[flang] Support -mabi=vec-extabi and -mabi=vec-default on AIX (llvm#113215)

This option is to enable the AIX extended and default vector ABIs.

Author: kkwli

clang/include/clang/Driver/Options.td

@@ -4678,7 +4678,8 @@ def malign_loops_EQ : Joined<["-"], "malign-loops=">, Group<clang_ignored_m_Grou
 def malign_jumps_EQ : Joined<["-"], "malign-jumps=">, Group<clang_ignored_m_Group>;
 
 let Flags = [TargetSpecific] in {
-def mabi_EQ : Joined<["-"], "mabi=">, Group<m_Group>;
+def mabi_EQ : Joined<["-"], "mabi=">, Group<m_Group>,
+  Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>;
 def malign_branch_EQ : CommaJoined<["-"], "malign-branch=">, Group<m_Group>,
   HelpText<"Specify types of branches to align">;
 def malign_branch_boundary_EQ : Joined<["-"], "malign-branch-boundary=">, Group<m_Group>,
@@ -7363,6 +7364,7 @@ def mabi_EQ_ieeelongdouble : Flag<["-"], "mabi=ieeelongdouble">,
   HelpText<"Use IEEE 754 quadruple-precision for long double">,
   MarshallingInfoFlag<LangOpts<"PPCIEEELongDouble">>;
 def mabi_EQ_vec_extabi : Flag<["-"], "mabi=vec-extabi">,
+  Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
   HelpText<"Enable the extended Altivec ABI on AIX. Use volatile and nonvolatile vector registers">,
   MarshallingInfoFlag<LangOpts<"EnableAIXExtendedAltivecABI">>;
 def mfloat_abi : Separate<["-"], "mfloat-abi">,

clang/lib/Driver/ToolChains/Flang.cpp

@@ -203,6 +203,32 @@ void Flang::AddAArch64TargetArgs(const ArgList &Args,
   }
 }
 
+void Flang::AddPPCTargetArgs(const ArgList &Args,
+                             ArgStringList &CmdArgs) const {
+  const Driver &D = getToolChain().getDriver();
+  bool VecExtabi = false;
+
+  if (const Arg *A = Args.getLastArg(options::OPT_mabi_EQ)) {
+    StringRef V = A->getValue();
+    if (V == "vec-extabi")
+      VecExtabi = true;
+    else if (V == "vec-default")
+      VecExtabi = false;
+    else
+      D.Diag(diag::err_drv_unsupported_option_argument)
+          << A->getSpelling() << V;
+  }
+
+  const llvm::Triple &T = getToolChain().getTriple();
+  if (VecExtabi) {
+    if (!T.isOSAIX()) {
+      D.Diag(diag::err_drv_unsupported_opt_for_target)
+          << "-mabi=vec-extabi" << T.str();
+    }
+    CmdArgs.push_back("-mabi=vec-extabi");
+  }
+}
+
 void Flang::AddRISCVTargetArgs(const ArgList &Args,
                                ArgStringList &CmdArgs) const {
   const llvm::Triple &Triple = getToolChain().getTriple();
@@ -383,6 +409,11 @@ void Flang::addTargetOptions(const ArgList &Args,
     getTargetFeatures(D, Triple, Args, CmdArgs, /*ForAs*/ false);
     AddX86_64TargetArgs(Args, CmdArgs);
     break;
+  case llvm::Triple::ppc:
+  case llvm::Triple::ppc64:
+  case llvm::Triple::ppc64le:
+    AddPPCTargetArgs(Args, CmdArgs);
+    break;
   }
 
   if (Arg *A = Args.getLastArg(options::OPT_fveclib)) {

clang/lib/Driver/ToolChains/Flang.h

@@ -84,6 +84,13 @@ class LLVM_LIBRARY_VISIBILITY Flang : public Tool {
   void AddX86_64TargetArgs(const llvm::opt::ArgList &Args,
                            llvm::opt::ArgStringList &CmdArgs) const;
 
+  /// Add specific options for PPC target.
+  ///
+  /// \param [in] Args The list of input driver arguments
+  /// \param [out] CmdArgs The list of output command arguments
+  void AddPPCTargetArgs(const llvm::opt::ArgList &Args,
+                        llvm::opt::ArgStringList &CmdArgs) const;
+
   /// Extract offload options from the driver arguments and add them to
   /// the command arguments.
   /// \param [in] C The current compilation for the driver invocation

flang/include/flang/Frontend/TargetOptions.h

@@ -44,6 +44,9 @@ class TargetOptions {
 
   /// The integer KINDs disabled for this target
   std::vector<int> disabledIntegerKinds;
+
+  /// Extended Altivec ABI on AIX
+  bool EnableAIXExtendedAltivecABI;
 };
 
 } // end namespace Fortran::frontend

flang/lib/Frontend/CompilerInstance.cpp

@@ -313,7 +313,6 @@ bool CompilerInstance::setUpTargetMachine() {
         << error;
     return false;
   }
-
   // Create `TargetMachine`
   const auto &CGOpts = getInvocation().getCodeGenOpts();
   std::optional<llvm::CodeGenOptLevel> OptLevelOrNone =
@@ -322,9 +321,13 @@ bool CompilerInstance::setUpTargetMachine() {
   llvm::CodeGenOptLevel OptLevel = *OptLevelOrNone;
   std::string featuresStr = getTargetFeatures();
   std::optional<llvm::CodeModel::Model> cm = getCodeModel(CGOpts.CodeModel);
+
+  llvm::TargetOptions tOpts = llvm::TargetOptions();
+  tOpts.EnableAIXExtendedAltivecABI = targetOpts.EnableAIXExtendedAltivecABI;
+
   targetMachine.reset(theTarget->createTargetMachine(
       theTriple, /*CPU=*/targetOpts.cpu,
-      /*Features=*/featuresStr, llvm::TargetOptions(),
+      /*Features=*/featuresStr, /*Options=*/tOpts,
       /*Reloc::Model=*/CGOpts.getRelocationModel(),
       /*CodeModel::Model=*/cm, OptLevel));
   assert(targetMachine && "Failed to create TargetMachine");

flang/lib/Frontend/CompilerInvocation.cpp

@@ -457,6 +457,16 @@ static void parseTargetArgs(TargetOptions &opts, llvm::opt::ArgList &args) {
 
   if (args.hasArg(clang::driver::options::OPT_fdisable_integer_16))
     opts.disabledIntegerKinds.push_back(16);
+
+  if (const llvm::opt::Arg *a =
+          args.getLastArg(clang::driver::options::OPT_mabi_EQ)) {
+    llvm::StringRef V = a->getValue();
+    if (V == "vec-extabi") {
+      opts.EnableAIXExtendedAltivecABI = true;
+    } else if (V == "vec-default") {
+      opts.EnableAIXExtendedAltivecABI = false;
+    }
+  }
 }
 // Tweak the frontend configuration based on the frontend action
 static void setUpFrontendBasedOnAction(FrontendOptions &opts) {

flang/test/Driver/mabi.f90

@@ -0,0 +1,17 @@
+! RUN: not %flang -### -c --target=powerpc64le-unknown-linux -mabi=vec-extabi %s 2>&1 | FileCheck --check-prefix=INVALID1 %s
+! RUN: not %flang -### -c --target=x86_64-unknown-linux -mabi=vec-extabi %s 2>&1 | FileCheck --check-prefix=INVALID2 %s
+! RUN: not %flang -### -c --target=powerpc-unknown-aix -mabi=abc %s 2>&1 | FileCheck --check-prefix=INVALID3 %s
+! RUN: %flang -### -c -target powerpc-unknown-aix %s 2>&1 | FileCheck --implicit-check-not=vec-extabi %s
+! RUN: %flang -### -c -target powerpc-unknown-aix -mabi=vec-default %s 2>&1 | FileCheck --implicit-check-not=vec-extabi %s
+! RUN: %flang -### -c -target powerpc-unknown-aix -mabi=vec-extabi %s 2>&1 | FileCheck --check-prefix=EXTABI %s
+
+! REQUIRES: target=powerpc{{.*}}
+
+! INVALID1: error: unsupported option '-mabi=vec-extabi' for target '{{.*}}'
+! INVALID2: error: unsupported option '-mabi=' for target '{{.*}}'
+! INVALID3: error: unsupported argument 'abc' to option '-mabi='
+
+! EXTABI: "-fc1"
+! EXTABI-SAME: "-mabi=vec-extabi"
+
+