[Mlir-commits] [mlir] [MLIR][ROCDL] Add conversion for gpu.subgroup_id to ROCDL (PR #136405)

[Krzysztof Drewniak]

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@@ -190,6 +201,33 @@ struct GPUShuffleOpLowering : public ConvertOpToLLVMPattern<gpu::ShuffleOp> {
   }
 };
 
+struct GPUSubgroupIdOpToROCDL final
+    : ConvertOpToLLVMPattern<gpu::SubgroupIdOp> {
+  using ConvertOpToLLVMPattern::ConvertOpToLLVMPattern;
+
+  GPUSubgroupIdOpToROCDL(const LLVMTypeConverter &converter,
+                         const mlir::amdgpu::Chipset &chipset)
+      : ConvertOpToLLVMPattern(converter), chipset(chipset) {}
+
+  const mlir::amdgpu::Chipset chipset;
+
+  LogicalResult
+  matchAndRewrite(gpu::SubgroupIdOp op, gpu::SubgroupIdOp::Adaptor adaptor,
+                  ConversionPatternRewriter &rewriter) const override {
+    if (chipset.majorVersion < 10) {
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krzysz00 wrote:

There's a valid implementation: `workitem_id.x + workitem_dim.x * (workitem_id.y + workitem_dim.y * workitem_id.z)) / 64`, with all those adds and muls being `nuw` and `nsw`

https://github.com/llvm/llvm-project/pull/136405