[clang] Support -Wa, options -mmsa and -mno-msa (#99615)

Co-authored-by: Fangrui Song <[email protected]>

Author: yingopq

clang/include/clang/Basic/CodeGenOptions.def

@@ -176,6 +176,7 @@ CODEGENOPT(MergeAllConstants , 1, 1) ///< Merge identical constants.
 CODEGENOPT(MergeFunctions    , 1, 0) ///< Set when -fmerge-functions is enabled.
 CODEGENOPT(NoCommon          , 1, 0) ///< Set when -fno-common or C++ is enabled.
 CODEGENOPT(NoExecStack       , 1, 0) ///< Set when -Wa,--noexecstack is enabled.
+CODEGENOPT(MipsMsa           , 1, 0) ///< Set when -Wa,-mmsa is enabled.
 CODEGENOPT(FatalWarnings     , 1, 0) ///< Set when -Wa,--fatal-warnings is
                                      ///< enabled.
 CODEGENOPT(NoWarn            , 1, 0) ///< Set when -Wa,--no-warn is enabled.

clang/include/clang/Driver/Options.td

@@ -5383,7 +5383,9 @@ def mmadd4 : Flag<["-"], "mmadd4">, Group<m_mips_Features_Group>,
 def mno_madd4 : Flag<["-"], "mno-madd4">, Group<m_mips_Features_Group>,
   HelpText<"Disable the generation of 4-operand madd.s, madd.d and related instructions.">;
 def mmsa : Flag<["-"], "mmsa">, Group<m_mips_Features_Group>,
-  HelpText<"Enable MSA ASE (MIPS only)">;
+  Visibility<[ClangOption, CC1Option, CC1AsOption]>,
+  HelpText<"Enable MSA ASE (MIPS only)">,
+  MarshallingInfoFlag<CodeGenOpts<"MipsMsa">>;
 def mno_msa : Flag<["-"], "mno-msa">, Group<m_mips_Features_Group>,
   HelpText<"Disable MSA ASE (MIPS only)">;
 def mmt : Flag<["-"], "mmt">, Group<m_mips_Features_Group>,

clang/lib/Driver/ToolChains/Clang.cpp

@@ -2556,6 +2556,7 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
   bool Crel = false, ExperimentalCrel = false;
   bool UseRelaxRelocations = C.getDefaultToolChain().useRelaxRelocations();
   bool UseNoExecStack = false;
+  bool Msa = false;
   const char *MipsTargetFeature = nullptr;
   StringRef ImplicitIt;
   for (const Arg *A :
@@ -2665,7 +2666,14 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
           CmdArgs.push_back("-soft-float");
           continue;
         }
-
+        if (Value == "-mmsa") {
+          Msa = true;
+          continue;
+        }
+        if (Value == "-mno-msa") {
+          Msa = false;
+          continue;
+        }
         MipsTargetFeature = llvm::StringSwitch<const char *>(Value)
                                 .Case("-mips1", "+mips1")
                                 .Case("-mips2", "+mips2")
@@ -2685,6 +2693,7 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
                                 .Default(nullptr);
         if (MipsTargetFeature)
           continue;
+        break;
       }
 
       if (Value == "-force_cpusubtype_ALL") {
@@ -2777,6 +2786,8 @@ static void CollectArgsForIntegratedAssembler(Compilation &C,
           << "-Wa,--crel" << D.getTargetTriple();
     }
   }
+  if (Msa)
+    CmdArgs.push_back("-mmsa");
   if (!UseRelaxRelocations)
     CmdArgs.push_back("-mrelax-relocations=no");
   if (UseNoExecStack)

clang/test/Driver/mips-msa.c

@@ -0,0 +1,12 @@
+// RUN: %clang -### -c --target=mips64el-unknown-linux-gnuabi64 \
+// RUN:   -Wa,-mmsa %s -Werror 2>&1 | FileCheck %s --check-prefix=CHECK-MMSA
+// CHECK-MMSA: "-cc1" {{.*}}"-mmsa"
+
+// RUN: %clang -### -c --target=mips64el-unknown-linux-gnuabi64 \
+// RUN:   -Wa,-mmsa,-mno-msa %s -Werror 2>&1 | FileCheck %s --check-prefix=CHECK-NOMMSA
+// CHECK-NOMMSA:     "-cc1"
+// CHECK-NOMMSA-NOT: "-mssa"
+
+// RUN: not %clang -### -c --target=x86_64 -Wa,-mmsa -Wa,-mno-msa %s 2>&1 | FileCheck %s --check-prefix=ERR
+// ERR: error: unsupported argument '-mmsa' to option '-Wa,'
+// ERR: error: unsupported argument '-mno-msa' to option '-Wa,'