[mlir][vector] Add emulation patterns for vector masked load/store (#74834)

In this patch, it will convert

```
vector.maskedload %base[%idx_0, %idx_1], %mask, %pass_thru
```

to

```
%ivalue = %pass_thru
%m = vector.extract %mask[0]
%result0 = scf.if %m {
  %v = memref.load %base[%idx_0, %idx_1]
  %combined = vector.insert %v, %ivalue[0]
  scf.yield %combined
} else {
  scf.yield %ivalue
}
%m = vector.extract %mask[1]
%result1 = scf.if %m {
  %v = memref.load %base[%idx_0, %idx_1 + 1]
  %combined = vector.insert %v, %result0[1]
  scf.yield %combined
} else {
  scf.yield %result0
}
...
```

It will convert

```
vector.maskedstore %base[%idx_0, %idx_1], %mask, %value
```

to

```
%m = vector.extract %mask[0]
scf.if %m {
  %extracted = vector.extract %value[0]
  memref.store %extracted, %base[%idx_0, %idx_1]
}
%m = vector.extract %mask[1]
scf.if %m {
  %extracted = vector.extract %value[1]
  memref.store %extracted, %base[%idx_0, %idx_1 + 1]
}
...
```

1 files changed, 27 insertions, 0 deletions

diff --git a/mlir/test/lib/Dialect/Vector/TestVectorTransforms.cpp b/mlir/test/lib/Dialect/Vector/TestVectorTransforms.cpp
index a643343e9342..03ddebe82344 100644
--- a/mlir/test/lib/Dialect/Vector/TestVectorTransforms.cpp
+++ b/mlir/test/lib/Dialect/Vector/TestVectorTransforms.cpp
@@ -777,6 +777,31 @@ struct TestFoldArithExtensionIntoVectorContractPatterns
     (void)applyPatternsAndFoldGreedily(getOperation(), std::move(patterns));
   }
 };
+
+struct TestVectorEmulateMaskedLoadStore final
+    : public PassWrapper<TestVectorEmulateMaskedLoadStore,
+                         OperationPass<func::FuncOp>> {
+  MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(TestVectorEmulateMaskedLoadStore)
+
+  StringRef getArgument() const override {
+    return "test-vector-emulate-masked-load-store";
+  }
+  StringRef getDescription() const override {
+    return "Test patterns that emulate the maskedload/maskedstore op by "
+           " memref.load/store and scf.if";
+  }
+  void getDependentDialects(DialectRegistry &registry) const override {
+    registry
+        .insert<arith::ArithDialect, func::FuncDialect, memref::MemRefDialect,
+                scf::SCFDialect, vector::VectorDialect>();
+  }
+
+  void runOnOperation() override {
+    RewritePatternSet patterns(&getContext());
+    populateVectorMaskedLoadStoreEmulationPatterns(patterns);
+    (void)applyPatternsAndFoldGreedily(getOperation(), std::move(patterns));
+  }
+};
 } // namespace
 
 namespace mlir {
@@ -817,6 +842,8 @@ void registerTestVectorLowerings() {
   PassRegistration<TestVectorGatherLowering>();
 
   PassRegistration<TestFoldArithExtensionIntoVectorContractPatterns>();
+
+  PassRegistration<TestVectorEmulateMaskedLoadStore>();
 }
 } // namespace test
 } // namespace mlir