[Mlir-commits] [mlir] [mlir][SPIR-V] Add SPIRVToLLVM conversions for FMod and SMod (PR #206933)

[Igor Wodiany]

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@@ -1032,6 +1032,83 @@ class ClampPattern : public SPIRVToLLVMConversion<SPIRVOp> {
   }
 };
 
+/// Converts `spirv.FMod` to `x - y * floor(x / y)`. The SPIR-V op requires the
+/// result to take the sign of the divisor, whereas `llvm.frem` keeps the sign
+/// of the dividend, so `frem` cannot be used directly.
+class FModPattern : public SPIRVToLLVMConversion<spirv::FModOp> {
+public:
+  using SPIRVToLLVMConversion<spirv::FModOp>::SPIRVToLLVMConversion;
+
+  LogicalResult
+  matchAndRewrite(spirv::FModOp op, OpAdaptor adaptor,
+                  ConversionPatternRewriter &rewriter) const override {
+    auto dstType = getTypeConverter()->convertType(op.getType());
+    if (!dstType)
+      return rewriter.notifyMatchFailure(op, "type conversion failed");
+
+    Location loc = op.getLoc();
+    Value lhs = adaptor.getOperand1();
+    Value rhs = adaptor.getOperand2();
+    Value div = LLVM::FDivOp::create(rewriter, loc, dstType, lhs, rhs);
+    Value floored = LLVM::FFloorOp::create(rewriter, loc, dstType, div);
+    Value scaled = LLVM::FMulOp::create(rewriter, loc, dstType, rhs, floored);
+    rewriter.replaceOpWithNewOp<LLVM::FSubOp>(op, dstType, lhs, scaled);
+    return success();
+  }
+};
+
+/// Converts `spirv.SMod` to a signed remainder corrected to take the sign of
+/// the divisor. `llvm.srem` keeps the sign of the dividend, so the result is
+/// adjusted by adding the divisor when the remainder is non-zero and its sign
+/// differs from the divisor's.
+class SModPattern : public SPIRVToLLVMConversion<spirv::SModOp> {
+public:
+  using SPIRVToLLVMConversion<spirv::SModOp>::SPIRVToLLVMConversion;
+
+  LogicalResult
+  matchAndRewrite(spirv::SModOp 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");
+
+    Location loc = op.getLoc();
+    Value lhs = adaptor.getOperand1();
+    Value rhs = adaptor.getOperand2();
+    Type i1Type = rewriter.getI1Type();
+    auto vecSrcType = dyn_cast<VectorType>(srcType);
+    Type cmpType =
+        vecSrcType ? VectorType::get(vecSrcType.getShape(), i1Type) : i1Type;
+
+    Value rem = LLVM::SRemOp::create(rewriter, loc, dstType, lhs, rhs);
+    IntegerAttr zeroAttr = rewriter.getIntegerAttr(
+        cast<IntegerType>(getElementTypeOrSelf(srcType)), 0);
+    Value zero;
+    if (vecSrcType)
+      zero = LLVM::ConstantOp::create(
+          rewriter, loc, dstType, SplatElementsAttr::get(vecSrcType, zeroAttr));
+    else
+      zero = LLVM::ConstantOp::create(rewriter, loc, dstType, zeroAttr);
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IgWod wrote:

Can it use the helper as in the other PR?

https://github.com/llvm/llvm-project/pull/206933