Ty(builder.getContext()));
+
+  return {intId, {packedI16}};
+}
+
+NVVM::IDArgPair ConvertF6x2ToF16x2Op::getIntrinsicIDAndArgs(
+    Operation &op, LLVM::ModuleTranslation &mt, llvm::IRBuilderBase &builder) {
+  auto curOp = cast<NVVM::ConvertF6x2ToF16x2Op>(op);
+
+  bool hasRelu = curOp.getRelu();
+
+  llvm::Intrinsic::ID intId =
+      llvm::TypeSwitch<mlir::Type, llvm::Intrinsic::ID>(curOp.getSrcType())
+          .Case<Float6E2M3FNType>([&](Float6E2M3FNType type) {
+            return hasRelu ? llvm::Intrinsic::nvvm_e2m3x2_to_f16x2_rn_relu
+                           : llvm::Intrinsic::nvvm_e2m3x2_to_f16x2_rn;
+          })
+          .Case<Float6E3M2FNType>([&](Float6E3M2FNType type) {
+            return hasRelu ? llvm::Intrinsic::nvvm_e3m2x2_to_f16x2_rn_relu
+                           : llvm::Intrinsic::nvvm_e3m2x2_to_f16x2_rn;
+          })
+          .Default([](mlir::Type type) {
+            llvm_unreachable("Invalid type for ConvertF6x2ToF16x2Op");
+            return llvm::Intrinsic::not_intrinsic;
+          });
+
+  llvm::Value *packedI16 =
+      builder.CreateBitCast(mt.lookupValue(curOp.getSrc()),
+                            llvm::Type::getInt16Ty(builder.getContext()));
+
+  return {intId, {packedI16}};
+}
+
+NVVM::IDArgPair ConvertF4x2ToF16x2Op::getIntrinsicIDAndArgs(
+    Operation &op, LLVM::ModuleTranslation &mt, llvm::IRBuilderBase &builder) {
+  auto curOp = cast<NVVM::ConvertF4x2ToF16x2Op>(op);
+
+  bool hasRelu = curOp.getRelu();
+
+  llvm::Intrinsic::ID intId =
+      llvm::TypeSwitch<mlir::Type, llvm::Intrinsic::ID>(curOp.getSrcType())
+          .Case<Float4E2M1FNType>([&](Float4E2M1FNType type) {
+            return hasRelu ? llvm::Intrinsic::nvvm_e2m1x2_to_f16x2_rn_relu
+                           : llvm::Intrinsic::nvvm_e2m1x2_to_f16x2_rn;
+          })
+          .Default([](mlir::Type type) {
+            llvm_unreachable("Invalid type for ConvertF4x2ToF16x2Op");
+            return llvm::Intrinsic::not_intrinsic;
+          });
+
+  llvm::Value *extendedI16 =
+      builder.CreateZExt(mt.lookupValue(curOp.getSrc()),
+                         llvm::Type::getInt16Ty(builder.getContext()));
+
+  return {intId, {extendedI16}};
+}
+
 llvm::Intrinsic::ID
 Tcgen05AllocOp::getIntrinsicIDAndArgs(Operation &op,
                                       LLVM::ModuleTranslation &mt,
diff --git a/mlir/test/Target/LLVMIR/nvvm/convert_fp4x2.mlir b/mlir/test/Target/LLVMIR/nvvm/convert_fp4x2.mlir
new file mode 100644
index 0000000000000..e43dea4065c08
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/nvvm/convert_fp4x2.mlir
@@ -0,0 +1,14 @@
+// RUN: mlir-translate -mlir-to-llvmir %s | FileCheck %s
+
+// -----
+
+// CHECK-LABEL: @convert_f4x2_to_f16x2
+llvm.func @convert_f4x2_to_f16x2(%src : i8) {
+  // CHECK: %[[res1:.*]] = zext i8 %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e2m1x2.to.f16x2.rn(i16 %[[res1]])
+  %res1 = nvvm.convert.f4x2.to.f16x2 %src : i8 (f4E2M1FN)-> vector<2xf16>
+  // CHECK: %[[res2:.*]] = zext i8 %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e2m1x2.to.f16x2.rn.relu(i16 %[[res2]])
+  %res2 = nvvm.convert.f4x2.to.f16x2 %src {relu = true} : i8 (f4E2M1FN)-> vector<2xf16>
+  llvm.return
+}
diff --git a/mlir/test/Target/LLVMIR/nvvm/convert_fp6x2.mlir b/mlir/test/Target/LLVMIR/nvvm/convert_fp6x2.mlir
index 99289923b58b1..61a7a48f40d54 100644
--- a/mlir/test/Target/LLVMIR/nvvm/convert_fp6x2.mlir
+++ b/mlir/test/Target/LLVMIR/nvvm/convert_fp6x2.mlir
@@ -19,3 +19,27 @@ llvm.func @convert_f32x2_to_fp6x2_vector(%srcA : f32, %srcB : f32) {
   %res2 = nvvm.convert.f32x2.to.f6x2 %srcA, %srcB : vector<2xi8> (f6E3M2FN)
   llvm.return
 }
+
+// -----
+
+// CHECK-LABEL: @convert_f6x2_to_f16x2_e2m3
+llvm.func @convert_f6x2_to_f16x2_e2m3(%src : vector<2xi8>) {
+  // CHECK: %[[res1:.*]] = bitcast <2 x i8> %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e2m3x2.to.f16x2.rn(i16 %[[res1]])
+  %res1 = nvvm.convert.f6x2.to.f16x2 %src : vector<2xi8> (f6E2M3FN)-> vector<2xf16>
+  // CHECK: %[[res2:.*]] = bitcast <2 x i8> %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e2m3x2.to.f16x2.rn.relu(i16 %[[res2]])
+  %res2 = nvvm.convert.f6x2.to.f16x2 %src {relu = true} : vector<2xi8> (f6E2M3FN)-> vector<2xf16>
+  llvm.return
+}
+
+// CHECK-LABEL: @convert_f6x2_to_f16x2_e3m2
+llvm.func @convert_f6x2_to_f16x2_e3m2(%src : vector<2xi8>) {
+  // CHECK: %[[res1:.*]] = bitcast <2 x i8> %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e3m2x2.to.f16x2.rn(i16 %[[res1]])
+  %res1 = nvvm.convert.f6x2.to.f16x2 %src : vector<2xi8> (f6E3M2FN)-> vector<2xf16>
+  // CHECK: %[[res2:.*]] = bitcast <2 x i8> %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e3m2x2.to.f16x2.rn.relu(i16 %[[res2]])
+  %res2 = nvvm.convert.f6x2.to.f16x2 %src {relu = true} : vector<2xi8> (f6E3M2FN)-> vector<2xf16>
+  llvm.return
+}
diff --git a/mlir/test/Target/LLVMIR/nvvm/convert_fp8x2.mlir b/mlir/test/Target/LLVMIR/nvvm/convert_fp8x2.mlir
index de21826445afb..4afe901bc08e9 100644
--- a/mlir/test/Target/LLVMIR/nvvm/convert_fp8x2.mlir
+++ b/mlir/test/Target/LLVMIR/nvvm/convert_fp8x2.mlir
@@ -100,3 +100,37 @@ llvm.func @convert_bf16x2_to_f8x2_vector_return(%src : vector<2xbf16>) {
   %res2 = nvvm.convert.bf16x2.to.f8x2 %src {rnd = #nvvm.fp_rnd_mode<rp>, sat = #nvvm.sat_mode<satfinite>} : vector<2xbf16> -> vector<2xi8> (f8E8M0FNU)
   llvm.return
 }
+
+// -----
+
+// CHECK-LABEL: @convert_f8x2_to_f16x2
+llvm.func @convert_f8x2_to_f16x2_e4m3(%src : vector<2xi8>) {
+  // CHECK: %[[res1:.*]] = bitcast <2 x i8> %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e4m3x2.to.f16x2.rn(i16 %[[res1]])
+  %res1 = nvvm.convert.f8x2.to.f16x2 %src : vector<2xi8> (f8E4M3FN)-> vector<2xf16>
+  // CHECK: %[[res2:.*]] = bitcast <2 x i8> %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e4m3x2.to.f16x2.rn.relu(i16 %[[res2]])
+  %res2 = nvvm.convert.f8x2.to.f16x2 %src {relu = true} : vector<2xi8> (f8E4M3FN)-> vector<2xf16>
+  llvm.return
+}
+
+// CHECK-LABEL: @convert_f8x2_to_f16x2_e5m2
+llvm.func @convert_f8x2_to_f16x2_e5m2(%src : vector<2xi8>) {
+  // CHECK: %[[res1:.*]] = bitcast <2 x i8> %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e5m2x2.to.f16x2.rn(i16 %[[res1]])
+  %res1 = nvvm.convert.f8x2.to.f16x2 %src : vector<2xi8> (f8E5M2)-> vector<2xf16>
+  // CHECK: %[[res2:.*]] = bitcast <2 x i8> %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x half> @llvm.nvvm.e5m2x2.to.f16x2.rn.relu(i16 %[[res2]])
+  %res2 = nvvm.convert.f8x2.to.f16x2 %src {relu = true} : vector<2xi8> (f8E5M2)-> vector<2xf16>
+  llvm.return
+}
+
+// -----
+
+// CHECK-LABEL: @convert_f8x2_to_bf16x2_ue8m0
+llvm.func @convert_f8x2_to_bf16x2_ue8m0(%src : vector<2xi8>) {
+  // CHECK: %[[res1:.*]] = bitcast <2 x i8> %{{.*}} to i16
+  // CHECK-NEXT: %{{.*}} = call <2 x bfloat> @llvm.nvvm.ue8m0x2.to.bf16x2(i16 %[[res1]])
+  %res1 = nvvm.convert.f8x2.to.bf16x2 %src : vector<2xi8> (f8E8M0FNU)-> vector<2xbf16>
+  llvm.return
+}
>From 75a3137bc0dc4a52ef642dc17336f5e8f2101dd8 Mon Sep 17 00:00:00 2001
From: Srinivasa Ravi <srinivasar at nvidia.com>
Date: Wed, 8 Oct 2025 06:42:13 +0000
Subject: [PATCH 2/6] add invalid test cases
---
 mlir/test/Target/LLVMIR/nvvmir-invalid.mlir | 32 +++++++++++++++++++++
 1 file changed, 32 insertions(+)
diff --git a/mlir/test/Target/LLVMIR/nvvmir-invalid.mlir b/mlir/test/Target/LLVMIR/nvvmir-invalid.mlir
index 0b3615487716d..c5f71cfeaba8b 100644
--- a/mlir/test/Target/LLVMIR/nvvmir-invalid.mlir
+++ b/mlir/test/Target/LLVMIR/nvvmir-invalid.mlir
@@ -254,6 +254,38 @@ llvm.func @nvvm_cvt_f32x2_to_f6x2_invalid_type(%a : f32, %b : f32) {
 
 // -----
 
+llvm.func @nvvm_cvt_f8x2_to_f16x2_invalid_type(%src : vector<2xi8>) {
+  // expected-error @below {{Only 'f8E4M3FN' and 'f8E5M2' types are supported for conversions from f8x2 to f16x2.}}
+  %res = nvvm.convert.f8x2.to.f16x2 %src : vector<2xi8> (f8E4M3) -> vector<2xf16>
+  llvm.return
+}
+
+// -----
+
+llvm.func @nvvm_cvt_f8x2_to_bf16x2_invalid_type(%src : vector<2xi8>) {
+  // expected-error @below {{Only 'f8E8M0FNU' type is supported for conversions from f8x2 to bf16x2.}}
+  %res = nvvm.convert.f8x2.to.bf16x2 %src : vector<2xi8> (f8E4M3FN) -> vector<2xbf16>
+  llvm.return
+}
+
+// -----
+
+llvm.func @nvvm_cvt_f6x2_to_f16x2_invalid_type(%src : vector<2xi8>) {
+  // expected-error @below {{Only 'f6E2M3FN' and 'f6E3M2FN' types are supported for conversions from f6x2 to f16x2.}}
+  %res = nvvm.convert.f6x2.to.f16x2 %src : vector<2xi8> (f8E4M3FN) -> vector<2xf16>
+  llvm.return
+}
+
+// -----
+
+llvm.func @nvvm_cvt_f4x2_to_f16x2_invalid_type(%src : i8) {
+  // expected-error @below {{Only 'f4E2M1FN' type is supported for conversions from f4x2 to f16x2.}}
+  %res = nvvm.convert.f4x2.to.f16x2 %src : i8 (f6E2M3FN) -> vector<2xf16>
+  llvm.return
+}
+
+// -----
+
 llvm.func @nvvm_prefetch_L1_with_evict_priority(%global_ptr: !llvm.ptr<1>) {
   // expected-error @below {{cache eviction priority supported only for cache level L2}}
   nvvm.prefetch level = L1, evict_priority = evict_last, %global_ptr : !llvm.ptr<1>
>From 36d41ee036f7c3c8717bc52e372c80d91dd5f0b8 Mon Sep 17 00:00:00 2001
From: Srinivasa Ravi <srinivasar at nvidia.com>
Date: Wed, 8 Oct 2025 06:44:25 +0000
Subject: [PATCH 3/6] fix formatting
---
 mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td | 8 +++-----
 mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp  | 2 +-
 2 files changed, 4 insertions(+), 6 deletions(-)
diff --git a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
index 5020af3992173..e6cfa24ccc3bb 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
@@ -1843,7 +1843,7 @@ class NVVM_ConvertF8x2ToFP16x2Op_Base <string dstType>
     The `relu` attribute, when set, lowers to the '.relu' variant of
     the cvt instruction.
     
-    For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
+    [For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
   }];
   let results = (outs VectorOfLengthAndType<[2], [!cast<Type>(dstType)]>:$dst);
   let arguments = !if(!eq(dstType, "F16"),
@@ -1867,11 +1867,9 @@ class NVVM_ConvertF8x2ToFP16x2Op_Base <string dstType>
     $dst = createIntrinsicCall(builder, intId, args);
   }];
 }
-
 def NVVM_ConvertF8x2ToF16x2Op : NVVM_ConvertF8x2ToFP16x2Op_Base<"F16">;
 def NVVM_ConvertF8x2ToBF16x2Op : NVVM_ConvertF8x2ToFP16x2Op_Base<"BF16">;
 
-
 def NVVM_ConvertF6x2ToF16x2Op : NVVM_Op<"convert.f6x2.to.f16x2"> {
   let summary = "Convert a pair of f6 inputs to f16x2";
   let description = [{
@@ -1882,7 +1880,7 @@ def NVVM_ConvertF6x2ToF16x2Op : NVVM_Op<"convert.f6x2.to.f16x2"> {
     The `relu` attribute, when set, lowers to the '.relu' variant of
     the cvt instruction.
 
-    For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
+    [For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
   }];
   let results = (outs VectorOfLengthAndType<[2], [F16]>:$dst);
   let arguments = (ins VectorOfLengthAndType<[2], [I8]>:$src,
@@ -1917,7 +1915,7 @@ def NVVM_ConvertF4x2ToF16x2Op : NVVM_Op<"convert.f4x2.to.f16x2"> {
     The `relu` attribute, when set, lowers to the '.relu' variant of
     the cvt instruction.
 
-    For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
+    [For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
   }];
   let results = (outs VectorOfLengthAndType<[2], [F16]>:$dst);
   let arguments = (ins I8:$src,
diff --git a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
index bd38db52179a6..de7b9c31f7623 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
@@ -2154,7 +2154,7 @@ ConvertBF16x2ToF8x2Op::getIntrinsicID(NVVM::FPRoundingMode rnd,
 NVVM::IDArgPair ConvertF8x2ToF16x2Op::getIntrinsicIDAndArgs(
     Operation &op, LLVM::ModuleTranslation &mt, llvm::IRBuilderBase &builder) {
   auto curOp = cast<NVVM::ConvertF8x2ToF16x2Op>(op);
-  
+
   bool hasRelu = curOp.getRelu();
 
   llvm::Intrinsic::ID intId =
>From 23afb336e4a66bf49116ff67e03a6b0451bed7cf Mon Sep 17 00:00:00 2001
From: Srinivasa Ravi <srinivasar at nvidia.com>
Date: Wed, 8 Oct 2025 08:48:10 +0000
Subject: [PATCH 4/6] fix formatting
---
 mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
index de7b9c31f7623..229a1f3a4ad66 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/NVVMDialect.cpp
@@ -2160,14 +2160,12 @@ NVVM::IDArgPair ConvertF8x2ToF16x2Op::getIntrinsicIDAndArgs(
   llvm::Intrinsic::ID intId =
       llvm::TypeSwitch<mlir::Type, llvm::Intrinsic::ID>(curOp.getSrcType())
           .Case<Float8E4M3FNType>([&](Float8E4M3FNType type) {
-            return hasRelu
-                       ? llvm::Intrinsic::nvvm_e4m3x2_to_f16x2_rn_relu
-                       : llvm::Intrinsic::nvvm_e4m3x2_to_f16x2_rn;
+            return hasRelu ? llvm::Intrinsic::nvvm_e4m3x2_to_f16x2_rn_relu
+                           : llvm::Intrinsic::nvvm_e4m3x2_to_f16x2_rn;
           })
           .Case<Float8E5M2Type>([&](Float8E5M2Type type) {
-            return hasRelu
-                       ? llvm::Intrinsic::nvvm_e5m2x2_to_f16x2_rn_relu
-                       : llvm::Intrinsic::nvvm_e5m2x2_to_f16x2_rn;
+            return hasRelu ? llvm::Intrinsic::nvvm_e5m2x2_to_f16x2_rn_relu
+                           : llvm::Intrinsic::nvvm_e5m2x2_to_f16x2_rn;
           })
           .Default([](mlir::Type type) {
             llvm_unreachable("Invalid type for ConvertF8x2ToF16x2Op");
>From 41e2da8173dec1d64e03bbb7d30fe1bb35b94018 Mon Sep 17 00:00:00 2001
From: Srinivasa Ravi <srinivasar at nvidia.com>
Date: Wed, 8 Oct 2025 10:27:02 +0000
Subject: [PATCH 5/6] refactor tablegen
---
 mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td | 100 +++++---------------
 1 file changed, 22 insertions(+), 78 deletions(-)
diff --git a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
index e6cfa24ccc3bb..ed1308fba5578 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
@@ -1832,25 +1832,28 @@ def NVVM_ConvertBF16x2ToF8x2Op : NVVM_Op<"convert.bf16x2.to.f8x2"> {
   }];
 }
 
-class NVVM_ConvertF8x2ToFP16x2Op_Base <string dstType>
-: NVVM_Op<"convert.f8x2.to." # !tolower(dstType) # "x2"> {
-  let summary = "Convert a pair of f8 inputs to " # !tolower(dstType) # "x2";
+class NVVM_ConvertToFP16x2Op_Base <string srcType, Type srcArgType, string dstType>
+: NVVM_Op<"convert." # srcType # "x2.to." # !tolower(dstType) # "x2"> {
+  let summary = "Convert a pair of " # srcType # " inputs to " # !tolower(dstType) # "x2";
   let description = [{
-    This Op converts the given f8 inputs in a i8x2 vector to }] # !tolower(dstType) # [{.
+    This Op converts the given }] # srcType # [{ inputs in a }] #
+    !if(!eq(srcType, "f4"), "packed i8", "i8x2 vector") # [{ to }] #
+    !tolower(dstType) # [{.
 
     The result `dst` is represented as a vector of }] # !tolower(dstType) # [{ elements.
-
-    The `relu` attribute, when set, lowers to the '.relu' variant of
-    the cvt instruction.
+    }] #
+    !if(!eq(dstType, "F16"),
+    [{The `relu` attribute, when set, lowers to the '.relu' variant of 
+    the cvt instruction."}], "") # [{
     
     [For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
   }];
   let results = (outs VectorOfLengthAndType<[2], [!cast<Type>(dstType)]>:$dst);
   let arguments = !if(!eq(dstType, "F16"),
-    (ins VectorOfLengthAndType<[2], [I8]>:$src,
+    (ins srcArgType:$src,
          DefaultValuedAttr<BoolAttr, "false">:$relu,
          TypeAttr:$srcType),
-    (ins VectorOfLengthAndType<[2], [I8]>:$src,
+    (ins srcArgType:$src,
          TypeAttr:$srcType));
   let assemblyFormat = "$src attr-dict `:` type($src) `(` $srcType `)` `->` type($dst)";
   let hasVerifier = 1;
@@ -1863,79 +1866,20 @@ class NVVM_ConvertF8x2ToFP16x2Op_Base <string dstType>
 
   string llvmBuilder = [{
     auto [intId, args] =
-    NVVM::ConvertF8x2To}] # dstType # [{x2Op::getIntrinsicIDAndArgs(*op, moduleTranslation, builder);
-    $dst = createIntrinsicCall(builder, intId, args);
-  }];
-}
-def NVVM_ConvertF8x2ToF16x2Op : NVVM_ConvertF8x2ToFP16x2Op_Base<"F16">;
-def NVVM_ConvertF8x2ToBF16x2Op : NVVM_ConvertF8x2ToFP16x2Op_Base<"BF16">;
-
-def NVVM_ConvertF6x2ToF16x2Op : NVVM_Op<"convert.f6x2.to.f16x2"> {
-  let summary = "Convert a pair of f6 inputs to f16x2";
-  let description = [{
-    This Op converts the given f6 inputs in a i8x2 vector to f16x2.
-
-    The result `dst` is represented as a vector of f16 elements.
-    
-    The `relu` attribute, when set, lowers to the '.relu' variant of
-    the cvt instruction.
-
-    [For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
-  }];
-  let results = (outs VectorOfLengthAndType<[2], [F16]>:$dst);
-  let arguments = (ins VectorOfLengthAndType<[2], [I8]>:$src,
-         DefaultValuedAttr<BoolAttr, "false">:$relu,
-         TypeAttr:$srcType);
-  let assemblyFormat = "$src attr-dict `:` type($src) `(` $srcType `)` `->` type($dst)";
-  let hasVerifier = 1;
-
-  let extraClassDeclaration = [{
-    static IDArgPair
-    getIntrinsicIDAndArgs(Operation &op, LLVM::ModuleTranslation &mt, 
-                          llvm::IRBuilderBase &builder);
-  }];
-
-  string llvmBuilder = [{
-    auto [intId, args] =
-    NVVM::ConvertF6x2ToF16x2Op::getIntrinsicIDAndArgs(*op, moduleTranslation, builder);
+    NVVM::Convert}] # !toupper(srcType) # [{x2To}] # dstType # 
+      [{x2Op::getIntrinsicIDAndArgs(*op, moduleTranslation, builder);
     $dst = createIntrinsicCall(builder, intId, args);
   }];
 }
 
-def NVVM_ConvertF4x2ToF16x2Op : NVVM_Op<"convert.f4x2.to.f16x2"> {
-  let summary = "Convert a pair of f4 inputs to f16x2";
-  let description = [{
-    This Op converts the given f4 inputs packed in an i8 to f16x2.
-
-    The result `dst` is represented as a vector of f16 elements. The value 
-    converted from the lower 4 bits of `src` is stored in the first element of 
-    `dst` and the value converted from the upper 4 bits of `src` is stored in 
-    the second element of `dst`.
-
-    The `relu` attribute, when set, lowers to the '.relu' variant of
-    the cvt instruction.
-
-    [For more information, see PTX ISA](https://docs.nvidia.com/cuda/parallel-thread-execution/index.html#data-movement-and-conversion-instructions-cvt)
-  }];
-  let results = (outs VectorOfLengthAndType<[2], [F16]>:$dst);
-  let arguments = (ins I8:$src,
-         DefaultValuedAttr<BoolAttr, "false">:$relu,
-         TypeAttr:$srcType);
-  let assemblyFormat = "$src attr-dict `:` type($src) `(` $srcType `)` `->` type($dst)";
-  let hasVerifier = 1;
-
-  let extraClassDeclaration = [{
-    static IDArgPair
-    getIntrinsicIDAndArgs(Operation &op, LLVM::ModuleTranslation &mt, 
-                          llvm::IRBuilderBase &builder);
-  }];
-
-  string llvmBuilder = [{
-    auto [intId, args] =
-    NVVM::ConvertF4x2ToF16x2Op::getIntrinsicIDAndArgs(*op, moduleTranslation, builder);
-    $dst = createIntrinsicCall(builder, intId, args);
-  }];
-}
+def NVVM_ConvertF8x2ToF16x2Op :
+  NVVM_ConvertToFP16x2Op_Base<"f8", VectorOfLengthAndType<[2], [I8]>, "F16">;
+def NVVM_ConvertF8x2ToBF16x2Op :
+  NVVM_ConvertToFP16x2Op_Base<"f8", VectorOfLengthAndType<[2], [I8]>, "BF16">;
+def NVVM_ConvertF6x2ToF16x2Op :
+  NVVM_ConvertToFP16x2Op_Base<"f6", VectorOfLengthAndType<[2], [I8]>, "F16">;
+def NVVM_ConvertF4x2ToF16x2Op :
+  NVVM_ConvertToFP16x2Op_Base<"f4", I8, "F16">;
 
 //===----------------------------------------------------------------------===//
 // NVVM MMA Ops
>From a349a4f0da142436f176bc4fb89615822ddeef04 Mon Sep 17 00:00:00 2001
From: Srinivasa Ravi <srinivasar at nvidia.com>
Date: Fri, 10 Oct 2025 06:44:53 +0000
Subject: [PATCH 6/6] match argument cases
---
 mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
index ed1308fba5578..0287a20e7ed10 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/NVVMOps.td
@@ -1833,11 +1833,11 @@ def NVVM_ConvertBF16x2ToF8x2Op : NVVM_Op<"convert.bf16x2.to.f8x2"> {
 }
 
 class NVVM_ConvertToFP16x2Op_Base <string srcType, Type srcArgType, string dstType>
-: NVVM_Op<"convert." # srcType # "x2.to." # !tolower(dstType) # "x2"> {
-  let summary = "Convert a pair of " # srcType # " inputs to " # !tolower(dstType) # "x2";
+: NVVM_Op<"convert." # !tolower(srcType) # "x2.to." # !tolower(dstType) # "x2"> {
+  let summary = "Convert a pair of " # !tolower(srcType) # " inputs to " # !tolower(dstType) # "x2";
   let description = [{
-    This Op converts the given }] # srcType # [{ inputs in a }] #
-    !if(!eq(srcType, "f4"), "packed i8", "i8x2 vector") # [{ to }] #
+    This Op converts the given }] # !tolower(srcType) # [{ inputs in a }] #
+    !if(!eq(srcType, "F4"), "packed i8", "i8x2 vector") # [{ to }] #
     !tolower(dstType) # [{.
 
     The result `dst` is represented as a vector of }] # !tolower(dstType) # [{ elements.
@@ -1866,20 +1866,20 @@ class NVVM_ConvertToFP16x2Op_Base <string srcType, Type srcArgType, string dstTy
 
   string llvmBuilder = [{
     auto [intId, args] =
-    NVVM::Convert}] # !toupper(srcType) # [{x2To}] # dstType # 
+    NVVM::Convert}] # srcType # [{x2To}] # dstType # 
       [{x2Op::getIntrinsicIDAndArgs(*op, moduleTranslation, builder);
     $dst = createIntrinsicCall(builder, intId, args);
   }];
 }
 
 def NVVM_ConvertF8x2ToF16x2Op :
-  NVVM_ConvertToFP16x2Op_Base<"f8", VectorOfLengthAndType<[2], [I8]>, "F16">;
+  NVVM_ConvertToFP16x2Op_Base<"F8", VectorOfLengthAndType<[2], [I8]>, "F16">;
 def NVVM_ConvertF8x2ToBF16x2Op :
-  NVVM_ConvertToFP16x2Op_Base<"f8", VectorOfLengthAndType<[2], [I8]>, "BF16">;
+  NVVM_ConvertToFP16x2Op_Base<"F8", VectorOfLengthAndType<[2], [I8]>, "BF16">;
 def NVVM_ConvertF6x2ToF16x2Op :
-  NVVM_ConvertToFP16x2Op_Base<"f6", VectorOfLengthAndType<[2], [I8]>, "F16">;
+  NVVM_ConvertToFP16x2Op_Base<"F6", VectorOfLengthAndType<[2], [I8]>, "F16">;
 def NVVM_ConvertF4x2ToF16x2Op :
-  NVVM_ConvertToFP16x2Op_Base<"f4", I8, "F16">;
+  NVVM_ConvertToFP16x2Op_Base<"F4", I8, "F16">;
 
 //===----------------------------------------------------------------------===//
 // NVVM MMA Ops
    
    
More information about the Mlir-commits
mailing list