[AArch64] ACLE feature macro for Armv8.8-A MOPS

[tyb0807]

Summary

This introduces the new __ARM_FEATURE_MOPS ACLE feature test macro,
which signals the availability of the new Armv8.8-A/Armv9.3-A
instructions for standardising memcpy, memset and memmove operations.

[ktkachov]

I think the most important use of the __ARM_FEATURE_MOPS is to check whether it's safe to use the new intrinsics, so it should only be defined by the compiler once it supports the intrinsics proposed in https://github.com/ARM-software/acle/pull/38/files

[chill]

clang/lib/Basic/Targets/AArch64.cpp

666

So, this is enabled by default (as in "is mandatory part") of 8.8-a and 9.3-a? Why don't we handle it like other extensions in AArch64TargetParser.def like https://reviews.llvm.org/D115694#inline-1110596

[tyb0807]

This is superseded by https://reviews.llvm.org/D118199. Comments have been addressed in the new patch. I should have commandeered this patch instead (did not know about this, sorry...).

clang/lib/Basic/Targets/AArch64.h

class LLVM_LIBRARY_VISIBILITY AArch64TargetInfo : public TargetInfo {
   bool HasSVE2AES;
   bool HasSVE2SHA3;
   bool HasSVE2SM4;
   bool HasSVE2BitPerm;
   bool HasMatmulFP64;
   bool HasMatmulFP32;
   bool HasLSE;
   bool HasFlagM;
+  bool HasMOPS;
 
   llvm::AArch64::ArchKind ArchKind;
 
   static const Builtin::Info BuiltinInfo[];
 
   std::string ABI;
   StringRef getArchProfile() const;
 

clang/lib/Basic/Targets/AArch64.cpp

if (Opts.BranchTargetEnforcement)
     Builder.defineMacro("__ARM_FEATURE_BTI_DEFAULT", "1");
 
   if (HasLS64)
     Builder.defineMacro("__ARM_FEATURE_LS64", "1");
 
   if (HasRandGen)
     Builder.defineMacro("__ARM_FEATURE_RNG", "1");
 
+  if (HasMOPS)
+    Builder.defineMacro("__ARM_FEATURE_MOPS", "1");
+
   switch (ArchKind) {
   default:
     break;
   case llvm::AArch64::ArchKind::ARMV8_1A:
     getTargetDefinesARMV81A(Opts, Builder);
     break;
   case llvm::AArch64::ArchKind::ARMV8_2A:
     getTargetDefinesARMV82A(Opts, Builder);
for (const auto &Feature : Features) {
     if (Feature == "+ls64")
       HasLS64 = true;
     if (Feature == "+rand")
       HasRandGen = true;
     if (Feature == "+flagm")
       HasFlagM = true;
   }
 
+  HasMOPS |= ArchKind == llvm::AArch64::ArchKind::ARMV8_8A ||
+             ArchKind == llvm::AArch64::ArchKind::ARMV9_3A;
+
+  // Check features that are manually disabled by command line options.
+  // This needs to be checked after architecture-related features are handled,
+  // making sure they are properly disabled when required.
+  for (const auto &Feature : Features) {
+    if (Feature == "-mops")
+      HasMOPS = false;
+  }
+
   setDataLayout();
 
   return true;
 }
 
 TargetInfo::CallingConvCheckResult
 AArch64TargetInfo::checkCallingConvention(CallingConv CC) const {
   switch (CC) {

clang/test/Preprocessor/aarch64-target-features.c

 // CHECK-NO-SVE-VECTOR-BITS-NOT: __ARM_FEATURE_SVE_VECTOR_OPERATORS
 
 // ================== Check Largse System Extensions (LSE)
 // RUN: %clang -target aarch64-none-linux-gnu -march=armv8-a+lse -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-LSE %s
 // RUN: %clang -target arm64-none-linux-gnu -march=armv8-a+lse -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-LSE %s
 // RUN: %clang -target aarch64-none-linux-gnu -march=armv8.1-a -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-LSE %s
 // RUN: %clang -target arm64-none-linux-gnu -march=armv8.1-a -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-LSE %s
 // CHECK-LSE: __ARM_FEATURE_ATOMICS 1
+
+// ================== Check Armv8.8-A/Armv9.3-A memcpy and memset acceleration instructions (MOPS)
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv8-a+mops -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-MOPS %s
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv8.8-a -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-MOPS %s
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv8.8-a+nomops -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-NOMOPS %s
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv9-a+mops -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-MOPS %s
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv9.3-a -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-MOPS %s
+// RUN: %clang -target aarch64-arm-none-eabi -march=armv9.3-a+nomops -x c -E -dM %s -o - | FileCheck --check-prefix=CHECK-NOMOPS %s
+// CHECK-MOPS: __ARM_FEATURE_MOPS 1
+// CHECK-NOMOPS-NOT: __ARM_FEATURE_MOPS 1

llvm/include/llvm/Support/AArch64TargetParser.h

 //===-- AArch64TargetParser - Parser for AArch64 features -------*- 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 implements a target parser to recognise AArch64 hardware features

 namespace llvm {
 
 class Triple;
 
 namespace AArch64 {
 
 // Arch extension modifiers for CPUs.
 enum ArchExtKind : uint64_t {
   AEK_INVALID =     0,
   AEK_NONE =        1,
   AEK_CRC =         1 << 1,
   AEK_CRYPTO =      1 << 2,
   AEK_FP =          1 << 3,
   AEK_SIMD =        1 << 4,
   AEK_FP16 =        1 << 5,
   AEK_PROFILE =     1 << 6,
   AEK_RAS =         1 << 7,
enum ArchExtKind : uint64_t {
   AEK_SSBS =        1 << 20,
   AEK_SB =          1 << 21,
   AEK_PREDRES =     1 << 22,
   AEK_SVE2 =        1 << 23,
   AEK_SVE2AES =     1 << 24,
   AEK_SVE2SM4 =     1 << 25,
   AEK_SVE2SHA3 =    1 << 26,
   AEK_SVE2BITPERM = 1 << 27,
   AEK_TME =         1 << 28,
   AEK_BF16 =        1 << 29,
   AEK_I8MM =        1 << 30,
   AEK_F32MM =       1ULL << 31,
   AEK_F64MM =       1ULL << 32,
   AEK_LS64 =        1ULL << 33,
   AEK_BRBE =        1ULL << 34,
   AEK_PAUTH =       1ULL << 35,
   AEK_FLAGM =       1ULL << 36,
   AEK_SME =         1ULL << 37,
   AEK_SMEF64 =      1ULL << 38,
   AEK_SMEI64 =      1ULL << 39,
+  AEK_MOPS =        1ULL << 40,
 };
 
 enum class ArchKind {
 #define AARCH64_ARCH(NAME, ID, CPU_ATTR, SUB_ARCH, ARCH_ATTR, ARCH_FPU, ARCH_BASE_EXT) ID,
 #include "AArch64TargetParser.def"
 };
 
 const ARM::ArchNames<ArchKind> AArch64ARCHNames[] = {