[NFC] Used SILOption field for copy propagation.

Replaced the quad-state (of state which one was illegal) of two booleans
(EnableCopyPropagation and DisableCopyPropagation) with an enum.

Author: nate-chandler

include/swift/AST/SILOptions.h

@@ -44,6 +44,20 @@ enum class LexicalLifetimesOption : uint8_t {
   On,
 };
 
+enum class CopyPropagationOption : uint8_t {
+  // Do not add any copy propagation passes.
+  Off = 0,
+
+  // Only add the copy propagation passes requested by other flags, currently
+  // just -enable-ossa-modules.
+  RequestedPassesOnly,
+
+  // Add all relevant copy propagation passes.  If a setting, e.g.
+  // -enable-ossa-modules, requests to add copy propagation to the pipeline, do
+  // so.
+  On
+};
+
 class SILModule;
 
 class SILOptions {
@@ -64,15 +78,12 @@ class SILOptions {
   LexicalLifetimesOption LexicalLifetimes =
       LexicalLifetimesOption::DiagnosticMarkersOnly;
 
-  /// Force-run SIL copy propagation to shorten object lifetime in whatever
-  /// optimization pipeline is currently used.
-  /// When this is 'false' the pipeline has default behavior.
-  bool EnableCopyPropagation = false;
-
-  /// Disable SIL copy propagation to preserve object lifetime in whatever
+  /// Whether to run SIL copy propagation to shorten object lifetime in whatever
   /// optimization pipeline is currently used.
-  /// When this is 'false' the pipeline has default behavior.
-  bool DisableCopyPropagation = false;
+  ///
+  /// When this is 'RequestedPassesOnly' the pipeline has default behavior.
+  CopyPropagationOption CopyPropagation =
+      CopyPropagationOption::RequestedPassesOnly;
 
   /// Controls whether the SIL ARC optimizations are run.
   bool EnableARCOptimizations = true;

lib/Frontend/CompilerInvocation.cpp

@@ -1549,10 +1549,18 @@ static bool ParseSILArgs(SILOptions &Opts, ArgList &Args,
     Diags.diagnose(SourceLoc(), diag::error_invalid_arg_combination,
                    "enable-copy-propagation", "disable-copy-propagation");
     return true;
+  } else if (Args.hasArg(OPT_enable_copy_propagation) &&
+             !Args.hasArg(OPT_disable_copy_propagation)) {
+    Opts.CopyPropagation = CopyPropagationOption::On;
+  } else if (!Args.hasArg(OPT_enable_copy_propagation) &&
+             Args.hasArg(OPT_disable_copy_propagation)) {
+    Opts.CopyPropagation = CopyPropagationOption::Off;
+  } else /*if (!Args.hasArg(OPT_enable_copy_propagation) &&
+            !Args.hasArg(OPT_disable_copy_propagation))*/
+  {
+    Opts.CopyPropagation = CopyPropagationOption::RequestedPassesOnly;
   }
 
-  Opts.EnableCopyPropagation |= Args.hasArg(OPT_enable_copy_propagation);
-  Opts.DisableCopyPropagation |= Args.hasArg(OPT_disable_copy_propagation);
   Opts.EnableARCOptimizations &= !Args.hasArg(OPT_disable_arc_opts);
   Opts.EnableOSSAModules |= Args.hasArg(OPT_enable_ossa_modules);
   Opts.EnableOSSAOptimizations &= !Args.hasArg(OPT_disable_ossa_opts);

lib/SILOptimizer/PassManager/PassPipeline.cpp

@@ -190,10 +190,10 @@ static void addMandatoryDiagnosticOptPipeline(SILPassPipelinePlan &P) {
 
   // Only issue weak lifetime warnings for users who select object lifetime
   // optimization. The risk of spurious warnings outweighs the benefits.
-  if (P.getOptions().EnableCopyPropagation) {
+  if (P.getOptions().CopyPropagation == CopyPropagationOption::On) {
     P.addDiagnoseLifetimeIssues();
   }
-  
+
   P.addGlobalOpt();
   P.addPerformanceDiagnostics();
 
@@ -408,7 +408,7 @@ void addFunctionPasses(SILPassPipelinePlan &P,
   if (P.getOptions().EnableOSSAModules) {
     // We earlier eliminated ownership if we are not compiling the stdlib. Now
     // handle the stdlib functions, re-simplifying, eliminating ARC as we do.
-    if (!P.getOptions().DisableCopyPropagation) {
+    if (P.getOptions().CopyPropagation != CopyPropagationOption::Off) {
       P.addCopyPropagation();
     }
     P.addSemanticARCOpts();
@@ -432,7 +432,7 @@ void addFunctionPasses(SILPassPipelinePlan &P,
 
   // Clean up Semantic ARC before we perform additional post-inliner opts.
   if (P.getOptions().EnableOSSAModules) {
-    if (!P.getOptions().DisableCopyPropagation) {
+    if (P.getOptions().CopyPropagation != CopyPropagationOption::Off) {
       P.addCopyPropagation();
     }
     P.addSemanticARCOpts();
@@ -499,7 +499,7 @@ void addFunctionPasses(SILPassPipelinePlan &P,
 
   // Run a final round of ARC opts when ownership is enabled.
   if (P.getOptions().EnableOSSAModules) {
-    if (!P.getOptions().DisableCopyPropagation) {
+    if (P.getOptions().CopyPropagation != CopyPropagationOption::Off) {
       P.addCopyPropagation();
     }
     P.addSemanticARCOpts();
@@ -535,7 +535,7 @@ static void addPerfEarlyModulePassPipeline(SILPassPipelinePlan &P) {
   // Cleanup after SILGen: remove trivial copies to temporaries.
   P.addTempRValueOpt();
   // Cleanup after SILGen: remove unneeded borrows/copies.
-  if (P.getOptions().EnableCopyPropagation) {
+  if (P.getOptions().CopyPropagation == CopyPropagationOption::On) {
     P.addCopyPropagation();
   }
   P.addSemanticARCOpts();
@@ -853,7 +853,7 @@ SILPassPipelinePlan::getPerformancePassPipeline(const SILOptions &Options) {
   // Run one last copy propagation/semantic arc opts run before serialization/us
   // lowering ownership.
   if (P.getOptions().EnableOSSAModules) {
-    if (!P.getOptions().DisableCopyPropagation) {
+    if (P.getOptions().CopyPropagation != CopyPropagationOption::Off) {
       P.addCopyPropagation();
     }
     P.addSemanticARCOpts();
@@ -905,7 +905,7 @@ SILPassPipelinePlan::getOnonePassPipeline(const SILOptions &Options) {
   P.startPipeline("non-Diagnostic Enabling Mandatory Optimizations");
   P.addForEachLoopUnroll();
   P.addMandatoryCombine();
-  if (P.getOptions().EnableCopyPropagation) {
+  if (P.getOptions().CopyPropagation == CopyPropagationOption::On) {
     // MandatoryCopyPropagation should only be run at -Onone, not -O.
     P.addMandatoryCopyPropagation();
   }

lib/SILOptimizer/SILCombiner/SILCombine.cpp

@@ -537,9 +537,11 @@ class SILCombine : public SILFunctionTransform {
     auto *CHA = PM->getAnalysis<ClassHierarchyAnalysis>();
     auto *NLABA = PM->getAnalysis<NonLocalAccessBlockAnalysis>();
 
-    bool enableCopyPropagation = getOptions().EnableCopyPropagation;
+    bool enableCopyPropagation =
+        getOptions().CopyPropagation == CopyPropagationOption::On;
     if (getOptions().EnableOSSAModules) {
-      enableCopyPropagation = !getOptions().DisableCopyPropagation;
+      enableCopyPropagation =
+          getOptions().CopyPropagation != CopyPropagationOption::Off;
     }
 
     SILOptFunctionBuilder FuncBuilder(*this);

tools/sil-opt/SILOpt.cpp

@@ -529,11 +529,14 @@ int main(int argc, char **argv) {
     fprintf(stderr, "Error! Cannot specify both -enable-copy-propagation "
                     "and -disable-copy-propagation.");
     exit(-1);
+  } else if (EnableCopyPropagation && !DisableCopyPropagation) {
+    SILOpts.CopyPropagation = CopyPropagationOption::On;
+  } else if (!EnableCopyPropagation && DisableCopyPropagation) {
+    SILOpts.CopyPropagation = CopyPropagationOption::Off;
+  } else /*if (!EnableCopyPropagation && !DisableCopyPropagation)*/ {
+    SILOpts.CopyPropagation = CopyPropagationOption::RequestedPassesOnly;
   }
 
-  SILOpts.EnableCopyPropagation = EnableCopyPropagation;
-  SILOpts.DisableCopyPropagation = DisableCopyPropagation;
-
   if (EnableCopyPropagation)
     SILOpts.LexicalLifetimes = LexicalLifetimesOption::On;
   if (DisableCopyPropagation)