Rename disable-llvm-arc-opts => disable-swift-specific-llvm-optzns and make sure that we actually disable /all/ LLVM passes.

For instance, we were always running merge functions unconditionally if -O was
passed.

rdar://40097698

include/swift/AST/IRGenOptions.h

@@ -106,8 +106,8 @@ public:
   /// \brief Whether we should run LLVM optimizations after IRGen.
   unsigned DisableLLVMOptzns : 1;
 
-  /// \brief Whether we should run LLVM ARC optimizations after IRGen.
-  unsigned DisableLLVMARCOpts : 1;
+  /// Whether we should run swift specific LLVM optimizations after IRGen.
+  unsigned DisableSwiftSpecificLLVMOptzns : 1;
 
   /// \brief Whether we should run LLVM SLP vectorizer.
   unsigned DisableLLVMSLPVectorizer : 1;
@@ -182,7 +182,7 @@ public:
         Verify(true), OptMode(OptimizationMode::NotSet),
         Sanitizers(OptionSet<SanitizerKind>()),
         DebugInfoKind(IRGenDebugInfoKind::None), UseJIT(false),
-        DisableLLVMOptzns(false), DisableLLVMARCOpts(false),
+        DisableLLVMOptzns(false), DisableSwiftSpecificLLVMOptzns(false),
         DisableLLVMSLPVectorizer(false), DisableFPElim(true), Playground(false),
         EmitStackPromotionChecks(false), PrintInlineTree(false),
         EmbedMode(IRGenEmbedMode::None), HasValueNamesSetting(false),
@@ -197,7 +197,7 @@ public:
   unsigned getLLVMCodeGenOptionsHash() {
     unsigned Hash = (unsigned)OptMode;
     Hash = (Hash << 1) | DisableLLVMOptzns;
-    Hash = (Hash << 1) | DisableLLVMARCOpts;
+    Hash = (Hash << 1) | DisableSwiftSpecificLLVMOptzns;
     return Hash;
   }
 

include/swift/Option/FrontendOptions.td

@@ -217,8 +217,8 @@ def disable_llvm_optzns : Flag<["-"], "disable-llvm-optzns">,
 def disable_sil_perf_optzns : Flag<["-"], "disable-sil-perf-optzns">,
   HelpText<"Don't run SIL performance optimization passes">;
 
-def disable_llvm_arc_opts : Flag<["-"], "disable-llvm-arc-opts">,
-  HelpText<"Don't run LLVM ARC optimization passes.">;
+def disable_swift_specific_llvm_optzns : Flag<["-"], "disable-swift-specific-llvm-optzns">,
+  HelpText<"Don't run Swift specific LLVM optimization passes.">;
 
 def disable_llvm_slp_vectorizer : Flag<["-"], "disable-llvm-slp-vectorizer">,
   HelpText<"Don't run LLVM SLP vectorizer">;

lib/Frontend/CompilerInvocation.cpp

@@ -812,7 +812,8 @@ static bool ParseIRGenArgs(IRGenOptions &Opts, ArgList &Args,
   }
 
   Opts.DisableLLVMOptzns |= Args.hasArg(OPT_disable_llvm_optzns);
-  Opts.DisableLLVMARCOpts |= Args.hasArg(OPT_disable_llvm_arc_opts);
+  Opts.DisableSwiftSpecificLLVMOptzns |=
+      Args.hasArg(OPT_disable_swift_specific_llvm_optzns);
   Opts.DisableLLVMSLPVectorizer |= Args.hasArg(OPT_disable_llvm_slp_vectorizer);
   if (Args.hasArg(OPT_disable_llvm_verify))
     Opts.Verify = false;

lib/IRGen/GenHeap.cpp

@@ -1306,7 +1306,8 @@ llvm::Constant *IRGenModule::getFixLifetimeFn() {
 /// optimizer not to touch this value.
 void IRGenFunction::emitFixLifetime(llvm::Value *value) {
   // If we aren't running the LLVM ARC optimizer, we don't need to emit this.
-  if (!IGM.IRGen.Opts.shouldOptimize() || IGM.IRGen.Opts.DisableLLVMARCOpts)
+  if (!IGM.IRGen.Opts.shouldOptimize() ||
+      IGM.IRGen.Opts.DisableSwiftSpecificLLVMOptzns)
     return;
   if (doesNotRequireRefCounting(value)) return;
   emitUnaryRefCountCall(*this, IGM.getFixLifetimeFn(), value);

lib/IRGen/IRGen.cpp

@@ -176,9 +176,12 @@ void swift::performLLVMOptimizations(IRGenOptions &Opts, llvm::Module *Module,
         llvm::createAlwaysInlinerLegacyPass(/*insertlifetime*/false);
   }
 
+  bool RunSwiftSpecificLLVMOptzns =
+      !Opts.DisableSwiftSpecificLLVMOptzns && !Opts.DisableLLVMOptzns;
+
   // If the optimizer is enabled, we run the ARCOpt pass in the scalar optimizer
   // and the Contract pass as late as possible.
-  if (!Opts.DisableLLVMARCOpts && !Opts.DisableLLVMOptzns) {
+  if (RunSwiftSpecificLLVMOptzns) {
     PMBuilder.addExtension(PassManagerBuilder::EP_ScalarOptimizerLate,
                            addSwiftARCOptPass);
     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
@@ -208,9 +211,10 @@ void swift::performLLVMOptimizations(IRGenOptions &Opts, llvm::Module *Module,
                            addSanitizerCoveragePass);
   }
 
-  if (!Opts.DisableLLVMOptzns)
+  if (RunSwiftSpecificLLVMOptzns)
     addCoroutinePassesToExtensionPoints(PMBuilder);
 
+  if (RunSwiftSpecificLLVMOptzns)
     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
                            addSwiftMergeFunctionsPass);
 
@@ -224,7 +228,7 @@ void swift::performLLVMOptimizations(IRGenOptions &Opts, llvm::Module *Module,
 
   // The PMBuilder only knows about LLVM AA passes.  We should explicitly add
   // the swift AA pass after the other ones.
-  if (!Opts.DisableLLVMARCOpts && !Opts.DisableLLVMOptzns) {
+  if (RunSwiftSpecificLLVMOptzns) {
     FunctionPasses.add(createSwiftAAWrapperPass());
     FunctionPasses.add(createExternalAAWrapperPass([](Pass &P, Function &,
                                                       AAResults &AAR) {
@@ -253,7 +257,7 @@ void swift::performLLVMOptimizations(IRGenOptions &Opts, llvm::Module *Module,
 
   // The PMBuilder only knows about LLVM AA passes.  We should explicitly add
   // the swift AA pass after the other ones.
-  if (!Opts.DisableLLVMARCOpts && !Opts.DisableLLVMOptzns) {
+  if (RunSwiftSpecificLLVMOptzns) {
     ModulePasses.add(createSwiftAAWrapperPass());
     ModulePasses.add(createExternalAAWrapperPass([](Pass &P, Function &,
                                                     AAResults &AAR) {

utils/swift-autocomplete.bash

@@ -20,7 +20,7 @@ _swift_complete()
     # Don't know how to get the help for llvm options automatically.
     # So we use a grep'ed static list.
     COMPREPLY=( $(compgen -W "\
-      -disable-llvm-arc-opts \
+      -disable-swift-specific-llvm-optzns \
       -stack-promotion-limit \
       -view-cfg-max-columns \
       -view-cfg-long-line-behavior \