diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
index 6b718f923f3c..1aeb03f90b61 100644
--- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
+++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
@@ -2278,6 +2278,36 @@ class CIRBitClrsbOpLowering
   }
 };
 
+class CIRObjSizeOpLowering
+    : public mlir::OpConversionPattern<mlir::cir::ObjSizeOp> {
+public:
+  using OpConversionPattern<mlir::cir::ObjSizeOp>::OpConversionPattern;
+
+  mlir::LogicalResult
+  matchAndRewrite(mlir::cir::ObjSizeOp op, OpAdaptor adaptor,
+                  mlir::ConversionPatternRewriter &rewriter) const override {
+    auto llvmResTy = getTypeConverter()->convertType(op.getType());
+    auto loc = op->getLoc();
+
+    auto llvmIntrinNameAttr =
+        mlir::StringAttr::get(rewriter.getContext(), "llvm.objectsize");
+    mlir::cir::SizeInfoType kindInfo = op.getKind();
+    auto falseValue = rewriter.create<mlir::LLVM::ConstantOp>(
+        loc, rewriter.getI1Type(), false);
+    auto trueValue = rewriter.create<mlir::LLVM::ConstantOp>(
+        loc, rewriter.getI1Type(), true);
+
+    rewriter.replaceOpWithNewOp<mlir::LLVM::CallIntrinsicOp>(
+        op, llvmResTy, llvmIntrinNameAttr,
+        mlir::ValueRange{adaptor.getPtr(),
+                         kindInfo == mlir::cir::SizeInfoType::max ? falseValue
+                                                                  : trueValue,
+                         trueValue, op.getDynamic() ? trueValue : falseValue});
+
+    return mlir::LogicalResult::success();
+  }
+};
+
 class CIRBitClzOpLowering
     : public mlir::OpConversionPattern<mlir::cir::BitClzOp> {
 public:
@@ -3024,8 +3054,8 @@ void populateCIRToLLVMConversionPatterns(mlir::RewritePatternSet &patterns,
       CIRVectorShuffleVecLowering, CIRStackSaveLowering,
       CIRStackRestoreLowering, CIRUnreachableLowering, CIRTrapLowering,
       CIRInlineAsmOpLowering, CIRSetBitfieldLowering, CIRGetBitfieldLowering,
-      CIRPrefetchLowering, CIRIsConstantOpLowering>(converter,
-                                                    patterns.getContext());
+      CIRPrefetchLowering, CIRObjSizeOpLowering, CIRIsConstantOpLowering>(
+      converter, patterns.getContext());
 }
 
 namespace {
diff --git a/clang/test/CIR/CodeGen/pass-object-size.c b/clang/test/CIR/CodeGen/pass-object-size.c
new file mode 100644
index 000000000000..909802d522b8
--- /dev/null
+++ b/clang/test/CIR/CodeGen/pass-object-size.c
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir-enable -emit-cir %s -o %t.cir
+// RUN: FileCheck --input-file=%t.cir %s -check-prefix=CIR
+// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -fclangir-enable -emit-llvm %s -o %t.ll
+// RUN: FileCheck --input-file=%t.ll %s -check-prefix=LLVM
+void b(void *__attribute__((pass_object_size(0))));
+void e(void *__attribute__((pass_object_size(2))));
+void c() {
+  int a;
+  int d[a];
+  b(d);
+  e(d);
+}
+
+// CIR: cir.func no_proto @c()
+// CIR: [[TMP0:%.*]] = cir.alloca !s32i, cir.ptr <!s32i>, %{{[0-9]+}} : !u64i, ["vla"] {alignment = 16 : i64}
+// CIR: [[TMP1:%.*]] = cir.cast(bitcast, [[TMP0]] : !cir.ptr<!s32i>), !cir.ptr<!void>
+// CIR-NEXT: [[TMP2:%.*]] = cir.objsize([[TMP1]] : <!void>, max) -> !u64i
+// CIR-NEXT: cir.call @b([[TMP1]], [[TMP2]]) : (!cir.ptr<!void>, !u64i) -> ()
+// CIR: [[TMP3:%.*]] = cir.cast(bitcast, [[TMP0]] : !cir.ptr<!s32i>), !cir.ptr<!void>
+// CIR: [[TMP4:%.*]] = cir.objsize([[TMP3]] : <!void>, min) -> !u64i
+// CIR-NEXT: cir.call @e([[TMP3]], [[TMP4]]) : (!cir.ptr<!void>, !u64i) -> ()
+
+// LLVM: define void @c()
+// LLVM: [[TMP0:%.*]] = alloca i32, i64 %{{[0-9]+}},
+// LLVM: [[TMP1:%.*]] = call i64 @llvm.objectsize.i64.p0(ptr [[TMP0]], i1 false, i1 true, i1 false),
+// LLVM-NEXT: call void @b(ptr [[TMP0]], i64 [[TMP1]])
+// LLVM: [[TMP2:%.*]] = call i64 @llvm.objectsize.i64.p0(ptr [[TMP0]], i1 true, i1 true, i1 false),
+// LLVM-NEXT: call void @e(ptr [[TMP0]], i64 [[TMP2]])