[COFF, ARM64] Add MS builtins __dmb, __dsb, __isb

[mstorsjo]

Summary

This is an update to D36111 by @mgrang, taking over finishing of this patch. Compared to his version, this makes the intrinsics conditional to ALL_MS_LANGUAGES.

[mgrang]

LGTM.

[compnerd]

Don't you need a change to the intrinsics to actually map the builtin?

[mstorsjo]

In D38821#895527, @compnerd wrote:

Don't you need a change to the intrinsics to actually map the builtin?

Apparently, this change is all that's needed since the tests pass. I can of course try to look closer and see what actually makes it work.

[mstorsjo]

In D38821#895527, @compnerd wrote:

Don't you need a change to the intrinsics to actually map the builtin?

This seems to be automatically mapped via this piece of code in CGBuiltin.cpp:

// See if we have a target specific intrinsic.
const char *Name = getContext().BuiltinInfo.getName(BuiltinID);
Intrinsic::ID IntrinsicID = Intrinsic::not_intrinsic;
StringRef Prefix =
    llvm::Triple::getArchTypePrefix(getTarget().getTriple().getArch());
if (!Prefix.empty()) {
  IntrinsicID = Intrinsic::getIntrinsicForGCCBuiltin(Prefix.data(), Name);
  // NOTE we dont need to perform a compatibility flag check here since the
  // intrinsics are declared in Builtins*.def via LANGBUILTIN which filter the
  // MS builtins via ALL_MS_LANGUAGES and are filtered earlier.
  if (IntrinsicID == Intrinsic::not_intrinsic)
    IntrinsicID = Intrinsic::getIntrinsicForMSBuiltin(Prefix.data(), Name);
}

And these target specific intrinsics are already hooked up on the LLVM side in SVN r310502.

include/clang/Basic/BuiltinsAArch64.def

 //==- BuiltinsAArch64.def - AArch64 Builtin function database ----*- C++ -*-==//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines the AArch64-specific builtin function database.  Users of
 // this file must define the BUILTIN macro to make use of this information.
 //
 //===----------------------------------------------------------------------===//
 
 // The format of this database matches clang/Basic/Builtins.def.
 
+#if defined(BUILTIN) && !defined(LANGBUILTIN)
+#   define LANGBUILTIN(ID, TYPE, ATTRS, BUILTIN_LANG) BUILTIN(ID, TYPE, ATTRS)
+#endif
+
 // In libgcc
 BUILTIN(__clear_cache, "vv*v*", "i")
 
 BUILTIN(__builtin_arm_ldrex, "v.", "t")
 BUILTIN(__builtin_arm_ldaex, "v.", "t")
 BUILTIN(__builtin_arm_strex, "i.", "t")
 BUILTIN(__builtin_arm_stlex, "i.", "t")
 BUILTIN(__builtin_arm_clrex, "v", "")

 // System Registers
 BUILTIN(__builtin_arm_rsr, "UicC*", "nc")
 BUILTIN(__builtin_arm_rsr64, "LUicC*", "nc")
 BUILTIN(__builtin_arm_rsrp, "v*cC*", "nc")
 BUILTIN(__builtin_arm_wsr, "vcC*Ui", "nc")
 BUILTIN(__builtin_arm_wsr64, "vcC*LUi", "nc")
 BUILTIN(__builtin_arm_wsrp, "vcC*vC*", "nc")
 
+LANGBUILTIN(__dmb, "vUi", "nc", ALL_MS_LANGUAGES)
+LANGBUILTIN(__dsb, "vUi", "nc", ALL_MS_LANGUAGES)
+LANGBUILTIN(__isb, "vUi", "nc", ALL_MS_LANGUAGES)
+
 #undef BUILTIN
+#undef LANGBUILTIN

lib/Basic/Targets/AArch64.cpp

 
 const Builtin::Info AArch64TargetInfo::BuiltinInfo[] = {
 #define BUILTIN(ID, TYPE, ATTRS)                                               \
    {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr},
 #include "clang/Basic/BuiltinsNEON.def"
 
 #define BUILTIN(ID, TYPE, ATTRS)                                               \
    {#ID, TYPE, ATTRS, nullptr, ALL_LANGUAGES, nullptr},
+#define LANGBUILTIN(ID, TYPE, ATTRS, LANG)                                     \
+  {#ID, TYPE, ATTRS, nullptr, LANG, nullptr},
 #include "clang/Basic/BuiltinsAArch64.def"
 };
 
 AArch64TargetInfo::AArch64TargetInfo(const llvm::Triple &Triple,
                                      const TargetOptions &Opts)
     : TargetInfo(Triple), ABI("aapcs") {
   if (getTriple().getOS() == llvm::Triple::NetBSD ||
       getTriple().getOS() == llvm::Triple::OpenBSD) {

test/CodeGen/arm64-microsoft-intrinsics.c

+// RUN: %clang_cc1 -triple arm64-windows -fms-compatibility -emit-llvm -o - %s \
+// RUN:    | FileCheck %s -check-prefix CHECK-MSVC
+
+// RUN: not %clang_cc1 -triple arm64-linux -Werror -S -o /dev/null %s 2>&1 \
+// RUN:    | FileCheck %s -check-prefix CHECK-LINUX
+
+void check__dmb(void) {
+  __dmb(0);
+}
+
+// CHECK-MSVC: @llvm.aarch64.dmb(i32 0)
+// CHECK-LINUX: error: implicit declaration of function '__dmb'
+
+void check__dsb(void) {
+  __dsb(0);
+}
+
+// CHECK-MSVC: @llvm.aarch64.dsb(i32 0)
+// CHECK-LINUX: error: implicit declaration of function '__dsb'
+
+void check__isb(void) {
+  __isb(0);
+}
+
+// CHECK-MSVC: @llvm.aarch64.isb(i32 0)
+// CHECK-LINUX: error: implicit declaration of function '__isb'