[Mlir-commits] [mlir] dc8ee15 - [mlir][SPIR-V] Add SPIRVToLLVM conversion for SNegate (#206950)

[llvmlistbot at llvm.org]

Author: Arseniy Obolenskiy
Date: 2026-07-13T11:44:29+02:00
New Revision: dc8ee15f2bbc5b18316f071c5ae746bd95609ade

URL: https://github.com/llvm/llvm-project/commit/dc8ee15f2bbc5b18316f071c5ae746bd95609ade
DIFF: https://github.com/llvm/llvm-project/commit/dc8ee15f2bbc5b18316f071c5ae746bd95609ade.diff

LOG: [mlir][SPIR-V] Add SPIRVToLLVM conversion for SNegate (#206950)

Added: 
    

Modified: 
    mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp
    mlir/test/Conversion/SPIRVToLLVM/arithmetic-ops-to-llvm.mlir

Removed: 
    


################################################################################
diff  --git a/mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp b/mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp
index 0822c44c10f1d..f8c4405157f94 100644
--- a/mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp
+++ b/mlir/lib/Conversion/SPIRVToLLVM/SPIRVToLLVM.cpp
@@ -80,27 +80,25 @@ static unsigned getLLVMTypeBitWidth(Type type) {
   return cast<IntegerType>(type).getWidth();
 }
 
-/// Creates `IntegerAttribute` with all bits set for given type
-static IntegerAttr minusOneIntegerAttribute(Type type, Builder builder) {
-  if (auto vecType = dyn_cast<VectorType>(type)) {
-    auto integerType = cast<IntegerType>(vecType.getElementType());
-    return builder.getIntegerAttr(integerType, -1);
-  }
-  auto integerType = cast<IntegerType>(type);
-  return builder.getIntegerAttr(integerType, -1);
+/// Creates `llvm.mlir.constant` with a scalar or vector integer value,
+/// broadcasting `scalarAttr` across the vector if `srcType` is a vector.
+static Value createIntegerConstant(Location loc, Type srcType, Type dstType,
+                                   PatternRewriter &rewriter,
+                                   IntegerAttr scalarAttr) {
+  if (auto vecType = dyn_cast<VectorType>(srcType))
+    return LLVM::ConstantOp::create(
+        rewriter, loc, dstType, SplatElementsAttr::get(vecType, scalarAttr));
+  return LLVM::ConstantOp::create(rewriter, loc, dstType, scalarAttr);
 }
 
 /// Creates `llvm.mlir.constant` with all bits set for the given type.
 static Value createConstantAllBitsSet(Location loc, Type srcType, Type dstType,
                                       PatternRewriter &rewriter) {
-  if (isa<VectorType>(srcType)) {
-    return LLVM::ConstantOp::create(
-        rewriter, loc, dstType,
-        SplatElementsAttr::get(cast<ShapedType>(srcType),
-                               minusOneIntegerAttribute(srcType, rewriter)));
-  }
-  return LLVM::ConstantOp::create(rewriter, loc, dstType,
-                                  minusOneIntegerAttribute(srcType, rewriter));
+  auto integerType = cast<IntegerType>(
+      isa<VectorType>(srcType) ? cast<VectorType>(srcType).getElementType()
+                               : srcType);
+  return createIntegerConstant(loc, srcType, dstType, rewriter,
+                               rewriter.getIntegerAttr(integerType, -1));
 }
 
 /// Creates `llvm.mlir.constant` with a floating-point scalar or vector value.
@@ -921,6 +919,30 @@ class InverseSqrtPattern
   }
 };
 
+/// Converts `spirv.SNegate` to `0 - x`.
+class SNegatePattern : public SPIRVToLLVMConversion<spirv::SNegateOp> {
+public:
+  using SPIRVToLLVMConversion<spirv::SNegateOp>::SPIRVToLLVMConversion;
+
+  LogicalResult
+  matchAndRewrite(spirv::SNegateOp op, OpAdaptor adaptor,
+                  ConversionPatternRewriter &rewriter) const override {
+    Type srcType = op.getType();
+    Type dstType = getTypeConverter()->convertType(srcType);
+    if (!dstType)
+      return rewriter.notifyMatchFailure(op, "type conversion failed");
+
+    Location loc = op.getLoc();
+    IntegerAttr zeroAttr = rewriter.getIntegerAttr(
+        cast<IntegerType>(getElementTypeOrSelf(srcType)), 0);
+    Value zero =
+        createIntegerConstant(loc, srcType, dstType, rewriter, zeroAttr);
+    rewriter.replaceOpWithNewOp<LLVM::SubOp>(op, dstType, zero,
+                                             adaptor.getOperand());
+    return success();
+  }
+};
+
 /// Converts the GLSL clamp ops (FClamp, SClamp, UClamp) into a nested
 /// min/max sequence, following the op semantics `min(max(x, minVal), maxVal)`.
 template <typename SPIRVOp, typename LLVMMinOp, typename LLVMMaxOp>
@@ -995,13 +1017,7 @@ class NotPattern : public SPIRVToLLVMConversion<SPIRVOp> {
       return rewriter.notifyMatchFailure(notOp, "type conversion failed");
 
     Location loc = notOp.getLoc();
-    IntegerAttr minusOne = minusOneIntegerAttribute(srcType, rewriter);
-    auto mask =
-        isa<VectorType>(srcType)
-            ? LLVM::ConstantOp::create(
-                  rewriter, loc, dstType,
-                  SplatElementsAttr::get(cast<VectorType>(srcType), minusOne))
-            : LLVM::ConstantOp::create(rewriter, loc, dstType, minusOne);
+    Value mask = createConstantAllBitsSet(loc, srcType, dstType, rewriter);
     rewriter.template replaceOpWithNewOp<LLVM::XOrOp>(notOp, dstType,
                                                       notOp.getOperand(), mask);
     return success();
@@ -1957,7 +1973,7 @@ void mlir::populateSPIRVToLLVMConversionPatterns(
       DirectConversionPattern<spirv::SDivOp, LLVM::SDivOp>,
       DirectConversionPattern<spirv::SRemOp, LLVM::SRemOp>,
       DirectConversionPattern<spirv::UDivOp, LLVM::UDivOp>,
-      DirectConversionPattern<spirv::UModOp, LLVM::URemOp>,
+      DirectConversionPattern<spirv::UModOp, LLVM::URemOp>, SNegatePattern,
 
       // 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..ee9c06fbb10e1 100644
--- a/mlir/test/Conversion/SPIRVToLLVM/arithmetic-ops-to-llvm.mlir
+++ b/mlir/test/Conversion/SPIRVToLLVM/arithmetic-ops-to-llvm.mlir
@@ -233,3 +233,23 @@ spirv.func @srem_vector(%arg0: vector<4xi32>, %arg1: vector<4xi32>) "None" {
   %0 = spirv.SRem %arg0, %arg1 : vector<4xi32>
   spirv.Return
 }
+
+//===----------------------------------------------------------------------===//
+// spirv.SNegate
+//===----------------------------------------------------------------------===//
+
+// CHECK-LABEL: @snegate_scalar
+spirv.func @snegate_scalar(%arg0: i32) "None" {
+  // CHECK: %[[ZERO:.*]] = llvm.mlir.constant(0 : i32) : i32
+  // CHECK: llvm.sub %[[ZERO]], %{{.*}} : i32
+  %0 = spirv.SNegate %arg0 : i32
+  spirv.Return
+}
+
+// CHECK-LABEL: @snegate_vector
+spirv.func @snegate_vector(%arg0: vector<4xi32>) "None" {
+  // CHECK: %[[ZERO:.*]] = llvm.mlir.constant(dense<0> : vector<4xi32>) : vector<4xi32>
+  // CHECK: llvm.sub %[[ZERO]], %{{.*}} : vector<4xi32>
+  %0 = spirv.SNegate %arg0 : vector<4xi32>
+  spirv.Return
+}