Add the frontend option -disable-sil-perf-optzns.

Swift SVN r20604

include/swift/AST/SILOptions.h

@@ -50,6 +50,11 @@ public:
   /// Controls whether the SIL ARC optimizations are run.
   bool EnableARCOptimizations = true;
 
+  /// Should we run any SIL performance optimizations
+  ///
+  /// Useful when you want to enable -O LLVM opts but not -O SIL opts.
+  bool DisableSILPerfOptimizations = false;
+
   /// Controls whether or not paranoid verification checks are run.
   bool VerifyAll = false;
 

include/swift/Option/FrontendOptions.td

@@ -109,6 +109,9 @@ def disable_diagnostic_passes : Flag<["-"], "disable-diagnostic-passes">,
 def disable_llvm_optzns : Flag<["-"], "disable-llvm-optzns">,
   HelpText<"Don't run LLVM optimization passes">;
 
+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.">;
 

lib/Frontend/CompilerInvocation.cpp

@@ -766,6 +766,7 @@ static bool ParseSILArgs(SILOptions &Opts, ArgList &Args,
   Opts.RemoveRuntimeAsserts |= Args.hasArg(OPT_remove_runtime_asserts);
 
   Opts.EnableARCOptimizations |= !Args.hasArg(OPT_disable_arc_opts);
+  Opts.DisableSILPerfOptimizations |= Args.hasArg(OPT_disable_sil_perf_optzns);
   Opts.VerifyAll |= Args.hasArg(OPT_sil_verify_all);
   Opts.PrintAll |= Args.hasArg(OPT_sil_print_all);
   Opts.TimeTransforms |= Args.hasArg(OPT_sil_time_transforms);

lib/SILPasses/Passes.cpp

@@ -148,9 +148,11 @@ void AddSSAPasses(SILPassManager &PM, SILModule &Module,
   PM.add(createGlobalARCOpts());
 }
 
-
 void swift::runSILOptimizationPasses(SILModule &Module,
                                      const SILOptions &Options) {
+  if (Options.DisableSILPerfOptimizations)
+    return;
+
   if (Options.DebugSerialization) {
     SILPassManager PM(&Module, Options);
     registerAnalysisPasses(PM, &Module);