[Mlir-commits] [mlir] [mlir][vector] Add a pattern to fuse extract(constant_mask) (PR #81057)

[Hsiangkai Wang]

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@@ -2039,6 +2039,60 @@ class ExtractOpFromCreateMask final : public OpRewritePattern<ExtractOp> {
   }
 };
 
+// Pattern to rewrite
+// ExtractOp(ConstantMaskOp) -> ConstantMaskOp
+// or
+// ExtractOp(ConstantMaskOp) -> ConstantOp
+class ExtractOpFromConstantMask final : public OpRewritePattern<ExtractOp> {
+public:
+  using OpRewritePattern::OpRewritePattern;
+
+  LogicalResult matchAndRewrite(ExtractOp extractOp,
+                                PatternRewriter &rewriter) const override {
+    auto constantMaskOp =
+        extractOp.getVector().getDefiningOp<vector::ConstantMaskOp>();
+    if (!constantMaskOp)
+      return failure();
+
+    auto maskDimSizes = constantMaskOp.getMaskDimSizes().getValue();
+    auto resultTy = extractOp.getResult().getType();
+    if (resultTy.isa<mlir::VectorType>()) {
+      auto resultVectorTy = resultTy.cast<mlir::VectorType>();
+      auto resultRank = resultVectorTy.getRank();
+      auto n = maskDimSizes.size();
+      std::vector<int64_t> indices;
+      for (size_t i = n - resultRank; i < n; i++)
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Hsiangkai wrote:

Done.

https://github.com/llvm/llvm-project/pull/81057