[CIR] Implement foldder for VecExtractOp

Author: AmrDeveloper

clang/include/clang/CIR/Dialect/IR/CIROps.td

@@ -1995,6 +1995,8 @@ def VecExtractOp : CIR_Op<"vec.extract", [Pure,
   let assemblyFormat = [{
     $vec `[` $index `:` type($index) `]` attr-dict `:` qualified(type($vec))
   }];
+
+  let hasFolder = 1;
 }
 
 #endif // CLANG_CIR_DIALECT_IR_CIROPS_TD

clang/lib/CIR/Dialect/IR/CIRDialect.cpp

@@ -1395,6 +1395,26 @@ LogicalResult cir::VecCreateOp::verify() {
   return success();
 }
 
+//===----------------------------------------------------------------------===//
+// VecExtractOp
+//===----------------------------------------------------------------------===//
+
+OpFoldResult cir::VecExtractOp::fold(FoldAdaptor adaptor) {
+  const auto vectorAttr =
+      llvm::dyn_cast_if_present<cir::ConstVectorAttr>(adaptor.getVec());
+  if (!vectorAttr)
+    return {};
+
+  const auto indexAttr =
+      llvm::dyn_cast_if_present<cir::IntAttr>(adaptor.getIndex());
+  if (!indexAttr)
+    return {};
+
+  const mlir::ArrayAttr elements = vectorAttr.getElts();
+  const int64_t index = indexAttr.getSInt();
+  return elements[index];
+}
+
 //===----------------------------------------------------------------------===//
 // TableGen'd op method definitions
 //===----------------------------------------------------------------------===//

clang/lib/CIR/Dialect/Transforms/CIRCanonicalize.cpp

@@ -125,9 +125,10 @@ void CIRCanonicalizePass::runOnOperation() {
     assert(!cir::MissingFeatures::complexRealOp());
     assert(!cir::MissingFeatures::complexImagOp());
     assert(!cir::MissingFeatures::callOp());
-    // CastOp and UnaryOp are here to perform a manual `fold` in
+    // CastOp, UnaryOp and VecExtractOp are here to perform a manual `fold` in
     // applyOpPatternsGreedily.
-    if (isa<BrOp, BrCondOp, CastOp, ScopeOp, SelectOp, UnaryOp>(op))
+    if (isa<BrOp, BrCondOp, CastOp, ScopeOp, SelectOp, UnaryOp, VecExtractOp>(
+            op))
       ops.push_back(op);
   });
 

clang/test/CIR/Transforms/vector-extract-fold.cir

@@ -0,0 +1,20 @@
+// RUN: cir-opt %s -cir-canonicalize -o - | FileCheck %s
+
+!s32i = !cir.int<s, 32>
+
+module {
+  cir.func @fold_extract_vector_op_test() {
+    %init = cir.alloca !s32i, !cir.ptr<!s32i>, ["e", init]
+    %const_vec = cir.const #cir.const_vector<[#cir.int<1> : !s32i, #cir.int<2> : !s32i, #cir.int<3> : !s32i, #cir.int<4> : !s32i]> : !cir.vector<4 x !s32i>
+    %index = cir.const #cir.int<1> : !s32i
+    %ele = cir.vec.extract %const_vec[%index : !s32i] : !cir.vector<4 x !s32i>
+    cir.store %ele, %init : !s32i, !cir.ptr<!s32i>
+    cir.return
+  }
+
+  // CHECK: %[[INIT:.*]] = cir.alloca !s32i, !cir.ptr<!s32i>, ["e", init]
+  // CHECK: %[[VALUE:.*]] = cir.const #cir.int<2> : !s32i
+  // CHECK: cir.store %[[VALUE]], %[[INIT]] : !s32i, !cir.ptr<!s32i>
+}
+
+