3 files changed, 9 insertions, 35 deletions

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index c39c1c7e3cf..6aff423bd18 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4678,11 +4678,15 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
   if (TC.SupportsProfiling())
     Args.AddLastArg(CmdArgs, options::OPT_mfentry);
 
+  // -flax-vector-conversions is default.
+  if (!Args.hasFlag(options::OPT_flax_vector_conversions,
+                    options::OPT_fno_lax_vector_conversions))
+    CmdArgs.push_back("-fno-lax-vector-conversions");
+
   if (Args.getLastArg(options::OPT_fapple_kext) ||
       (Args.hasArg(options::OPT_mkernel) && types::isCXX(InputType)))
     CmdArgs.push_back("-fapple-kext");
 
-  Args.AddLastArg(CmdArgs, options::OPT_flax_vector_conversions_EQ);
   Args.AddLastArg(CmdArgs, options::OPT_fobjc_sender_dependent_dispatch);
   Args.AddLastArg(CmdArgs, options::OPT_fdiagnostics_print_source_range_info);
   Args.AddLastArg(CmdArgs, options::OPT_fdiagnostics_parseable_fixits);
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 0e29e6d9d4d..3db0b8827ad 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2265,7 +2265,7 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
   if (Opts.OpenCL) {
     Opts.AltiVec = 0;
     Opts.ZVector = 0;
-    Opts.setLaxVectorConversions(LangOptions::LaxVectorConversionKind::None);
+    Opts.LaxVectorConversions = 0;
     Opts.setDefaultFPContractMode(LangOptions::FPC_On);
     Opts.NativeHalfType = 1;
     Opts.NativeHalfArgsAndReturns = 1;
@@ -2667,18 +2667,8 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   Opts.WritableStrings = Args.hasArg(OPT_fwritable_strings);
   Opts.ConstStrings = Args.hasFlag(OPT_fconst_strings, OPT_fno_const_strings,
                                    Opts.ConstStrings);
-  if (Arg *A = Args.getLastArg(OPT_flax_vector_conversions_EQ)) {
-    using LaxKind = LangOptions::LaxVectorConversionKind;
-    if (auto Kind = llvm::StringSwitch<Optional<LaxKind>>(A->getValue())
-                        .Case("none", LaxKind::None)
-                        .Case("integer", LaxKind::Integer)
-                        .Case("all", LaxKind::All)
-                        .Default(llvm::None))
-      Opts.setLaxVectorConversions(*Kind);
-    else
-      Diags.Report(diag::err_drv_invalid_value)
-          << A->getAsString(Args) << A->getValue();
-  }
+  if (Args.hasArg(OPT_fno_lax_vector_conversions))
+    Opts.LaxVectorConversions = 0;
   if (Args.hasArg(OPT_fno_threadsafe_statics))
     Opts.ThreadsafeStatics = 0;
   Opts.Exceptions = Args.hasArg(OPT_fexceptions);
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index 84520052c61..849298433ac 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/clang/lib/Sema/SemaExpr.cpp
@@ -6498,28 +6498,8 @@ bool Sema::areLaxCompatibleVectorTypes(QualType srcTy, QualType destTy) {
 bool Sema::isLaxVectorConversion(QualType srcTy, QualType destTy) {
   assert(destTy->isVectorType() || srcTy->isVectorType());
 
-  switch (Context.getLangOpts().getLaxVectorConversions()) {
-  case LangOptions::LaxVectorConversionKind::None:
+  if (!Context.getLangOpts().LaxVectorConversions)
     return false;
-
-  case LangOptions::LaxVectorConversionKind::Integer:
-    if (!srcTy->isIntegralOrEnumerationType()) {
-      auto *Vec = srcTy->getAs<VectorType>();
-      if (!Vec || !Vec->getElementType()->isIntegralOrEnumerationType())
-        return false;
-    }
-    if (!destTy->isIntegralOrEnumerationType()) {
-      auto *Vec = destTy->getAs<VectorType>();
-      if (!Vec || !Vec->getElementType()->isIntegralOrEnumerationType())
-        return false;
-    }
-    // OK, integer (vector) -> integer (vector) bitcast.
-    break;
-
-    case LangOptions::LaxVectorConversionKind::All:
-    break;
-  }
-
   return areLaxCompatibleVectorTypes(srcTy, destTy);
 }