[Mlir-commits] [mlir] [mlir][SPIR-V] Add SPIRVToLLVM conversions for GL.FMix and CL.mix (PR #206935)

[Arseniy Obolenskiy]

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@@ -1584,6 +1584,55 @@ class FractPattern : public SPIRVToLLVMConversion<spirv::GLFractOp> {
   }
 };
 
+/// Converts `spirv.GL.FMix` to `x * (1 - a) + y * a` as specified by
+/// GL.std.450.
+class GLFMixPattern : public SPIRVToLLVMConversion<spirv::GLFMixOp> {
+public:
+  using SPIRVToLLVMConversion<spirv::GLFMixOp>::SPIRVToLLVMConversion;
+
+  LogicalResult
+  matchAndRewrite(spirv::GLFMixOp op, OpAdaptor adaptor,
+                  ConversionPatternRewriter &rewriter) const override {
+    Type dstType = getTypeConverter()->convertType(op.getType());
+    if (!dstType)
+      return rewriter.notifyMatchFailure(op, "type conversion failed");
+
+    Location loc = op.getLoc();
+    Value x = adaptor.getX();
+    Value y = adaptor.getY();
+    Value a = adaptor.getA();
+    Value one = createFPConstant(loc, op.getType(), dstType, rewriter, 1.0);
+    Value oneMinusA = LLVM::FSubOp::create(rewriter, loc, dstType, one, a);
+    Value lhs = LLVM::FMulOp::create(rewriter, loc, dstType, x, oneMinusA);
+    Value rhs = LLVM::FMulOp::create(rewriter, loc, dstType, y, a);
+    rewriter.replaceOpWithNewOp<LLVM::FAddOp>(op, dstType, lhs, rhs);
+    return success();
+  }
+};
+
+/// Converts `spirv.CL.mix` to `fma(a, y - x, x)`. The OpenCL spec defines
+/// mix as `x + (y - x) * a` and explicitly permits FMA contractions.
+class CLMixPattern : public SPIRVToLLVMConversion<spirv::CLMixOp> {
+public:
+  using SPIRVToLLVMConversion<spirv::CLMixOp>::SPIRVToLLVMConversion;
+
+  LogicalResult
+  matchAndRewrite(spirv::CLMixOp op, OpAdaptor adaptor,
+                  ConversionPatternRewriter &rewriter) const override {
+    Type dstType = getTypeConverter()->convertType(op.getType());
+    if (!dstType)
+      return rewriter.notifyMatchFailure(op, "type conversion failed");
+
+    Location loc = op.getLoc();
+    Value x = adaptor.getOperands()[0];
+    Value y = adaptor.getOperands()[1];
+    Value a = adaptor.getOperands()[2];
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aobolensk wrote:

Done

https://github.com/llvm/llvm-project/pull/206935