[Driver] Simplify handling of -mabi=vec-default -mabi=vec-extabi

And fix a minor issue that -mabi=vec-extabi -mabi=vec-default should not pass
"-bplugin_opt:-vec-extabi" to ld.

clang/include/clang/Driver/Options.td

@@ -3832,11 +3832,6 @@ def mno_prefixed: Flag<["-"], "mno-prefixed">, Group<m_ppc_Features_Group>;
 def mspe : Flag<["-"], "mspe">, Group<m_ppc_Features_Group>;
 def mno_spe : Flag<["-"], "mno-spe">, Group<m_ppc_Features_Group>;
 def mefpu2 : Flag<["-"], "mefpu2">, Group<m_ppc_Features_Group>;
-def mabi_EQ_vec_extabi : Flag<["-"], "mabi=vec-extabi">, Group<m_Group>, Flags<[CC1Option]>,
-  HelpText<"Enable the extended Altivec ABI on AIX (AIX only). Uses volatile and nonvolatile vector registers">,
-  MarshallingInfoFlag<LangOpts<"EnableAIXExtendedAltivecABI">>;
-def mabi_EQ_vec_default : Flag<["-"], "mabi=vec-default">, Group<m_Group>, Flags<[CC1Option]>,
-  HelpText<"Enable the default Altivec ABI on AIX (AIX only). Uses only volatile vector registers.">;
 def mabi_EQ_quadword_atomics : Flag<["-"], "mabi=quadword-atomics">,
   Group<m_Group>, Flags<[CC1Option]>,
   HelpText<"Enable quadword atomics ABI on AIX (AIX PPC64 only). Uses lqarx/stqcx. instructions.">,
@@ -5633,6 +5628,9 @@ def mframe_pointer_EQ : Joined<["-"], "mframe-pointer=">,
 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">,
+  HelpText<"Enable the extended Altivec ABI on AIX. Use volatile and nonvolatile vector registers">,
+  MarshallingInfoFlag<LangOpts<"EnableAIXExtendedAltivecABI">>;
 def mfloat_abi : Separate<["-"], "mfloat-abi">,
   HelpText<"The float ABI to use">,
   MarshallingInfoString<CodeGenOpts<"FloatABI">>;

clang/lib/Driver/ToolChains/Clang.cpp

@@ -1976,6 +1976,7 @@ void Clang::AddMIPSTargetArgs(const ArgList &Args,
 
 void Clang::AddPPCTargetArgs(const ArgList &Args,
                              ArgStringList &CmdArgs) const {
+  const Driver &D = getToolChain().getDriver();
   const llvm::Triple &T = getToolChain().getTriple();
   if (Args.getLastArg(options::OPT_mtune_EQ)) {
     CmdArgs.push_back("-tune-cpu");
@@ -2003,24 +2004,37 @@ void Clang::AddPPCTargetArgs(const ArgList &Args,
   }
 
   bool IEEELongDouble = getToolChain().defaultToIEEELongDouble();
+  bool VecExtabi = false;
   for (const Arg *A : Args.filtered(options::OPT_mabi_EQ)) {
     StringRef V = A->getValue();
-    if (V == "ieeelongdouble")
+    if (V == "ieeelongdouble") {
       IEEELongDouble = true;
-    else if (V == "ibmlongdouble")
+      A->claim();
+    } else if (V == "ibmlongdouble") {
       IEEELongDouble = false;
-    else if (V != "altivec")
+      A->claim();
+    } else if (V == "vec-default") {
+      VecExtabi = false;
+      A->claim();
+    } else if (V == "vec-extabi") {
+      VecExtabi = true;
+      A->claim();
+    } else if (V != "altivec")
       // The ppc64 linux abis are all "altivec" abis by default. Accept and ignore
       // the option if given as we don't have backend support for any targets
       // that don't use the altivec abi.
       ABIName = A->getValue();
   }
   if (IEEELongDouble)
     CmdArgs.push_back("-mabi=ieeelongdouble");
+  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");
+  }
 
-  ppc::FloatABI FloatABI =
-      ppc::getPPCFloatABI(getToolChain().getDriver(), Args);
-
+  ppc::FloatABI FloatABI = ppc::getPPCFloatABI(D, Args);
   if (FloatABI == ppc::FloatABI::Soft) {
     // Floating point operations and argument passing are soft.
     CmdArgs.push_back("-msoft-float");
@@ -5203,17 +5217,6 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
-  if (Arg *A = Args.getLastArg(options::OPT_mabi_EQ_vec_extabi,
-                               options::OPT_mabi_EQ_vec_default)) {
-    if (!Triple.isOSAIX())
-      D.Diag(diag::err_drv_unsupported_opt_for_target)
-          << A->getSpelling() << RawTriple.str();
-    if (A->getOption().getID() == options::OPT_mabi_EQ_vec_extabi)
-      CmdArgs.push_back("-mabi=vec-extabi");
-    else
-      CmdArgs.push_back("-mabi=vec-default");
-  }
-
   if (Arg *A = Args.getLastArg(options::OPT_mabi_EQ_quadword_atomics)) {
     if (!Triple.isOSAIX() || Triple.isPPC32())
       D.Diag(diag::err_drv_unsupported_opt_for_target)

clang/lib/Driver/ToolChains/CommonArgs.cpp

@@ -683,9 +683,16 @@ void tools::addLTOOptions(const ToolChain &ToolChain, const ArgList &Args,
       CmdArgs.push_back(
           Args.MakeArgString(Twine(PluginOptPrefix) + "-strict-dwarf=true"));
 
-    if (Args.getLastArg(options::OPT_mabi_EQ_vec_extabi))
-      CmdArgs.push_back(
-          Args.MakeArgString(Twine(PluginOptPrefix) + "-vec-extabi"));
+    for (const Arg *A : Args.filtered_reverse(options::OPT_mabi_EQ)) {
+      StringRef V = A->getValue();
+      if (V == "vec-default")
+        break;
+      if (V == "vec-extabi") {
+        CmdArgs.push_back(
+            Args.MakeArgString(Twine(PluginOptPrefix) + "-vec-extabi"));
+        break;
+      }
+    }
   }
 
   bool UseSeparateSections =

clang/lib/Frontend/CompilerInvocation.cpp

@@ -1935,16 +1935,6 @@ bool CompilerInvocation::ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args,
     }
   }
 
-  if (Arg *A =
-          Args.getLastArg(OPT_mabi_EQ_vec_default, OPT_mabi_EQ_vec_extabi)) {
-    if (!T.isOSAIX())
-      Diags.Report(diag::err_drv_unsupported_opt_for_target)
-          << A->getSpelling() << T.str();
-
-    const Option &O = A->getOption();
-    Opts.EnableAIXExtendedAltivecABI = O.matches(OPT_mabi_EQ_vec_extabi);
-  }
-
   if (Arg *A = Args.getLastArg(OPT_mabi_EQ_quadword_atomics)) {
     if (!T.isOSAIX() || T.isPPC32())
       Diags.Report(diag::err_drv_unsupported_opt_for_target)

clang/test/CodeGen/PowerPC/altivec.c

@@ -4,8 +4,8 @@
 // RUN: %clang_cc1 -target-feature +altivec -triple powerpc64le-unknown-unknown -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-LE
 // RUN: %clang_cc1 -target-feature +altivec -mabi=vec-extabi -target-cpu pwr8 -triple powerpc-unknown-aix -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-BE
 // RUN: %clang_cc1 -target-feature +altivec -mabi=vec-extabi -target-cpu pwr8 -triple powerpc64-unknown-aix -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-BE
-// RUN: %clang_cc1 -target-feature +altivec -mabi=vec-default -target-cpu pwr8 -triple powerpc-unknown-aix -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-BE
-// RUN: %clang_cc1 -target-feature +altivec -mabi=vec-default -target-cpu pwr8 -triple powerpc64-unknown-aix -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-BE
+// RUN: %clang_cc1 -target-feature +altivec -target-cpu pwr8 -triple powerpc-unknown-aix -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-BE
+// RUN: %clang_cc1 -target-feature +altivec -target-cpu pwr8 -triple powerpc64-unknown-aix -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-BE
 // RUN: %clang -S -emit-llvm -maltivec -mabi=vec-extabi -mcpu=pwr8 --target=powerpc-unknown-aix %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-BE
 // RUN: %clang -S -emit-llvm -maltivec -mabi=vec-extabi -mcpu=pwr8 --target=powerpc64-unknown-aix %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-BE
 // RUN: %clang -S -emit-llvm -maltivec -mabi=vec-default -mcpu=pwr8 --target=powerpc-unknown-aix -emit-llvm %s -o - | FileCheck %s --check-prefixes=CHECK,CHECK-BE

clang/test/Driver/aix-vec_extabi.c

@@ -13,4 +13,4 @@
 // EXTABI-SAME:  "-mabi=vec-extabi"
 
 // DFLTABI:      "-cc1"
-// DFLTABI-SAME: "-mabi=vec-default"
+// DFLTABI-NOT:  "-mabi=vec-extabi"