Passmanager: fix a problem with skipping the inliner pass

A pass is skipped if no other pass changed the function since the previous run of the same pass.
Don't do this is if a pass depends on the function bodies of called functions, e.g. the inliner.
Other passes might change the callees, e.g. function signature opts, which makes it worth to run the inliner
again, even if the function itself didn't change.

Author: eeckstein

include/swift/SILOptimizer/PassManager/PassManager.h

@@ -203,6 +203,8 @@ class SILPassManager {
   /// Set to true when a pass invalidates an analysis.
   bool CurrentPassHasInvalidated = false;
 
+  bool currentPassDependsOnCalleeBodies = false;
+
   /// True if we need to stop running passes and restart again on the
   /// same function.
   bool RestartPipeline = false;
@@ -337,6 +339,10 @@ class SILPassManager {
     CompletedPassesMap[F].reset();
   }
 
+  void setDependingOnCalleeBodies() {
+    currentPassDependsOnCalleeBodies = true;
+  }
+
   /// Reset the state of the pass manager and remove all transformation
   /// owned by the pass manager. Analysis passes will be kept.
   void resetAndRemoveTransformations();

lib/SILOptimizer/PassManager/PassManager.cpp

@@ -551,6 +551,7 @@ void SILPassManager::runPassOnFunction(unsigned TransIdx, SILFunction *F) {
   updateSILModuleStatsBeforeTransform(F->getModule(), SFT, *this, NumPassesRun);
 
   CurrentPassHasInvalidated = false;
+  currentPassDependsOnCalleeBodies = false;
   numSubpassesRun = 0;
 
   auto MatchFun = [&](const std::string &Str) -> bool {
@@ -652,7 +653,7 @@ void SILPassManager::runPassOnFunction(unsigned TransIdx, SILFunction *F) {
                                      duration.count());
 
   // Remember if this pass didn't change anything.
-  if (!CurrentPassHasInvalidated)
+  if (!CurrentPassHasInvalidated && !currentPassDependsOnCalleeBodies)
     completedPasses.set((size_t)SFT->getPassKind());
 
   if (getOptions().VerifyAll &&

lib/SILOptimizer/Transforms/PerformanceInliner.cpp

@@ -100,6 +100,7 @@ class SILPerformanceInliner {
   /// global_init attributes.
   InlineSelection WhatToInline;
 
+  SILPassManager *pm;
   DominanceAnalysis *DA;
   SILLoopAnalysis *LA;
   BasicCalleeAnalysis *BCA;
@@ -227,11 +228,12 @@ class SILPerformanceInliner {
 
 public:
   SILPerformanceInliner(StringRef PassName, SILOptFunctionBuilder &FuncBuilder,
-                        InlineSelection WhatToInline, DominanceAnalysis *DA,
+                        InlineSelection WhatToInline,
+                        SILPassManager *pm, DominanceAnalysis *DA,
                         SILLoopAnalysis *LA, BasicCalleeAnalysis *BCA,
                         OptimizationMode OptMode, OptRemark::Emitter &ORE)
       : PassName(PassName), FuncBuilder(FuncBuilder),
-        WhatToInline(WhatToInline), DA(DA), LA(LA), BCA(BCA), CBI(DA), ORE(ORE),
+        WhatToInline(WhatToInline), pm(pm), DA(DA), LA(LA), BCA(BCA), CBI(DA), ORE(ORE),
         OptMode(OptMode) {}
 
   bool inlineCallsIntoFunction(SILFunction *F);
@@ -934,6 +936,8 @@ void SILPerformanceInliner::collectAppliesToInline(
       if (!FullApplySite::isa(&*I))
         continue;
 
+      pm->setDependingOnCalleeBodies();
+
       FullApplySite AI = FullApplySite(&*I);
 
       auto *Callee = getEligibleFunction(AI, WhatToInline);
@@ -1155,8 +1159,8 @@ class SILPerformanceInlinerPass : public SILFunctionTransform {
 
     SILOptFunctionBuilder FuncBuilder(*this);
 
-    SILPerformanceInliner Inliner(getID(), FuncBuilder, WhatToInline, DA, LA,
-                                  BCA, OptMode, ORE);
+    SILPerformanceInliner Inliner(getID(), FuncBuilder, WhatToInline,
+                                  getPassManager(), DA, LA, BCA, OptMode, ORE);
 
     assert(getFunction()->isDefinition() &&
            "Expected only functions with bodies!");