diff --git a/clang/include/clang/CIR/Passes.h b/clang/include/clang/CIR/Passes.h
new file mode 100644
index 0000000000000..1d202ce5bfb52
--- /dev/null
+++ b/clang/include/clang/CIR/Passes.h
@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file exposes the entry points to create compiler passes for ClangIR.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_CIR_PASSES_H
+#define CLANG_CIR_PASSES_H
+
+#include "mlir/Pass/Pass.h"
+
+#include <memory>
+
+namespace cir {
+namespace direct {
+/// Create a pass that fully lowers CIR to the LLVMIR dialect.
+std::unique_ptr<mlir::Pass> createConvertCIRToLLVMPass();
+
+/// Adds passes that fully lower CIR to the LLVMIR dialect.
+void populateCIRToLLVMPasses(mlir::OpPassManager &pm);
+
+} // namespace direct
+} // end namespace cir
+
+#endif // CLANG_CIR_PASSES_H
diff --git a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
index 235b5a057852a..ba7fab2865116 100644
--- a/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
+++ b/clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp
@@ -27,6 +27,7 @@
 #include "clang/CIR/Dialect/IR/CIRAttrVisitor.h"
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
 #include "clang/CIR/MissingFeatures.h"
+#include "clang/CIR/Passes.h"
 #include "llvm/IR/Module.h"
 #include "llvm/Support/TimeProfiler.h"
 
@@ -304,11 +305,11 @@ void ConvertCIRToLLVMPass::runOnOperation() {
     signalPassFailure();
 }
 
-static std::unique_ptr<mlir::Pass> createConvertCIRToLLVMPass() {
+std::unique_ptr<mlir::Pass> createConvertCIRToLLVMPass() {
   return std::make_unique<ConvertCIRToLLVMPass>();
 }
 
-static void populateCIRToLLVMPasses(mlir::OpPassManager &pm) {
+void populateCIRToLLVMPasses(mlir::OpPassManager &pm) {
   pm.addPass(createConvertCIRToLLVMPass());
 }
 
diff --git a/clang/test/CIR/IR/func.cir b/clang/test/CIR/IR/func.cir
new file mode 100644
index 0000000000000..a32c3e697ed25
--- /dev/null
+++ b/clang/test/CIR/IR/func.cir
@@ -0,0 +1,85 @@
+// RUN: cir-opt %s | FileCheck %s
+
+module {
+// void empty() { }
+cir.func @empty() -> !cir.void {
+  cir.return
+}
+// CHECK: cir.func @empty() -> !cir.void {
+// CHECK:   cir.return
+// CHECK: }
+
+// void voidret() { return; }
+cir.func @voidret() -> !cir.void {
+  cir.return
+}
+// CHECK: cir.func @voidret() -> !cir.void {
+// CHECK:   cir.return
+// CHECK: }
+
+// int intfunc() { return 42; }
+cir.func @intfunc() -> !cir.int<s, 32> {
+  %0 = cir.const #cir.int<42> : !cir.int<s, 32>
+  cir.return %0 : !cir.int<s, 32>
+}
+// CHECK: cir.func @intfunc() -> !cir.int<s, 32> {
+// CHECK:   %[[VAL:.*]] = cir.const #cir.int<42> : !cir.int<s, 32>
+// CHECK:   cir.return %[[VAL]] : !cir.int<s, 32>
+// CHECK: }
+
+// int scopes() {
+//  {
+//    {
+//      return 99;
+//    }
+//  }
+//}
+cir.func @scopes() -> !cir.int<s, 32> {
+  cir.scope {
+    cir.scope {
+      %0 = cir.const #cir.int<99> : !cir.int<s, 32>
+      cir.return %0 : !cir.int<s, 32>
+    }
+  }
+  cir.trap
+}
+// CHECK: cir.func @scopes() -> !cir.int<s, 32> {
+// CHECK:   cir.scope {
+// CHECK:     cir.scope {
+// CHECK:       %[[VAL:.*]] = cir.const #cir.int<99> : !cir.int<s, 32>
+// CHECK:       cir.return %[[VAL]] : !cir.int<s, 32>
+// CHECK:     }
+// CHECK:   }
+// CHECK:   cir.trap
+// CHECK: }
+
+// long longfunc() { return 42l; }
+cir.func @longfunc() -> !cir.int<s, 64> {
+  %0 = cir.const #cir.int<42> : !cir.int<s, 64>
+  cir.return %0 : !cir.int<s, 64>
+}
+// CHECK: cir.func @longfunc() -> !cir.int<s, 64>
+// CHECK:   %0 = cir.const #cir.int<42> : !cir.int<s, 64>
+// CHECK:   cir.return %0 : !cir.int<s, 64>
+// CHECK: }
+
+// unsigned unsignedfunc() { return 42u; }
+cir.func @unsignedfunc() -> !cir.int<u, 32> {
+  %0 = cir.const #cir.int<42> : !cir.int<u, 32>
+  cir.return %0 : !cir.int<u, 32>
+}
+// CHECK: cir.func @unsignedfunc() -> !cir.int<u, 32>
+// CHECK:   %[[VAL:.*]] = cir.const #cir.int<42> : !cir.int<u, 32>
+// CHECK:   cir.return %[[VAL]] : !cir.int<u, 32>
+// CHECK: }
+
+// unsigned long long ullfunc() { return 42ull; }
+cir.func @ullfunc() -> !cir.int<u, 64> {
+  %0 = cir.const #cir.int<42> : !cir.int<u, 64>
+  cir.return %0 : !cir.int<u, 64>
+}
+// CHECK: cir.func @ullfunc() -> !cir.int<u, 64>
+// CHECK:   %[[VAL:.*]] = cir.const #cir.int<42> : !cir.int<u, 64>
+// CHECK:   cir.return %[[VAL:.*]] : !cir.int<u, 64>
+// CHECK: }
+}
diff --git a/clang/test/CIR/IR/global.cir b/clang/test/CIR/IR/global.cir
new file mode 100644
index 0000000000000..6c68ab0a501ff
--- /dev/null
+++ b/clang/test/CIR/IR/global.cir
@@ -0,0 +1,69 @@
+// RUN: cir-opt %s -o - | FileCheck %s
+
+module attributes {cir.triple = "x86_64-unknown-linux-gnu"} {
+  cir.global @c : !cir.int<s, 8>
+  cir.global @sc : !cir.int<s, 8>
+  cir.global @uc : !cir.int<u, 8>
+  cir.global @ss : !cir.int<s, 16>
+  cir.global @us = #cir.int<100> : !cir.int<u, 16>
+  cir.global @si = #cir.int<42> : !cir.int<s, 32>
+  cir.global @ui : !cir.int<u, 32>
+  cir.global @sl : !cir.int<s, 64>
+  cir.global @ul : !cir.int<u, 64>
+  cir.global @sll : !cir.int<s, 64>
+  cir.global @ull = #cir.int<123456> : !cir.int<u, 64>
+  cir.global @s128 : !cir.int<s, 128>
+  cir.global @u128 : !cir.int<u, 128>
+  cir.global @wc : !cir.int<s, 32>
+  cir.global @c8 : !cir.int<u, 8>
+  cir.global @c16 : !cir.int<u, 16>
+  cir.global @c32 : !cir.int<u, 32>
+  cir.global @sb20 : !cir.int<s, 20>
+  cir.global @ub48 : !cir.int<u, 48>
+  cir.global @f16 : !cir.f16
+  cir.global @bf16 : !cir.bf16
+  cir.global @f : !cir.float
+  cir.global @d = #cir.fp<1.250000e+00> : !cir.double
+  cir.global @ld : !cir.long_double<!cir.f80>
+  cir.global @f128 : !cir.f128
+  cir.global @vp : !cir.ptr<!cir.void>
+  cir.global @ip = #cir.ptr<null> : !cir.ptr<!cir.int<s, 32>>
+  cir.global @dp : !cir.ptr<!cir.double>
+  cir.global @cpp : !cir.ptr<!cir.ptr<!cir.int<s, 8>>>
+  cir.global @fp : !cir.ptr<!cir.func<!cir.void ()>>
+  cir.global @fpii = #cir.ptr<null> : !cir.ptr<!cir.func<!cir.int<s, 32> (!cir.int<s, 32>)>>
+  cir.global @fpvar : !cir.ptr<!cir.func<!cir.void (!cir.int<s, 32>, ...)>>
+}
+
+// CHECK: cir.global @c : !cir.int<s, 8>
+// CHECK: cir.global @sc : !cir.int<s, 8>
+// CHECK: cir.global @uc : !cir.int<u, 8>
+// CHECK: cir.global @ss : !cir.int<s, 16>
+// CHECK: cir.global @us = #cir.int<100>
+// CHECK: cir.global @si = #cir.int<42>
+// CHECK: cir.global @ui : !cir.int<u, 32>
+// CHECK: cir.global @sl : !cir.int<s, 64>
+// CHECK: cir.global @ul : !cir.int<u, 64>
+// CHECK: cir.global @sll : !cir.int<s, 64>
+// CHECK: cir.global @ull = #cir.int<123456> : !cir.int<u, 64>
+// CHECK: cir.global @s128 : !cir.int<s, 128>
+// CHECK: cir.global @u128 : !cir.int<u, 128>
+// CHECK: cir.global @wc : !cir.int<s, 32>
+// CHECK: cir.global @c8 : !cir.int<u, 8>
+// CHECK: cir.global @c16 : !cir.int<u, 16>
+// CHECK: cir.global @c32 : !cir.int<u, 32>
+// CHECK: cir.global @sb20 : !cir.int<s, 20>
+// CHECK: cir.global @ub48 : !cir.int<u, 48>
+// CHECK: cir.global @f16 : !cir.f16
+// CHECK: cir.global @bf16 : !cir.bf16
+// CHECK: cir.global @f : !cir.float
+// CHECK: cir.global @d = #cir.fp<1.250000e+00> : !cir.double
+// CHECK: cir.global @ld : !cir.long_double<!cir.f80>
+// CHECK: cir.global @f128 : !cir.f128
+// CHECK: cir.global @vp : !cir.ptr<!cir.void>
+// CHECK: cir.global @ip = #cir.ptr<null> : !cir.ptr<!cir.int<s, 32>>
+// CHECK: cir.global @dp : !cir.ptr<!cir.double>
+// CHECK: cir.global @cpp : !cir.ptr<!cir.ptr<!cir.int<s, 8>>>
+// CHECK: cir.global @fp : !cir.ptr<!cir.func<!cir.void ()>>
+// CHECK: cir.global @fpii = #cir.ptr<null> : !cir.ptr<!cir.func<!cir.int<s, 32> (!cir.int<s, 32>)>>
+// CHECK: cir.global @fpvar : !cir.ptr<!cir.func<!cir.void (!cir.int<s, 32>, ...)>>
diff --git a/clang/test/CMakeLists.txt b/clang/test/CMakeLists.txt
index 4ff81e7055c57..1c93e2b0d9844 100644
--- a/clang/test/CMakeLists.txt
+++ b/clang/test/CMakeLists.txt
@@ -85,7 +85,13 @@ list(APPEND CLANG_TEST_DEPS
   diagtool
   hmaptool
   )
-  
+
+if(CLANG_ENABLE_CIR)
+  list(APPEND CLANG_TEST_DEPS
+    cir-opt
+    )
+endif()
+
 if(CLANG_ENABLE_STATIC_ANALYZER)
   list(APPEND CLANG_TEST_DEPS
     clang-check
diff --git a/clang/test/lit.cfg.py b/clang/test/lit.cfg.py
index e4b39c4f71597..9820ddd1f14af 100644
--- a/clang/test/lit.cfg.py
+++ b/clang/test/lit.cfg.py
@@ -29,6 +29,7 @@
     ".c",
     ".cpp",
     ".i",
+    ".cir",
     ".cppm",
     ".m",
     ".mm",
@@ -85,6 +86,7 @@
 tools = [
     "apinotes-test",
     "c-index-test",
+    "cir-opt",
     "clang-diff",
     "clang-format",
     "clang-repl",
diff --git a/clang/tools/CMakeLists.txt b/clang/tools/CMakeLists.txt
index de0b47f3751f1..ae3414e177192 100644
--- a/clang/tools/CMakeLists.txt
+++ b/clang/tools/CMakeLists.txt
@@ -3,6 +3,9 @@ create_subdirectory_options(CLANG TOOL)
 add_clang_subdirectory(diagtool)
 add_clang_subdirectory(driver)
 add_clang_subdirectory(apinotes-test)
+if(CLANG_ENABLE_CIR)
+  add_clang_subdirectory(cir-opt)
+endif()
 add_clang_subdirectory(clang-diff)
 add_clang_subdirectory(clang-format)
 add_clang_subdirectory(clang-fuzzer)
diff --git a/clang/tools/cir-opt/CMakeLists.txt b/clang/tools/cir-opt/CMakeLists.txt
new file mode 100644
index 0000000000000..75bec5f4e1b0b
--- /dev/null
+++ b/clang/tools/cir-opt/CMakeLists.txt
@@ -0,0 +1,32 @@
+get_property(dialect_libs GLOBAL PROPERTY MLIR_DIALECT_LIBS)
+get_property(conversion_libs GLOBAL PROPERTY MLIR_CONVERSION_LIBS)
+
+include_directories(${LLVM_MAIN_SRC_DIR}/../mlir/include)
+include_directories(${CMAKE_BINARY_DIR}/tools/mlir/include)
+
+add_clang_tool(cir-opt
+  cir-opt.cpp
+)
+
+clang_target_link_libraries(cir-opt
+  PRIVATE
+  clangCIR
+  clangCIRLoweringDirectToLLVM
+  MLIRCIR
+)
+
+target_link_libraries(cir-opt
+  PRIVATE
+  ${dialect_libs}
+  ${conversion_libs}
+  MLIRAnalysis
+  MLIRDialect
+  MLIRIR
+  MLIRMemRefDialect
+  MLIROptLib
+  MLIRParser
+  MLIRPass
+  MLIRSideEffectInterfaces
+  MLIRTransforms
+  MLIRTransformUtils
+)
diff --git a/clang/tools/cir-opt/cir-opt.cpp b/clang/tools/cir-opt/cir-opt.cpp
new file mode 100644
index 0000000000000..0c0f6dcd9eecf
--- /dev/null
+++ b/clang/tools/cir-opt/cir-opt.cpp
@@ -0,0 +1,46 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Similar to MLIR/LLVM's "opt" tools but also deals with analysis and custom
+// arguments. TODO: this is basically a copy from MlirOptMain.cpp, but capable
+// of module emission as specified by the user.
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Conversion/ReconcileUnrealizedCasts/ReconcileUnrealizedCasts.h"
+#include "mlir/Dialect/Func/IR/FuncOps.h"
+#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
+#include "mlir/Dialect/MemRef/IR/MemRef.h"
+#include "mlir/InitAllPasses.h"
+#include "mlir/Pass/PassManager.h"
+#include "mlir/Pass/PassOptions.h"
+#include "mlir/Pass/PassRegistry.h"
+#include "mlir/Tools/mlir-opt/MlirOptMain.h"
+#include "clang/CIR/Dialect/IR/CIRDialect.h"
+#include "clang/CIR/Passes.h"
+
+struct CIRToLLVMPipelineOptions
+    : public mlir::PassPipelineOptions<CIRToLLVMPipelineOptions> {};
+
+int main(int argc, char **argv) {
+  // TODO: register needed MLIR passes for CIR?
+  mlir::DialectRegistry registry;
+  registry.insert<mlir::BuiltinDialect, cir::CIRDialect,
+                  mlir::memref::MemRefDialect, mlir::LLVM::LLVMDialect>();
+
+  mlir::PassPipelineRegistration<CIRToLLVMPipelineOptions> pipeline(
+      "cir-to-llvm", "",
+      [](mlir::OpPassManager &pm, const CIRToLLVMPipelineOptions &options) {
+        cir::direct::populateCIRToLLVMPasses(pm);
+      });
+
+  mlir::registerTransformsPasses();
+
+  return mlir::asMainReturnCode(MlirOptMain(
+      argc, argv, "Clang IR analysis and optimization tool\n", registry));
+}