Merge pull request #60959 from gottesmm/pr-3faa3ea6134632ab1926bb5fcf0957025481cc8d

[move-only] Move the various passes closer to their final positions.

Author: gottesmm

lib/SIL/Verifier/SILVerifier.cpp

@@ -4744,8 +4744,18 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
         if (F.getModule().getStage() != SILStage::Lowered) {
           // During the lowered stage, a function type might have different
           // signature
-          require(eltArgTy == bbArgTy,
-                  "switch_enum destination bbarg must match case arg type");
+          //
+          // We allow for move only wrapped enums to have trivial payloads that
+          // are not move only wrapped. This occurs since we want to lower
+          // trivial move only wrapped types earlier in the pipeline than
+          // non-trivial types.
+          if (bbArgTy.isTrivial(F)) {
+            require(eltArgTy == bbArgTy.copyingMoveOnlyWrapper(eltArgTy),
+                    "switch_enum destination bbarg must match case arg type");
+          } else {
+            require(eltArgTy == bbArgTy,
+                    "switch_enum destination bbarg must match case arg type");
+          }
         }
         require(!dest->getArguments()[0]->getType().isAddress(),
                 "switch_enum destination bbarg type must not be an address");

lib/SILOptimizer/Mandatory/MoveOnlyWrappedTypeEliminator.cpp

@@ -93,7 +93,7 @@ struct SILMoveOnlyWrappedTypeEliminatorVisitor
       endBorrows.push_back(ebi);
     }
     for (auto *ebi : endBorrows) {
-      ebi->eraseFromParent();
+      eraseFromParent(ebi);
     }
     si->replaceAllUsesWith(si->getDest());
     return eraseFromParent(si);
@@ -183,19 +183,32 @@ struct SILMoveOnlyWrappedTypeEliminatorVisitor
   NO_UPDATE_NEEDED(DestroyAddr)
   NO_UPDATE_NEEDED(DeallocStack)
   NO_UPDATE_NEEDED(Branch)
-  NO_UPDATE_NEEDED(UncheckedAddrCast)
   NO_UPDATE_NEEDED(RefElementAddr)
-  NO_UPDATE_NEEDED(Upcast)
   NO_UPDATE_NEEDED(CheckedCastBranch)
   NO_UPDATE_NEEDED(Object)
   NO_UPDATE_NEEDED(OpenExistentialRef)
   NO_UPDATE_NEEDED(ConvertFunction)
   NO_UPDATE_NEEDED(RefToBridgeObject)
   NO_UPDATE_NEEDED(BridgeObjectToRef)
-  NO_UPDATE_NEEDED(UnconditionalCheckedCast)
   NO_UPDATE_NEEDED(ClassMethod)
 #undef NO_UPDATE_NEEDED
 
+  bool eliminateIdentityCast(SingleValueInstruction *svi) {
+    if (svi->getOperand(0)->getType() != svi->getType())
+      return false;
+    svi->replaceAllUsesWith(svi->getOperand(0));
+    eraseFromParent(svi);
+    return true;
+  }
+
+#define ELIMINATE_POTENTIAL_IDENTITY_CAST(NAME) \
+  bool visit##NAME##Inst(NAME##Inst *cast) { \
+    return eliminateIdentityCast(cast); \
+  }
+  ELIMINATE_POTENTIAL_IDENTITY_CAST(Upcast)
+  ELIMINATE_POTENTIAL_IDENTITY_CAST(UncheckedAddrCast)
+  ELIMINATE_POTENTIAL_IDENTITY_CAST(UnconditionalCheckedCast)
+#undef ELIMINATE_POTENTIAL_IDENTITY_CAST
   // We handle apply sites by just inserting a convert_function that converts
   // the original function type into a function type without move only. This is
   // safe since adding/removing moveonlywrapped types is ABI neutral.

lib/SILOptimizer/PassManager/PassPipeline.cpp

@@ -128,6 +128,19 @@ static void addMandatoryDiagnosticOptPipeline(SILPassPipelinePlan &P) {
   P.addAllocBoxToStack();
   P.addNoReturnFolding();
   addDefiniteInitialization(P);
+
+
+  //===---
+  // Ownership Optimizations
+  //
+
+  P.addMoveKillsCopyableAddressesChecker();
+  P.addMoveOnlyObjectChecker(); // Check noImplicitCopy and move only
+                                // types.
+  P.addMoveKillsCopyableValuesChecker(); // No uses after _move of copyable
+                                         //   value.
+  P.addTrivialMoveOnlyTypeEliminator();
+
   P.addAddressLowering();
 
   P.addFlowIsolation();
@@ -159,34 +172,10 @@ static void addMandatoryDiagnosticOptPipeline(SILPassPipelinePlan &P) {
   P.addMandatoryInlining();
   P.addMandatorySILLinker();
 
-  // Before we promote any loads, perform _move checking for addresses.
-  P.addMoveKillsCopyableAddressesChecker();
-
-  // Now perform move object checking. We again do this before predictable
-  // memory access opts to ensure that we do not get any non-source related
-  // diagnostics due to value promotion.
-  P.addMoveOnlyObjectChecker(); // Check noImplicitCopy and move only
-                                // types.
-
   // Promote loads as necessary to ensure we have enough SSA formation to emit
   // SSA based diagnostics.
   P.addPredictableMemoryAccessOptimizations();
 
-  // Now that we have promoted simple loads for SSA based diagnostics, perform
-  // SSA based move function checking and no implicit copy checking.
-  P.addMoveKillsCopyableValuesChecker(); // No uses after _move of copyable
-                                         //   value.
-
-  // Now that we have run move only checking, eliminate SILMoveOnly wrapped
-  // trivial types from the IR. We cannot introduce extra "copies" of trivial
-  // things so we can simplify our implementation by eliminating them here.
-  P.addTrivialMoveOnlyTypeEliminator();
-
-  // As a temporary measure, we also eliminate move only for non-trivial types
-  // until we can audit the later part of the pipeline. Eventually, this should
-  // occur before IRGen.
-  P.addMoveOnlyTypeEliminator();
-
   // This phase performs optimizations necessary for correct interoperation of
   // Swift os log APIs with C os_log ABIs.
   // Pass dependencies: this pass depends on MandatoryInlining and Mandatory
@@ -228,6 +217,11 @@ static void addMandatoryDiagnosticOptPipeline(SILPassPipelinePlan &P) {
 
   // Canonical swift requires all non cond_br critical edges to be split.
   P.addSplitNonCondBrCriticalEdges();
+
+  // As a temporary measure, we also eliminate move only for non-trivial types
+  // until we can audit the later part of the pipeline. Eventually, this should
+  // occur before IRGen.
+  P.addMoveOnlyTypeEliminator();
 }
 
 SILPassPipelinePlan