[Mlir-commits] [mlir] [mlir][SPIR-V] Add SPIRVToLLVM conversion for VectorTimesScalar (PR #206949)

[Arseniy Obolenskiy]

https://github.com/aobolensk created https://github.com/llvm/llvm-project/pull/206949

None

>From 86c221950fd16910955f66c6be5c59c7f76b99f0 Mon Sep 17 00:00:00 2001
From: Arseniy Obolenskiy <arseniy.obolenskiy at amd.com>
Date: Wed, 1 Jul 2026 13:10:12 +0200
Subject: [PATCH] [mlir][SPIR-V] Add SPIRVToLLVM conversion for
 VectorTimesScalar

---
 .../Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp    | 26 +++++++++++++++++++
 .../SPIRVToLLVM/arithmetic-ops-to-llvm.mlir   | 15 +++++++++++
 2 files changed, 41 insertions(+)

diff --git a/mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp b/mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp
index c43415b27b1b3..23007a58713bd 100644
--- a/mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp
+++ b/mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp
@@ -921,6 +921,31 @@ class InverseSqrtPattern
   }
 };
 
+/// Converts `spirv.VectorTimesScalar` to a broadcast of the scalar followed by
+/// an `llvm.fmul`.
+class VectorTimesScalarPattern
+    : public SPIRVToLLVMConversion<spirv::VectorTimesScalarOp> {
+public:
+  using SPIRVToLLVMConversion<
+      spirv::VectorTimesScalarOp>::SPIRVToLLVMConversion;
+
+  LogicalResult
+  matchAndRewrite(spirv::VectorTimesScalarOp op, OpAdaptor adaptor,
+                  ConversionPatternRewriter &rewriter) const override {
+    auto srcType = op.getType();
+    auto dstType = getTypeConverter()->convertType(srcType);
+    if (!dstType)
+      return rewriter.notifyMatchFailure(op, "type conversion failed");
+
+    unsigned numElements = op.getVector().getType().getNumElements();
+    Value broadcasted = broadcast(op.getLoc(), adaptor.getScalar(), numElements,
+                                  *getTypeConverter(), rewriter);
+    rewriter.replaceOpWithNewOp<LLVM::FMulOp>(op, dstType, adaptor.getVector(),
+                                              broadcasted);
+    return success();
+  }
+};
+
 /// Converts `spirv.Load` and `spirv.Store` to LLVM dialect.
 template <typename SPIRVOp>
 class LoadStorePattern : public SPIRVToLLVMConversion<SPIRVOp> {
@@ -1825,6 +1850,7 @@ void mlir::populateSPIRVToLLVMConversionPatterns(
       DirectConversionPattern<spirv::SRemOp, LLVM::SRemOp>,
       DirectConversionPattern<spirv::UDivOp, LLVM::UDivOp>,
       DirectConversionPattern<spirv::UModOp, LLVM::URemOp>,
+      VectorTimesScalarPattern,
 
       // Bitwise ops
       BitFieldInsertPattern, BitFieldUExtractPattern, BitFieldSExtractPattern,
diff --git a/mlir/test/Conversion/SPIRVToLLVM/arithmetic-ops-to-llvm.mlir b/mlir/test/Conversion/SPIRVToLLVM/arithmetic-ops-to-llvm.mlir
index dbbf8610afb4d..0739f377c008f 100644
--- a/mlir/test/Conversion/SPIRVToLLVM/arithmetic-ops-to-llvm.mlir
+++ b/mlir/test/Conversion/SPIRVToLLVM/arithmetic-ops-to-llvm.mlir
@@ -233,3 +233,18 @@ spirv.func @srem_vector(%arg0: vector<4xi32>, %arg1: vector<4xi32>) "None" {
   %0 = spirv.SRem %arg0, %arg1 : vector<4xi32>
   spirv.Return
 }
+
+//===----------------------------------------------------------------------===//
+// spirv.VectorTimesScalar
+//===----------------------------------------------------------------------===//
+
+// CHECK-LABEL: @vector_times_scalar
+spirv.func @vector_times_scalar(%vector: vector<4xf32>, %scalar: f32) "None" {
+  // CHECK: %[[UNDEF:.*]] = llvm.mlir.poison : vector<4xf32>
+  // CHECK: llvm.insertelement %{{.*}}, %[[UNDEF]]
+  // CHECK-COUNT-2: llvm.insertelement
+  // CHECK: %[[BCAST:.*]] = llvm.insertelement
+  // CHECK: llvm.fmul %{{.*}}, %[[BCAST]] : vector<4xf32>
+  %0 = spirv.VectorTimesScalar %vector, %scalar : (vector<4xf32>, f32) -> vector<4xf32>
+  spirv.Return
+}