NFC: Move NumThreads from SILOptions to IRGenOptions

The option is only needed for IRGen.

Author: hamishknight

include/swift/AST/IRGenOptions.h

@@ -284,6 +284,9 @@ class IRGenOptions {
   /// Whether to disable using mangled names for accessing concrete type metadata.
   unsigned DisableConcreteTypeMetadataMangledNameAccessors : 1;
 
+  /// The number of threads for multi-threaded code generation.
+  unsigned NumThreads = 0;
+
   /// Path to the profdata file to be used for PGO, or the empty string.
   std::string UseProfile = "";
 
@@ -383,6 +386,10 @@ class IRGenOptions {
   llvm::hash_code getPCHHashComponents() const {
     return llvm::hash_value(0);
   }
+
+  bool hasMultipleIRGenThreads() const { return NumThreads > 1; }
+  bool shouldPerformIRGenerationInParallel() const { return NumThreads != 0; }
+  bool hasMultipleIGMs() const { return hasMultipleIRGenThreads(); }
 };
 
 } // end namespace swift

include/swift/AST/SILOptions.h

@@ -40,9 +40,6 @@ class SILOptions {
   /// Controls the aggressiveness of the loop unroller.
   int UnrollThreshold = 250;
 
-  /// The number of threads for multi-threaded code generation.
-  unsigned NumThreads = 0;
-  
   /// Controls whether to pull in SIL from partial modules during the
   /// merge modules step. Could perhaps be merged with the link mode
   /// above but the interactions between all the flags are tricky.
@@ -183,10 +180,6 @@ class SILOptions {
   bool shouldOptimize() const {
     return OptMode > OptimizationMode::NoOptimization;
   }
-
-  bool hasMultipleIRGenThreads() const { return NumThreads > 1; }
-  bool shouldPerformIRGenerationInParallel() const { return NumThreads != 0; }
-  bool hasMultipleIGMs() const { return hasMultipleIRGenThreads(); }
 };
 
 } // end namespace swift

lib/Frontend/CompilerInvocation.cpp

@@ -993,18 +993,6 @@ static bool ParseSILArgs(SILOptions &Opts, ArgList &Args,
       return true;
     }
   }
-  if (const Arg *A = Args.getLastArg(OPT_num_threads)) {
-    if (StringRef(A->getValue()).getAsInteger(10, Opts.NumThreads)) {
-      Diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
-                     A->getAsString(Args), A->getValue());
-      return true;
-    }
-    if (environmentVariableRequestedMaximumDeterminism()) {
-      Opts.NumThreads = 1;
-      Diags.diagnose(SourceLoc(), diag::remark_max_determinism_overriding,
-                     "-num-threads");
-    }
-  }
 
   // If we're only emitting a module, stop optimizations once we've serialized
   // the SIL for the module.
@@ -1209,7 +1197,7 @@ static bool ParseTBDGenArgs(TBDGenOptions &Opts, ArgList &Args,
                             CompilerInvocation &Invocation) {
   using namespace options;
 
-  Opts.HasMultipleIGMs = Invocation.getSILOptions().hasMultipleIGMs();
+  Opts.HasMultipleIGMs = Invocation.getIRGenOptions().hasMultipleIGMs();
 
   if (const Arg *A = Args.getLastArg(OPT_module_link_name)) {
     Opts.ModuleLinkName = A->getValue();
@@ -1543,6 +1531,19 @@ static bool ParseIRGenArgs(IRGenOptions &Opts, ArgList &Args,
         getRuntimeCompatVersion();
   }
 
+  if (const Arg *A = Args.getLastArg(OPT_num_threads)) {
+    if (StringRef(A->getValue()).getAsInteger(10, Opts.NumThreads)) {
+      Diags.diagnose(SourceLoc(), diag::error_invalid_arg_value,
+                     A->getAsString(Args), A->getValue());
+      return true;
+    }
+    if (environmentVariableRequestedMaximumDeterminism()) {
+      Opts.NumThreads = 1;
+      Diags.diagnose(SourceLoc(), diag::remark_max_determinism_overriding,
+                     "-num-threads");
+    }
+  }
+
   return false;
 }
 

lib/IRGen/IRGen.cpp

@@ -1280,7 +1280,7 @@ static void performParallelIRGeneration(
 
   // Start all the threads and do the LLVM compilation.
 
-  LLVMCodeGenThreads codeGenThreads(&irgen, &DiagMutex, SILMod->getOptions().NumThreads - 1);
+  LLVMCodeGenThreads codeGenThreads(&irgen, &DiagMutex, Opts.NumThreads - 1);
   codeGenThreads.startThreads();
 
   // Free the memory occupied by the SILModule.
@@ -1301,7 +1301,7 @@ GeneratedModule swift::performIRGeneration(
     const PrimarySpecificPaths &PSPs,
     ArrayRef<std::string> parallelOutputFilenames,
     llvm::GlobalVariable **outModuleHash, llvm::StringSet<> *LinkerDirectives) {
-  if (SILMod->getOptions().shouldPerformIRGenerationInParallel() &&
+  if (Opts.shouldPerformIRGenerationInParallel() &&
       !parallelOutputFilenames.empty()) {
     ::performParallelIRGeneration(Opts, M, std::move(SILMod), ModuleName,
                                   parallelOutputFilenames, LinkerDirectives);