Re-add #30710

Reverts the reversion in #34188.

Bisection points to #34188 as the cause of a crasher that looks to be the
result of a miscompile. Adding this back resolves the crasher.

Details of the crash:
The `DiscontiguousSliceSlicing` test in
validation-test/StdlibUnittest/RangeSet.swift crashes in the `every()`
function on line 15. When the contents of this function are replaced with a
functional equivalent that uses different syntax, the crash resolves.

include/swift/SILOptimizer/Analysis/FunctionOrder.h

@@ -31,7 +31,6 @@ class BottomUpFunctionOrder {
   typedef TinyPtrVector<SILFunction *> SCC;
 
 private:
-  SILModule &M;
   llvm::SmallVector<SCC, 32> TheSCCs;
   llvm::SmallVector<SILFunction *, 32> TheFunctions;
 
@@ -44,24 +43,33 @@ class BottomUpFunctionOrder {
   llvm::SmallSetVector<SILFunction *, 4> DFSStack;
 
 public:
-  BottomUpFunctionOrder(SILModule &M, BasicCalleeAnalysis *BCA)
-      : M(M), BCA(BCA), NextDFSNum(0) {}
+  // SWIFT_ENABLE_TENSORFLOW
+  BottomUpFunctionOrder(BasicCalleeAnalysis *BCA)
+      : BCA(BCA), NextDFSNum(0) {}
+
+  /// DFS on 'F' to compute bottom up order
+  void computeBottomUpOrder(SILFunction *F) {
+     DFS(F);
+  }
+
+  /// DFS on all functions in the module to compute bottom up order
+  void computeBottomUpOrder(SILModule *M) {
+    for (auto &F : *M)
+      DFS(&F);
+  }
+  // SWIFT_ENABLE_TENSORFLOW END
 
   /// Get the SCCs in bottom-up order.
   ArrayRef<SCC> getSCCs() {
-    if (!TheSCCs.empty())
-      return TheSCCs;
-
-    FindSCCs(M);
     return TheSCCs;
   }
 
-  /// Get a flattened view of all functions in all the SCCs in
-  /// bottom-up order
-  ArrayRef<SILFunction *> getFunctions() {
+  // SWIFT_ENABLE_TENSORFLOW
+  /// Get a flattened view of all functions in all the SCCs in bottom-up order
+  ArrayRef<SILFunction *> getBottomUpOrder() {
+  // SWIFT_ENABLE_TENSORFLOW END
     if (!TheFunctions.empty())
       return TheFunctions;
-
     for (auto SCC : getSCCs())
       for (auto *F : SCC)
         TheFunctions.push_back(F);
@@ -71,7 +79,6 @@ class BottomUpFunctionOrder {
 
 private:
   void DFS(SILFunction *F);
-  void FindSCCs(SILModule &M);
 };
 
 } // end namespace swift

lib/SILOptimizer/Analysis/FunctionOrder.cpp

@@ -73,8 +73,3 @@ void BottomUpFunctionOrder::DFS(SILFunction *Start) {
     TheSCCs.push_back(CurrentSCC);
   }
 }
-
-void BottomUpFunctionOrder::FindSCCs(SILModule &M) {
-  for (auto &F : M)
-    DFS(&F);
-}

lib/SILOptimizer/PassManager/PassManager.cpp

@@ -533,8 +533,11 @@ runFunctionPasses(unsigned FromTransIdx, unsigned ToTransIdx) {
     return;
 
   BasicCalleeAnalysis *BCA = getAnalysis<BasicCalleeAnalysis>();
-  BottomUpFunctionOrder BottomUpOrder(*Mod, BCA);
-  auto BottomUpFunctions = BottomUpOrder.getFunctions();
+  // SWIFT_ENABLE_TENSORFLOW
+  BottomUpFunctionOrder BottomUpOrder(BCA);
+  BottomUpOrder.computeBottomUpOrder(Mod);
+  auto BottomUpFunctions = BottomUpOrder.getBottomUpOrder();
+  // SWIFT_ENABLE_TENSORFLOW END
 
   assert(FunctionWorklist.empty() && "Expected empty function worklist!");
 
@@ -587,6 +590,49 @@ runFunctionPasses(unsigned FromTransIdx, unsigned ToTransIdx) {
       ++Entry.PipelineIdx;
     }
     clearRestartPipeline();
+
+    // SWIFT_ENABLE_TENSORFLOW
+    if (TailIdx == (FunctionWorklist.size() - 1))  {
+      // No new functions to process
+      continue;
+    }
+
+    // Compute the bottom up order of the new functions and the callees in it
+    BottomUpFunctionOrder SubBottomUpOrder(BCA);
+    // Initialize BottomUpFunctionOrder with new functions
+    for (auto It = FunctionWorklist.begin() + TailIdx + 1;
+         It != FunctionWorklist.end(); It++) {
+      SubBottomUpOrder.computeBottomUpOrder(It->F);
+    }
+    auto NewFunctionsBottomUp = SubBottomUpOrder.getBottomUpOrder();
+    SmallPtrSet<SILFunction *, 8> NewBottomUpSet(NewFunctionsBottomUp.begin(),
+                                                 NewFunctionsBottomUp.end());
+
+    // Remove all the functions in the new bottom up order from FunctionWorklist
+    llvm::DenseMap<SILFunction *, WorklistEntry> FunctionsToReorder;
+    auto RemoveFn = [&FunctionsToReorder,
+                     &NewBottomUpSet](WorklistEntry Entry) {
+      if (NewBottomUpSet.find(Entry.F) == NewBottomUpSet.end()) {
+        return false;
+      }
+      FunctionsToReorder.insert(std::make_pair(Entry.F, Entry));
+      return true;
+    };
+    std::remove_if(FunctionWorklist.begin(), FunctionWorklist.end(), RemoveFn);
+    FunctionWorklist.erase((FunctionWorklist.begin() + FunctionWorklist.size() -
+                            FunctionsToReorder.size()),
+                           FunctionWorklist.end());
+
+    // Add back the functions in the new bottom up order to the FunctionWorklist
+    for (auto it = NewFunctionsBottomUp.rbegin();
+         it != NewFunctionsBottomUp.rend(); it++) {
+      auto Entry = FunctionsToReorder.find(*it);
+      if (Entry == FunctionsToReorder.end()) {
+        continue;
+      }
+      FunctionWorklist.push_back((*Entry).second);
+    }
+    // SWIFT_ENABLE_TENSORFLOW END
   }
 }
 

lib/SILOptimizer/UtilityPasses/FunctionOrderPrinter.cpp

@@ -35,8 +35,10 @@ class FunctionOrderPrinterPass : public SILModuleTransform {
   /// The entry point to the transformation.
   void run() override {
     BCA = getAnalysis<BasicCalleeAnalysis>();
-    auto &M = *getModule();
-    BottomUpFunctionOrder Orderer(M, BCA);
+    // SWIFT_ENABLE_TENSORFLOW
+    BottomUpFunctionOrder Orderer(BCA);
+    Orderer.computeBottomUpOrder(getModule());
+    // SWIFT_ENABLE_TENSORFLOW END
 
     llvm::outs() << "Bottom up function order:\n";
     auto SCCs = Orderer.getSCCs();

test/DebugInfo/inlined-generics-basic.swift

@@ -91,9 +91,11 @@ public class C<R> {
 // IR-LABEL: ret void
 
 // IR: ![[BOOL:[0-9]+]] = !DICompositeType({{.*}}name: "Bool"
-// IR: ![[LET_BOOL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_const_type, baseType: ![[BOOL]])
 // IR: ![[INT:[0-9]+]] = !DICompositeType({{.*}}name: "Int"
 // IR: ![[LET_INT:[0-9]+]] = !DIDerivedType(tag: DW_TAG_const_type, baseType: ![[INT]])
+// SWIFT_ENABLE_TENSORFLOW
+// IR: ![[LET_BOOL:[0-9]+]] = !DIDerivedType(tag: DW_TAG_const_type, baseType: ![[BOOL]])
+// SWIFT_ENABLE_TENSORFLOW END
 // IR: ![[TAU_0_0:[0-9]+]] = {{.*}}DW_TAG_structure_type, name: "$sxD",
 // IR: ![[LET_TAU_0_0:[0-9]+]] = !DIDerivedType(tag: DW_TAG_const_type, baseType: ![[TAU_0_0]])
 // IR: ![[TAU_1_0:[0-9]+]] = {{.*}}DW_TAG_structure_type, name: "$sqd__D",