[AArch64] ACLE: Fix issue for mismatching enum types with builtins.

[sdesmalen]

Summary

This patch fixes an issue with the SVE prefetch and qinc/qdec intrinsics
that take an enum argument, but where the builtin prototype encodes
these as int. Some code in SemaDecl found the mismatch and chose
to forget about the builtin altogether, which meant that any future
code using that builtin would fail. The code that forgets about the
builtin was actually obsolete after D77491 and should have been removed.
This patch now removes that code.

This patch also fixes another issue with the SVE prefetch intrinsic
when built with C++, where the builtin didn't accept the correct
pointer type, which should be const void *.

[sdesmalen]

The fact that Clang chooses to (explicitly) forget about a builtin in SemaDecl.cpp was quite puzzling to me. Maybe that just shows that I don't fully understand how the builtin mechanism is supposed to work.
@rsmith and @tambre, git history showed me you have more experience in this area and touched some of that code before, so hopefully you can give me some good feedback!

[tambre]

In D100046#2674311, @sdesmalen wrote:

The fact that Clang chooses to (explicitly) forget about a builtin in SemaDecl.cpp was quite puzzling to me. Maybe that just shows that I don't fully understand how the builtin mechanism is supposed to work.
@rsmith and @tambre, git history showed me you have more experience in this area and touched some of that code before, so hopefully you can give me some good feedback!

Sorry for the delay, I'm lately quite busy during the week.
I'll have a look over the weekend.

[tambre]

clang/lib/Sema/SemaDecl.cpp

10968–10969

This whole block is unnecessary since D77491 and should've been removed, but seems I missed it. Reverting/forgetting builtins was problematic and the attribute-based approach solved those deficiencies.

Delete this whole block and also remove forgetBuiltin(). The builtin-related code in ActOnFunctionDeclarator() handles everything necessary. No tests break and the SVE ones will pass. :)

[sdesmalen]

Removed forgetBuiltin and the code using it.

[sdesmalen]

Thanks for taking time from your weekend to look into this @tambre, much appreciated!

clang/lib/Sema/SemaDecl.cpp

10968–10969

Awesome! I had indeed noticed commenting it out didn't fail any tests and wondered if removing it entirely was the way to go. Good to hear you confirming that!

[tambre]

Thanks, LGTM! Probably worth mentioning what I had in my comment in the commit message.

[tambre]

Summary also looks good. 👍
You probably don't need to wait for more approvals.

clang/include/clang/Basic/Builtins.h

public:
 
   /// Return true if this builtin has a result or any arguments which are
   /// reference types.
   bool hasReferenceArgsOrResult(unsigned ID) const {
     return strchr(getRecord(ID).Type, '&') != nullptr ||
            strchr(getRecord(ID).Type, 'A') != nullptr;
   }
 
-  /// Completely forget that the given ID was ever considered a builtin,
-  /// e.g., because the user provided a conflicting signature.
-  void forgetBuiltin(unsigned ID, IdentifierTable &Table);
-
   /// If this is a library function that comes from a specific
   /// header, retrieve that header name.
   const char *getHeaderName(unsigned ID) const {
     return getRecord(ID).HeaderName;
   }
 
   /// Determine whether this builtin is like printf in its
   /// formatting rules and, if so, set the index to the format string

clang/include/clang/Basic/arm_sve.td

let ArchGuard = "defined(__ARM_FEATURE_SVE_BF16)" in {
   def SVSTNT1_BF      : MInst<"svstnt1[_{d}]",      "vPpd",  "b", [IsStore], MemEltTyDefault, "aarch64_sve_stnt1">;
   def SVSTNT1_VNUM_BF : MInst<"svstnt1_vnum[_{d}]", "vPpld", "b", [IsStore], MemEltTyDefault, "aarch64_sve_stnt1">;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // Prefetches
 
 // Prefetch (Scalar base)
-def SVPRFB : MInst<"svprfb", "vPcJ", "c", [IsPrefetch], MemEltTyInt8,  "aarch64_sve_prf">;
-def SVPRFH : MInst<"svprfh", "vPcJ", "s", [IsPrefetch], MemEltTyInt16, "aarch64_sve_prf">;
-def SVPRFW : MInst<"svprfw", "vPcJ", "i", [IsPrefetch], MemEltTyInt32, "aarch64_sve_prf">;
-def SVPRFD : MInst<"svprfd", "vPcJ", "l", [IsPrefetch], MemEltTyInt64, "aarch64_sve_prf">;
+def SVPRFB : MInst<"svprfb", "vPQJ", "c", [IsPrefetch], MemEltTyInt8,  "aarch64_sve_prf">;
+def SVPRFH : MInst<"svprfh", "vPQJ", "s", [IsPrefetch], MemEltTyInt16, "aarch64_sve_prf">;
+def SVPRFW : MInst<"svprfw", "vPQJ", "i", [IsPrefetch], MemEltTyInt32, "aarch64_sve_prf">;
+def SVPRFD : MInst<"svprfd", "vPQJ", "l", [IsPrefetch], MemEltTyInt64, "aarch64_sve_prf">;
 
 // Prefetch (Scalar base, VL displacement)
-def SVPRFB_VNUM : MInst<"svprfb_vnum", "vPclJ", "c", [IsPrefetch], MemEltTyInt8,  "aarch64_sve_prf">;
-def SVPRFH_VNUM : MInst<"svprfh_vnum", "vPclJ", "s", [IsPrefetch], MemEltTyInt16, "aarch64_sve_prf">;
-def SVPRFW_VNUM : MInst<"svprfw_vnum", "vPclJ", "i", [IsPrefetch], MemEltTyInt32, "aarch64_sve_prf">;
-def SVPRFD_VNUM : MInst<"svprfd_vnum", "vPclJ", "l", [IsPrefetch], MemEltTyInt64, "aarch64_sve_prf">;
+def SVPRFB_VNUM : MInst<"svprfb_vnum", "vPQlJ", "c", [IsPrefetch], MemEltTyInt8,  "aarch64_sve_prf">;
+def SVPRFH_VNUM : MInst<"svprfh_vnum", "vPQlJ", "s", [IsPrefetch], MemEltTyInt16, "aarch64_sve_prf">;
+def SVPRFW_VNUM : MInst<"svprfw_vnum", "vPQlJ", "i", [IsPrefetch], MemEltTyInt32, "aarch64_sve_prf">;
+def SVPRFD_VNUM : MInst<"svprfd_vnum", "vPQlJ", "l", [IsPrefetch], MemEltTyInt64, "aarch64_sve_prf">;
 
 // Prefetch (Vector bases)
 def SVPRFB_GATHER_BASES : MInst<"svprfb_gather[_{2}base]", "vPdJ", "UiUl", [IsGatherPrefetch], MemEltTyInt8,  "aarch64_sve_prfb_gather_scalar_offset">;
 def SVPRFH_GATHER_BASES : MInst<"svprfh_gather[_{2}base]", "vPdJ", "UiUl", [IsGatherPrefetch], MemEltTyInt16, "aarch64_sve_prfh_gather_scalar_offset">;
 def SVPRFW_GATHER_BASES : MInst<"svprfw_gather[_{2}base]", "vPdJ", "UiUl", [IsGatherPrefetch], MemEltTyInt32, "aarch64_sve_prfw_gather_scalar_offset">;
 def SVPRFD_GATHER_BASES : MInst<"svprfd_gather[_{2}base]", "vPdJ", "UiUl", [IsGatherPrefetch], MemEltTyInt64, "aarch64_sve_prfd_gather_scalar_offset">;
 
 // Prefetch (Scalar base, Vector offsets)

clang/lib/Basic/Builtins.cpp

if (builtinIsSupported(TSRecords[i], LangOpts))
       Table.get(TSRecords[i].Name).setBuiltinID(i + Builtin::FirstTSBuiltin);
 
   // Step #3: Register target-specific builtins for AuxTarget.
   for (unsigned i = 0, e = AuxTSRecords.size(); i != e; ++i)
     Table.get(AuxTSRecords[i].Name)
         .setBuiltinID(i + Builtin::FirstTSBuiltin + TSRecords.size());
 }
 
-void Builtin::Context::forgetBuiltin(unsigned ID, IdentifierTable &Table) {
-  Table.get(getRecord(ID).Name).setBuiltinID(0);
-}
-
 unsigned Builtin::Context::getRequiredVectorWidth(unsigned ID) const {
   const char *WidthPos = ::strchr(getRecord(ID).Attributes, 'V');
   if (!WidthPos)
     return 0;
 
   ++WidthPos;
   assert(*WidthPos == ':' &&
          "Vector width specifier must be followed by a ':'");

clang/lib/Sema/SemaDecl.cpp

if (NewFD->getLiteralIdentifier() &&
       return Redeclaration;
     }
 
     // In C++, check default arguments now that we have merged decls. Unless
     // the lexical context is the class, because in this case this is done
     // during delayed parsing anyway.
     if (!CurContext->isRecord())
       CheckCXXDefaultArguments(NewFD);
 
-    // If this function declares a builtin function, check the type of this
-    // declaration against the expected type for the builtin.
-    if (unsigned BuiltinID = NewFD->getBuiltinID()) {
-      ASTContext::GetBuiltinTypeError Error;
-      LookupNecessaryTypesForBuiltin(S, BuiltinID);
-      QualType T = Context.GetBuiltinType(BuiltinID, Error);
-      // If the type of the builtin differs only in its exception
-      // specification, that's OK.
-      // FIXME: If the types do differ in this way, it would be better to
-      // retain the 'noexcept' form of the type.
-      if (!T.isNull() &&
-          !Context.hasSameFunctionTypeIgnoringExceptionSpec(T,
-                                                            NewFD->getType()))
-        // The type of this function differs from the type of the builtin,
-        // so forget about the builtin entirely.
-        Context.BuiltinInfo.forgetBuiltin(BuiltinID, Context.Idents);
-    }
-
     // If this function is declared as being extern "C", then check to see if
     // the function returns a UDT (class, struct, or union type) that is not C
     // compatible, and if it does, warn the user.
     // But, issue any diagnostic on the first declaration only.
     if (Previous.empty() && NewFD->isExternC()) {
       QualType R = NewFD->getReturnType();
       if (R->isIncompleteType() && !R->isVoidType())
         Diag(NewFD->getLocation(), diag::warn_return_value_udt_incomplete)
             << NewFD << R;

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_prfb.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_prfd.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_prfh.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_prfw.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qdecb.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qdecd.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qdech.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qdecp.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qdecw.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qincb.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qincd.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qinch.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qincp.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4

clang/test/CodeGen/aarch64-sve-intrinsics/acle_sve_qincw.c

 // REQUIRES: aarch64-registered-target
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - %s | FileCheck %s
+// RUN: %clang_cc1 -DSVE_OVERLOADED_FORMS -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -emit-llvm -o - -x c++ %s | FileCheck %s
 // RUN: %clang_cc1 -triple aarch64-none-linux-gnu -target-feature +sve -fallow-half-arguments-and-returns -S -O1 -Werror -Wall -o - %s >/dev/null
 #include <arm_sve.h>
 
 #ifdef SVE_OVERLOADED_FORMS
 // A simple used,unused... macro, long enough to represent any SVE builtin.
 #define SVE_ACLE_FUNC(A1,A2_UNUSED,A3,A4_UNUSED) A1##A3
 #else
 #define SVE_ACLE_FUNC(A1,A2,A3,A4) A1##A2##A3##A4