[Clang][LoongArch] Implement __builtin_loongarch_dbar builtin

[SixWeining]

llvm/include/llvm/IR/IntrinsicsLoongArch.td

45

Seems this arg is unnecessary because the defalut value is [].

[gonglingqin]

llvm/include/llvm/IR/IntrinsicsLoongArch.td

45

Thanks, I will modify it.

[gonglingqin]

Address @SixWeining's comments.

[SixWeining]

LGTM but let's wait others.

[SixWeining]

llvm/test/CodeGen/LoongArch/intrinsic-error.ll

11

It's better to add a test that immediate is out of range.

[gonglingqin]

llvm/test/CodeGen/LoongArch/intrinsic-error.ll

11

Thanks, I will add test cases.

[gonglingqin]

Add test cases to detect whether the immediate is out of range.

[WowbaggersLiquidLunch]

Hi, this seems to be causing some problems when generating Xcode project.

When I try to generate the Xcode project with the following command:

cmake -G "Xcode" -DCMAKE_BUILD_TYPE=Debug -DLLVM_TARGETS_TO_BUILD="X86" -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_OPTIMIZED_TABLEGEN=ON -DLLVM_ENABLE_IDE=ON -DLLVM_CCACHE_BUILD=ON ../../llvm

I get the following error:

CMake Error in /path/to/llvm-project/clang/lib/Headers/CMakeLists.txt:

The custom command generating

  /path/to/llvm-project/build/Xcode-Debug/$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)/lib/clang/16/include/larchintrin.h

is attached to multiple targets:

  clang-resource-headers
  loongarch-resource-headers

but none of these is a common dependency of the other(s).  This is not
allowed by the Xcode "new build system".

CMake Error in /path/to/llvm-project/third-party/benchmark/CMakeLists.txt:

The custom command generating

  /path/to/llvm-project/build/Xcode-Debug/$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)/lib/clang/16/include/larchintrin.h

is attached to multiple targets:

  clang-resource-headers
  loongarch-resource-headers

but none of these is a common dependency of the other(s).  This is not
allowed by the Xcode "new build system".

[gonglingqin]

In D136906#3940289, @WowbaggersLiquidLunch wrote:

Hi, this seems to be causing some problems when generating Xcode project.

When I try to generate the Xcode project with the following command:

cmake -G "Xcode" -DCMAKE_BUILD_TYPE=Debug -DLLVM_TARGETS_TO_BUILD="X86" -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_OPTIMIZED_TABLEGEN=ON -DLLVM_ENABLE_IDE=ON -DLLVM_CCACHE_BUILD=ON ../../llvm

I get the following error:

CMake Error in /path/to/llvm-project/clang/lib/Headers/CMakeLists.txt:

The custom command generating

  /path/to/llvm-project/build/Xcode-Debug/$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)/lib/clang/16/include/larchintrin.h

is attached to multiple targets:

  clang-resource-headers
  loongarch-resource-headers

but none of these is a common dependency of the other(s).  This is not
allowed by the Xcode "new build system".

CMake Error in /path/to/llvm-project/third-party/benchmark/CMakeLists.txt:

The custom command generating

  /path/to/llvm-project/build/Xcode-Debug/$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)/lib/clang/16/include/larchintrin.h

is attached to multiple targets:

  clang-resource-headers
  loongarch-resource-headers

but none of these is a common dependency of the other(s).  This is not
allowed by the Xcode "new build system".

Thank you for your input. Correct me if I'm wrong, when I create a new build directory and execute the following command:

cmake -G "Xcode" -DCMAKE_BUILD_TYPE=Debug -DLLVM_TARGETS_TO_BUILD="X86" -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_OPTIMIZED_TABLEGEN=ON -DLLVM_ENABLE_IDE=ON -DLLVM_CCACHE_BUILD=ON ../../llvm

I get the following error:

CMake Error: Could not create named generator Xcode

Generators
  Unix Makefiles               = Generates standard UNIX makefiles.
  Ninja                        = Generates build.ninja files.
  Watcom WMake                 = Generates Watcom WMake makefiles.
  CodeBlocks - Ninja           = Generates CodeBlocks project files.
  CodeBlocks - Unix Makefiles  = Generates CodeBlocks project files.
  CodeLite - Ninja             = Generates CodeLite project files.
  CodeLite - Unix Makefiles    = Generates CodeLite project files.
  Sublime Text 2 - Ninja       = Generates Sublime Text 2 project files.
  Sublime Text 2 - Unix Makefiles
                               = Generates Sublime Text 2 project files.
  Kate - Ninja                 = Generates Kate project files.
  Kate - Unix Makefiles        = Generates Kate project files.
  Eclipse CDT4 - Ninja         = Generates Eclipse CDT 4.0 project files.
  Eclipse CDT4 - Unix Makefiles= Generates Eclipse CDT 4.0 project files.

But when I change Xcode to Ninja, no error output is generated.
Do you have any suggestions for reproducing the bugs you mentioned?

[gonglingqin]

In D136906#3940289, @WowbaggersLiquidLunch wrote:

Hi, this seems to be causing some problems when generating Xcode project.

When I try to generate the Xcode project with the following command:

cmake -G "Xcode" -DCMAKE_BUILD_TYPE=Debug -DLLVM_TARGETS_TO_BUILD="X86" -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_OPTIMIZED_TABLEGEN=ON -DLLVM_ENABLE_IDE=ON -DLLVM_CCACHE_BUILD=ON ../../llvm

I get the following error:

CMake Error in /path/to/llvm-project/clang/lib/Headers/CMakeLists.txt:

The custom command generating

  /path/to/llvm-project/build/Xcode-Debug/$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)/lib/clang/16/include/larchintrin.h

is attached to multiple targets:

  clang-resource-headers
  loongarch-resource-headers

but none of these is a common dependency of the other(s).  This is not
allowed by the Xcode "new build system".

CMake Error in /path/to/llvm-project/third-party/benchmark/CMakeLists.txt:

The custom command generating

  /path/to/llvm-project/build/Xcode-Debug/$(CONFIGURATION)$(EFFECTIVE_PLATFORM_NAME)/lib/clang/16/include/larchintrin.h

is attached to multiple targets:

  clang-resource-headers
  loongarch-resource-headers

but none of these is a common dependency of the other(s).  This is not
allowed by the Xcode "new build system".

I realized that it might be my environment that prevented me from repeating this problem. Can you use https://reviews.llvm.org/D138403 to solve this problem?

[WowbaggersLiquidLunch]

I get the following error:

CMake Error: Could not create named generator Xcode

Sorry, I forgot to mention that Xcode is only available on macOS.

But when I change Xcode to Ninja, no error output is generated.

Indeed. Ninja works fine for me as well. The problem is I kind of need both Xcode and Ninja in my workflow (Xcode for editing, Ninja for building).

Do you have any suggestions for reproducing the bugs you mentioned?

I think the following steps should be able to reproduce the error messages I'm seeing (It's a bit long):

1. Install macOS 12.6 or newer. (I'm currently on 12.6, but newer versions such as 12.6.1 and 13 (the latest) should produce the same error messages.)

2. Install Xcode 14.1 and/or the Xcode command line tools
   • Xcode can be installed via this link (generally recommended), or from the Mac App Store via this link.
     • The first link downloads a .xip file which can take a long time to decompress. This step can be sped up significantly by decompressing the file using this tool.
   • The command line tools can be installed via this link, via the following commands, or by launching Xcode after it's installed. (I don't remember it clearly, but I think you probably can skip this step and have Homebrew install it for you in step 3)
     
     sudo rm -rf /Library/Developer/CommandLineTools
     
     sudo xcode-select --install

3. Install LLVM's dependencies via Homebrew
   • First we need to install brew using the following command
     
     /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
   • Then install Cmake and Python with brew. (I'm not sure if Python is really needed)
     
     brew install cmake python

4. Clone LLVM and create the build directory.
5. Generate Xcode project using CMake.
   
   cmake -G "Xcode" -DCMAKE_BUILD_TYPE=Debug -DLLVM_TARGETS_TO_BUILD="X86" -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_OPTIMIZED_TABLEGEN=ON -DLLVM_ENABLE_IDE=ON -DLLVM_CCACHE_BUILD=ON path/to/llvm
   
   Flags other than -G "Xcode" probably are optional for the purpose of reproducing the error messages.

[WowbaggersLiquidLunch]

In D136906#3940377, @gonglingqin wrote:

Can you use https://reviews.llvm.org/D138403 to solve this problem?

Thanks for letting me know. I'll give it a try.

[gonglingqin]

In D136906#3940427, @WowbaggersLiquidLunch wrote:

I get the following error:

CMake Error: Could not create named generator Xcode

Sorry, I forgot to mention that Xcode is only available on macOS.

But when I change Xcode to Ninja, no error output is generated.

Indeed. Ninja works fine for me as well. The problem is I kind of need both Xcode and Ninja in my workflow (Xcode for editing, Ninja for building).

Do you have any suggestions for reproducing the bugs you mentioned?

I think the following steps should be able to reproduce the error messages I'm seeing (It's a bit long):

1. Install macOS 12.6 or newer. (I'm currently on 12.6, but newer versions such as 12.6.1 and 13 (the latest) should produce the same error messages.)

2. Install Xcode 14.1 and/or the Xcode command line tools
   • Xcode can be installed via this link (generally recommended), or from the Mac App Store via this link.
     • The first link downloads a .xip file which can take a long time to decompress. This step can be sped up significantly by decompressing the file using this tool.
   • The command line tools can be installed via this link, via the following commands, or by launching Xcode after it's installed. (I don't remember it clearly, but I think you probably can skip this step and have Homebrew install it for you in step 3)
     
     sudo rm -rf /Library/Developer/CommandLineTools
     
     sudo xcode-select --install

3. Install LLVM's dependencies via Homebrew
   • First we need to install brew using the following command
     
     /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"
   • Then install Cmake and Python with brew. (I'm not sure if Python is really needed)
     
     brew install cmake python

4. Clone LLVM and create the build directory.
5. Generate Xcode project using CMake.
   
   cmake -G "Xcode" -DCMAKE_BUILD_TYPE=Debug -DLLVM_TARGETS_TO_BUILD="X86" -DLLVM_ENABLE_PROJECTS="clang" -DLLVM_OPTIMIZED_TABLEGEN=ON -DLLVM_ENABLE_IDE=ON -DLLVM_CCACHE_BUILD=ON path/to/llvm
   
   Flags other than -G "Xcode" probably are optional for the purpose of reproducing the error messages.

Thanks! Very nice to know.

[gonglingqin]

In D136906#3940432, @WowbaggersLiquidLunch wrote:

In D136906#3940377, @gonglingqin wrote:

Can you use https://reviews.llvm.org/D138403 to solve this problem?

Thanks for letting me know. I'll give it a try.

Thanks a lot!

clang/include/clang/Basic/BuiltinsLoongArch.def

+//==- BuiltinsLoongArch.def - LoongArch Builtin function database -- C++ -*-==//
+//
+// 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 defines the LoongArch-specific builtin function database.  Users of
+// this file must define the BUILTIN macro to make use of this information.
+//
+//===----------------------------------------------------------------------===//
+
+#if defined(BUILTIN) && !defined(TARGET_BUILTIN)
+#   define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE) BUILTIN(ID, TYPE, ATTRS)
+#endif
+
+// TODO: Support more builtins.
+// TODO: Added feature constraints.
+TARGET_BUILTIN(__builtin_loongarch_dbar, "vIUi", "nc", "")
+
+#undef BUILTIN
+#undef TARGET_BUILTIN

clang/include/clang/Basic/TargetBuiltins.h

enum {
     FirstRVVBuiltin = clang::Builtin::FirstTSBuiltin,
     LastRVVBuiltin = RISCVVector::FirstTSBuiltin - 1,
 #define BUILTIN(ID, TYPE, ATTRS) BI##ID,
 #include "clang/Basic/BuiltinsRISCV.def"
     LastTSBuiltin
   };
   } // namespace RISCV
 
+  /// LoongArch builtins
+  namespace LoongArch {
+  enum {
+    LastTIBuiltin = clang::Builtin::FirstTSBuiltin - 1,
+#define BUILTIN(ID, TYPE, ATTRS) BI##ID,
+#include "clang/Basic/BuiltinsLoongArch.def"
+    LastTSBuiltin
+  };
+  } // namespace LoongArch
+
   /// Flags to identify the types for overloaded Neon builtins.
   ///
   /// These must be kept in sync with the flags in utils/TableGen/NeonEmitter.h.
   class NeonTypeFlags {
     enum {
       EltTypeMask = 0xf,
       UnsignedFlag = 0x10,
       QuadFlag = 0x20

clang/include/clang/module.modulemap

module Clang_Basic {
   textual header "Basic/BuiltinsAArch64NeonSVEBridge.def"
   textual header "Basic/BuiltinsAArch64NeonSVEBridge_cg.def"
   textual header "Basic/BuiltinsARM.def"
   textual header "Basic/BuiltinsBPF.def"
   textual header "Basic/Builtins.def"
   textual header "Basic/BuiltinsHexagon.def"
   textual header "Basic/BuiltinsHexagonDep.def"
   textual header "Basic/BuiltinsHexagonMapCustomDep.def"
+  textual header "Basic/BuiltinsLoongArch.def"
   textual header "Basic/BuiltinsMips.def"
   textual header "Basic/BuiltinsNEON.def"
   textual header "Basic/BuiltinsNVPTX.def"
   textual header "Basic/BuiltinsPPC.def"
   textual header "Basic/BuiltinsRISCV.def"
   textual header "Basic/BuiltinsRISCVVector.def"
   textual header "Basic/BuiltinsSVE.def"
   textual header "Basic/BuiltinsSystemZ.def"

clang/lib/Basic/Targets/LoongArch.h

 namespace clang {
 namespace targets {
 
 class LLVM_LIBRARY_VISIBILITY LoongArchTargetInfo : public TargetInfo {
 protected:
   std::string ABI;
   bool HasFeatureD;
   bool HasFeatureF;
+  static const Builtin::Info BuiltinInfo[];
 
 public:
   LoongArchTargetInfo(const llvm::Triple &Triple, const TargetOptions &)
       : TargetInfo(Triple) {
     HasFeatureD = false;
     HasFeatureF = false;
     LongDoubleWidth = 128;
     LongDoubleAlign = 128;

clang/lib/Basic/Targets/LoongArch.cpp

void LoongArchTargetInfo::getTargetDefines(const LangOptions &Opts,
   } else if (ABI == "lp64f" || ABI == "ilp32f") {
     Builder.defineMacro("__loongarch_hard_float");
     Builder.defineMacro("__loongarch_single_float");
   } else if (ABI == "lp64s" || ABI == "ilp32s") {
     Builder.defineMacro("__loongarch_soft_float");
   }
 }
 
+const Builtin::Info LoongArchTargetInfo::BuiltinInfo[] = {
+#define BUILTIN(ID, TYPE, ATTRS)                                               \
+  {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr},
+#define TARGET_BUILTIN(ID, TYPE, ATTRS, FEATURE)                               \
+  {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, FEATURE},
+#include "clang/Basic/BuiltinsLoongArch.def"
+};
+
 ArrayRef<Builtin::Info> LoongArchTargetInfo::getTargetBuiltins() const {
-  // TODO: To be implemented in future.
-  return {};
+  return llvm::makeArrayRef(BuiltinInfo, clang::LoongArch::LastTSBuiltin -
+                                             Builtin::FirstTSBuiltin);
 }
 
 bool LoongArchTargetInfo::handleTargetFeatures(
     std::vector<std::string> &Features, DiagnosticsEngine &Diags) {
   for (const auto &Feature : Features) {
     if (Feature == "+d" || Feature == "+f") {
       // "d" implies "f".
       HasFeatureF = true;
       if (Feature == "+d") {
         HasFeatureD = true;
       }
     }
   }
   return true;
 }

clang/lib/CodeGen/CGBuiltin.cpp

 #include "llvm/IR/DataLayout.h"
 #include "llvm/IR/InlineAsm.h"
 #include "llvm/IR/Intrinsics.h"
 #include "llvm/IR/IntrinsicsAArch64.h"
 #include "llvm/IR/IntrinsicsAMDGPU.h"
 #include "llvm/IR/IntrinsicsARM.h"
 #include "llvm/IR/IntrinsicsBPF.h"
 #include "llvm/IR/IntrinsicsHexagon.h"
+#include "llvm/IR/IntrinsicsLoongArch.h"
 #include "llvm/IR/IntrinsicsNVPTX.h"
 #include "llvm/IR/IntrinsicsPowerPC.h"
 #include "llvm/IR/IntrinsicsR600.h"
 #include "llvm/IR/IntrinsicsRISCV.h"
 #include "llvm/IR/IntrinsicsS390.h"
 #include "llvm/IR/IntrinsicsVE.h"
 #include "llvm/IR/IntrinsicsWebAssembly.h"
 #include "llvm/IR/IntrinsicsX86.h"
static Value *EmitTargetArchBuiltinExpr(CodeGenFunction *CGF,
   case llvm::Triple::wasm32:
   case llvm::Triple::wasm64:
     return CGF->EmitWebAssemblyBuiltinExpr(BuiltinID, E);
   case llvm::Triple::hexagon:
     return CGF->EmitHexagonBuiltinExpr(BuiltinID, E);
   case llvm::Triple::riscv32:
   case llvm::Triple::riscv64:
     return CGF->EmitRISCVBuiltinExpr(BuiltinID, E, ReturnValue);
+  case llvm::Triple::loongarch32:
+  case llvm::Triple::loongarch64:
+    return CGF->EmitLoongArchBuiltinExpr(BuiltinID, E);
   default:
     return nullptr;
   }
 }
 
 Value *CodeGenFunction::EmitTargetBuiltinExpr(unsigned BuiltinID,
                                               const CallExpr *E,
                                               ReturnValueSlot ReturnValue) {

 #include "clang/Basic/riscv_vector_builtin_cg.inc"
   }
 
   assert(ID != Intrinsic::not_intrinsic);
 
   llvm::Function *F = CGM.getIntrinsic(ID, IntrinsicTypes);
   return Builder.CreateCall(F, Ops, "");
 }
+
+Value *CodeGenFunction::EmitLoongArchBuiltinExpr(unsigned BuiltinID,
+                                                 const CallExpr *E) {
+  SmallVector<Value *, 4> Ops;
+
+  for (unsigned i = 0, e = E->getNumArgs(); i != e; i++)
+    Ops.push_back(EmitScalarExpr(E->getArg(i)));
+
+  Intrinsic::ID ID = Intrinsic::not_intrinsic;
+
+  switch (BuiltinID) {
+  default:
+    llvm_unreachable("unexpected builtin ID.");
+  case LoongArch::BI__builtin_loongarch_dbar:
+    ID = Intrinsic::loongarch_dbar;
+    break;
+    // TODO: Support more Intrinsics.
+  }
+
+  assert(ID != Intrinsic::not_intrinsic);
+
+  llvm::Function *F = CGM.getIntrinsic(ID);
+  return Builder.CreateCall(F, Ops);
+}

clang/lib/CodeGen/CodeGenFunction.h

public:
   llvm::Value *EmitAMDGPUBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitSystemZBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitNVPTXBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitWebAssemblyBuiltinExpr(unsigned BuiltinID,
                                           const CallExpr *E);
   llvm::Value *EmitHexagonBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   llvm::Value *EmitRISCVBuiltinExpr(unsigned BuiltinID, const CallExpr *E,
                                     ReturnValueSlot ReturnValue);
+  llvm::Value *EmitLoongArchBuiltinExpr(unsigned BuiltinID, const CallExpr *E);
   void ProcessOrderScopeAMDGCN(llvm::Value *Order, llvm::Value *Scope,
                                llvm::AtomicOrdering &AO,
                                llvm::SyncScope::ID &SSID);
 
   enum class MSVCIntrin;
   llvm::Value *EmitMSVCBuiltinExpr(MSVCIntrin BuiltinID, const CallExpr *E);
 
   llvm::Value *EmitBuiltinAvailable(const VersionTuple &Version);

clang/lib/Headers/CMakeLists.txt

set(hlsl_subdir_files
   hlsl/hlsl_basic_types.h
   hlsl/hlsl_intrinsics.h
   )
 set(hlsl_files
   ${hlsl_h}
   ${hlsl_subdir_files}
   )
 
+set(loongarch_files
+  larchintrin.h
+  )
+
 set(mips_msa_files
   msa.h
   )
 
 set(opencl_files
   opencl-c.h
   opencl-c-base.h
   )

 set(files
   ${core_files}
   ${arm_common_files}
   ${arm_only_files}
   ${aarch64_only_files}
   ${cuda_files}
   ${hexagon_files}
   ${hip_files}
+  ${loongarch_files}
   ${mips_msa_files}
   ${opencl_files}
   ${ppc_files}
   ${ppc_htm_files}
   ${systemz_files}
   ${ve_files}
   ${x86_files}
   ${webassembly_files}

 add_header_target("arm-common-resource-headers" "${arm_common_files};${arm_common_generated_files}")
 
 # Architecture/platform specific targets
 add_header_target("arm-resource-headers" "${arm_only_files};${arm_only_generated_files}")
 add_header_target("aarch64-resource-headers" "${aarch64_only_files};${aarch64_only_generated_files}")
 add_header_target("cuda-resource-headers" "${cuda_files};${cuda_wrapper_files}")
 add_header_target("hexagon-resource-headers" "${hexagon_files}")
 add_header_target("hip-resource-headers" "${hip_files}")
+add_header_target("loongarch-resource-headers" "${loongarch_files}")
 add_header_target("mips-resource-headers" "${mips_msa_files}")
 add_header_target("ppc-resource-headers" "${ppc_files};${ppc_wrapper_files}")
 add_header_target("ppc-htm-resource-headers" "${ppc_htm_files}")
 add_header_target("riscv-resource-headers" "${riscv_generated_files}")
 add_header_target("systemz-resource-headers" "${systemz_files}")
 add_header_target("ve-resource-headers" "${ve_files}")
 add_header_target("webassembly-resource-headers" "${webassembly_files}")
 add_header_target("x86-resource-headers" "${x86_files}")

 
 install(
   FILES ${hip_files}
   DESTINATION ${header_install_dir}
   EXCLUDE_FROM_ALL
   COMPONENT hip-resource-headers)
 
 install(
+  FILES ${loongarch_files}
+  DESTINATION ${header_install_dir}
+  EXCLUDE_FROM_ALL
+  COMPONENT loongarch-resource-headers)
+
+install(
   FILES ${mips_msa_files}
   DESTINATION ${header_install_dir}
   EXCLUDE_FROM_ALL
   COMPONENT mips-resource-headers)
 
 install(
   FILES ${ppc_wrapper_files}
   DESTINATION ${header_install_dir}/ppc_wrappers

clang/lib/Headers/larchintrin.h

+/*===------------ larchintrin.h - LoongArch intrinsics ---------------------===
+ *
+ * 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
+ *
+ *===-----------------------------------------------------------------------===
+ */
+
+#ifndef _LOONGARCH_BASE_INTRIN_H
+#define _LOONGARCH_BASE_INTRIN_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define __dbar(/*ui15*/ _1) __builtin_loongarch_dbar((_1))
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _LOONGARCH_BASE_INTRIN_H */

clang/test/CodeGen/LoongArch/intrinsic.c

+// NOTE: Assertions have been autogenerated by utils/update_cc_test_checks.py
+// RUN: %clang_cc1 -triple loongarch32 -emit-llvm %s -o - \
+// RUN:     | FileCheck %s -check-prefix=LA32
+// RUN: %clang_cc1 -triple loongarch64 -emit-llvm %s -o - \
+// RUN:     | FileCheck %s -check-prefix=LA64
+
+#include <larchintrin.h>
+
+// LA32-LABEL: @dbar(
+// LA32-NEXT:  entry:
+// LA32-NEXT:    call void @llvm.loongarch.dbar(i32 0)
+// LA32-NEXT:    ret void
+//
+// LA64-LABEL: @dbar(
+// LA64-NEXT:  entry:
+// LA64-NEXT:    call void @llvm.loongarch.dbar(i32 0)
+// LA64-NEXT:    ret void
+//
+void dbar() {
+  return __builtin_loongarch_dbar(0);
+}
+

llvm/include/llvm/IR/IntrinsicsLoongArch.td

 
 defm int_loongarch_masked_atomicrmw_xchg : MaskedAtomicRMWIntrinsics;
 defm int_loongarch_masked_atomicrmw_add : MaskedAtomicRMWIntrinsics;
 defm int_loongarch_masked_atomicrmw_sub : MaskedAtomicRMWIntrinsics;
 defm int_loongarch_masked_atomicrmw_nand : MaskedAtomicRMWIntrinsics;
 defm int_loongarch_masked_atomicrmw_umax : MaskedAtomicRMWIntrinsics;
 defm int_loongarch_masked_atomicrmw_umin : MaskedAtomicRMWIntrinsics;
 
 // @llvm.loongarch.masked.cmpxchg.i64.<p>(
 //   ptr addr, grlen cmpval, grlen newval, grlen mask, grlenimm ordering)
 defm int_loongarch_masked_cmpxchg : MaskedAtomicRMWFiveOpIntrinsics;
+
+def int_loongarch_dbar : Intrinsic<[], [llvm_i32_ty]>;
 } // TargetPrefix = "loongarch"

llvm/lib/Target/LoongArch/LoongArchISelLowering.h

enum NodeType : unsigned {
   BSTRINS,
   BSTRPICK,
 
   // Byte-swapping and bit-reversal
   REVB_2H,
   REVB_2W,
   BITREV_4B,
   BITREV_W,
+
+  // Intrinsic operations
+  DBAR,
 };
 } // end namespace LoongArchISD
 
 class LoongArchTargetLowering : public TargetLowering {
   const LoongArchSubtarget &Subtarget;
 
 public:
   explicit LoongArchTargetLowering(const TargetMachine &TM,
private:
   SDValue lowerConstantPool(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerEH_DWARF_CFA(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerFP_TO_SINT(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerBITCAST(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerUINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerSINT_TO_FP(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerVASTART(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerINTRINSIC_WO_CHAIN(SDValue Op, SelectionDAG &DAG) const;
+  SDValue lowerINTRINSIC_VOID(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerFRAMEADDR(SDValue Op, SelectionDAG &DAG) const;
   SDValue lowerRETURNADDR(SDValue Op, SelectionDAG &DAG) const;
 
   bool isFPImmLegal(const APFloat &Imm, EVT VT,
                     bool ForCodeSize) const override;
 
   bool shouldInsertFencesForAtomic(const Instruction *I) const override;
 

llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp

LoongArchTargetLowering::LoongArchTargetLowering(const TargetMachine &TM,
   setOperationAction(ISD::SHL_PARTS, GRLenVT, Custom);
   setOperationAction(ISD::SRA_PARTS, GRLenVT, Custom);
   setOperationAction(ISD::SRL_PARTS, GRLenVT, Custom);
   setOperationAction(ISD::FP_TO_SINT, GRLenVT, Custom);
   setOperationAction(ISD::ROTL, GRLenVT, Expand);
   setOperationAction(ISD::CTPOP, GRLenVT, Expand);
   setOperationAction(ISD::DEBUGTRAP, MVT::Other, Legal);
   setOperationAction(ISD::TRAP, MVT::Other, Legal);
+  setOperationAction(ISD::INTRINSIC_VOID, MVT::Other, Custom);
 
   setOperationAction({ISD::GlobalAddress, ISD::BlockAddress, ISD::ConstantPool,
                       ISD::JumpTable},
                      GRLenVT, Custom);
 
   setOperationAction(ISD::GlobalTLSAddress, GRLenVT, Custom);
 
   setOperationAction(ISD::INTRINSIC_WO_CHAIN, MVT::Other, Custom);
if (Subtarget.is64Bit()) {
     setOperationAction(ISD::SRA, MVT::i32, Custom);
     setOperationAction(ISD::SRL, MVT::i32, Custom);
     setOperationAction(ISD::FP_TO_SINT, MVT::i32, Custom);
     setOperationAction(ISD::BITCAST, MVT::i32, Custom);
     setOperationAction(ISD::ROTR, MVT::i32, Custom);
     setOperationAction(ISD::ROTL, MVT::i32, Custom);
     setOperationAction(ISD::CTTZ, MVT::i32, Custom);
     setOperationAction(ISD::CTLZ, MVT::i32, Custom);
+    setOperationAction(ISD::INTRINSIC_VOID, MVT::i32, Custom);
     if (Subtarget.hasBasicF() && !Subtarget.hasBasicD())
       setOperationAction(ISD::FP_TO_UINT, MVT::i32, Custom);
     if (Subtarget.hasBasicF())
       setOperationAction(ISD::FRINT, MVT::f32, Legal);
     if (Subtarget.hasBasicD())
       setOperationAction(ISD::FRINT, MVT::f64, Legal);
   }
 
SDValue LoongArchTargetLowering::LowerOperation(SDValue Op,
   case ISD::EH_DWARF_CFA:
     return lowerEH_DWARF_CFA(Op, DAG);
   case ISD::GlobalAddress:
     return lowerGlobalAddress(Op, DAG);
   case ISD::GlobalTLSAddress:
     return lowerGlobalTLSAddress(Op, DAG);
   case ISD::INTRINSIC_WO_CHAIN:
     return lowerINTRINSIC_WO_CHAIN(Op, DAG);
+  case ISD::INTRINSIC_VOID:
+    return lowerINTRINSIC_VOID(Op, DAG);
   case ISD::BlockAddress:
     return lowerBlockAddress(Op, DAG);
   case ISD::JumpTable:
     return lowerJumpTable(Op, DAG);
   case ISD::SHL_PARTS:
     return lowerShiftLeftParts(Op, DAG);
   case ISD::SRA_PARTS:
     return lowerShiftRightParts(Op, DAG, true);
default:
     return SDValue(); // Don't custom lower most intrinsics.
   case Intrinsic::thread_pointer: {
     EVT PtrVT = getPointerTy(DAG.getDataLayout());
     return DAG.getRegister(LoongArch::R2, PtrVT);
   }
   }
 }
 
+SDValue LoongArchTargetLowering::lowerINTRINSIC_VOID(SDValue Op,
+                                                     SelectionDAG &DAG) const {
+  SDLoc DL(Op);
+  MVT GRLenVT = Subtarget.getGRLenVT();
+
+  switch (Op.getConstantOperandVal(1)) {
+  default:
+    // TODO: Add more Intrinsics.
+    return SDValue();
+  case Intrinsic::loongarch_dbar: {
+    SDValue Op0 = Op.getOperand(0);
+    SDValue Op2 = Op.getOperand(2);
+    if (!isa<ConstantSDNode>(Op2)) {
+      DAG.getContext()->emitError("argument to '__builtin_loongarch_dbar' must "
+                                  "be a constant integer");
+      return Op.getOperand(0);
+    }
+    unsigned Imm = cast<ConstantSDNode>(Op2)->getZExtValue();
+    if (!isUInt<15>(Imm)) {
+      DAG.getContext()->emitError(
+          "argument to '__builtin_loongarch_dbar' out of range");
+      return Op0;
+    }
+
+    if (GRLenVT == MVT::i32)
+      return Op;
+    return DAG.getNode(LoongArchISD::DBAR, DL, MVT::Other, Op0,
+                       DAG.getConstant(Imm, DL, GRLenVT));
+  }
+  }
+}
+
 SDValue LoongArchTargetLowering::lowerShiftLeftParts(SDValue Op,
                                                      SelectionDAG &DAG) const {
   SDLoc DL(Op);
   SDValue Lo = Op.getOperand(0);
   SDValue Hi = Op.getOperand(1);
   SDValue Shamt = Op.getOperand(2);
   EVT VT = Lo.getValueType();
 
case LoongArchISD::node:                                                     \
     NODE_NAME_CASE(REVB_2H)
     NODE_NAME_CASE(REVB_2W)
     NODE_NAME_CASE(BITREV_4B)
     NODE_NAME_CASE(BITREV_W)
     NODE_NAME_CASE(ROTR_W)
     NODE_NAME_CASE(ROTL_W)
     NODE_NAME_CASE(CLZ_W)
     NODE_NAME_CASE(CTZ_W)
+    NODE_NAME_CASE(DBAR)
   }
 #undef NODE_NAME_CASE
   return nullptr;
 }
 
 //===----------------------------------------------------------------------===//
 //                     Calling Convention Implementation
 //===----------------------------------------------------------------------===//

llvm/lib/Target/LoongArch/LoongArchInstrInfo.td

def SDT_LoongArchBStrIns: SDTypeProfile<1, 4, [
   SDTCisInt<0>, SDTCisSameAs<0, 1>, SDTCisSameAs<0, 2>, SDTCisInt<3>,
   SDTCisSameAs<3, 4>
 ]>;
 
 def SDT_LoongArchBStrPick: SDTypeProfile<1, 3, [
   SDTCisInt<0>, SDTCisSameAs<0, 1>, SDTCisInt<2>, SDTCisSameAs<2, 3>
 ]>;
 
+def SDT_LoongArchDBAR : SDTypeProfile<0, 1, [SDTCisVT<0, GRLenVT>]>;
+
 // TODO: Add LoongArch specific DAG Nodes
 // Target-independent nodes, but with target-specific formats.
 def callseq_start : SDNode<"ISD::CALLSEQ_START", SDT_CallSeqStart,
                            [SDNPHasChain, SDNPOutGlue]>;
 def callseq_end : SDNode<"ISD::CALLSEQ_END", SDT_CallSeqEnd,
                          [SDNPHasChain, SDNPOptInGlue, SDNPOutGlue]>;
 
 // Target-dependent nodes.

 def loongarch_bstrpick
     : SDNode<"LoongArchISD::BSTRPICK", SDT_LoongArchBStrPick>;
 def loongarch_revb_2h : SDNode<"LoongArchISD::REVB_2H", SDTUnaryOp>;
 def loongarch_revb_2w : SDNode<"LoongArchISD::REVB_2W", SDTUnaryOp>;
 def loongarch_bitrev_4b : SDNode<"LoongArchISD::BITREV_4B", SDTUnaryOp>;
 def loongarch_bitrev_w : SDNode<"LoongArchISD::BITREV_W", SDTUnaryOp>;
 def loongarch_clzw : SDNode<"LoongArchISD::CLZ_W", SDTIntBitCountUnaryOp>;
 def loongarch_ctzw : SDNode<"LoongArchISD::CTZ_W", SDTIntBitCountUnaryOp>;
+def loongarch_dbar : SDNode<"LoongArchISD::DBAR", SDT_LoongArchDBAR,
+                             [SDNPHasChain, SDNPSideEffect]>;
 
 //===----------------------------------------------------------------------===//
 // Operand and SDNode transformation definitions.
 //===----------------------------------------------------------------------===//
 
 class ImmAsmOperand<string prefix, int width, string suffix>
     : AsmOperandClass {
   let Name = prefix # "Imm" # width # suffix;

 def uimm12_ori : UImm12Operand {
   let ParserMatchClass = UImmAsmOperand<12, "ori">;
 }
 
 def uimm14 : Operand<GRLenVT> {
   let ParserMatchClass = UImmAsmOperand<14>;
 }
 
-def uimm15 : Operand<GRLenVT> {
+def uimm15 : Operand<GRLenVT>,
+             ImmLeaf <GRLenVT, [{return isUInt<15>(Imm);}]> {
   let ParserMatchClass = UImmAsmOperand<15>;
 }
 
 class SImm12Operand : Operand<GRLenVT>,
                       ImmLeaf <GRLenVT, [{return isInt<12>(Imm);}]> {
   let DecoderMethod = "decodeSImmOperand<12>";
 }
 

 def : Pat<(atomic_load_and_32 GPR:$addr, GPR:$incr),
           (PseudoAtomicLoadAnd32 GPR:$incr, GPR:$addr)>;
 def : Pat<(atomic_load_or_32 GPR:$addr, GPR:$incr),
           (PseudoAtomicLoadOr32 GPR:$incr, GPR:$addr)>;
 def : Pat<(atomic_load_xor_32 GPR:$addr, GPR:$incr),
           (PseudoAtomicLoadXor32 GPR:$incr, GPR:$addr)>;
 } // Predicates = [IsLA32]
 
+/// Intrinsics
+
+let Predicates = [IsLA32] in {
+def : Pat<(int_loongarch_dbar uimm15:$imm15), (DBAR uimm15:$imm15)>;
+} // Predicates = [IsLA32]
+
+let Predicates = [IsLA64] in {
+def : Pat<(loongarch_dbar uimm15:$imm15), (DBAR uimm15:$imm15)>;
+} // Predicates = [IsLA64]
+
 /// Other pseudo-instructions
 
 // Pessimistically assume the stack pointer will be clobbered
 let Defs = [R3], Uses = [R3] in {
 def ADJCALLSTACKDOWN : Pseudo<(outs), (ins i32imm:$amt1, i32imm:$amt2),
                               [(callseq_start timm:$amt1, timm:$amt2)]>;
 def ADJCALLSTACKUP   : Pseudo<(outs), (ins i32imm:$amt1, i32imm:$amt2),
                               [(callseq_end timm:$amt1, timm:$amt2)]>;

llvm/test/CodeGen/LoongArch/intrinsic-error.ll

+; RUN: not llc --mtriple=loongarch32 --disable-verify < %s 2>&1 | FileCheck %s
+; RUN: not llc --mtriple=loongarch64 --disable-verify < %s 2>&1 | FileCheck %s
+
+define void @dbar_not_constant(i32 %x) nounwind {
+; CHECK: argument to '__builtin_loongarch_dbar' must be a constant integer
+entry:
+  call void @llvm.loongarch.dbar(i32 %x)
+  ret void
+}
+
+define void @dbar_imm_out_of_range() nounwind {
+; CHECK: argument to '__builtin_loongarch_dbar' out of range
+entry:
+  call void @llvm.loongarch.dbar(i32 32769)
+  ret void
+}
+
+declare void @llvm.loongarch.dbar(i32)

llvm/test/CodeGen/LoongArch/intrinsic.ll

+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc --mtriple=loongarch32 < %s | FileCheck %s
+; RUN: llc --mtriple=loongarch64 < %s | FileCheck %s
+
+declare void @llvm.loongarch.dbar(i32)
+
+define void @foo() nounwind {
+; CHECK-LABEL: foo:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    dbar 0
+; CHECK-NEXT:    ret
+entry:
+  call void @llvm.loongarch.dbar(i32 0)
+  ret void
+}