[eager-specializer] Fix for ownership and add a bunch of missing code coverage for ossa.

Specifically, we were missing a bunch of coverage around specializing guaranteed
parameters and non-trivial values in general.

Author: gottesmm

include/swift/SIL/SILBuilder.h

@@ -1853,7 +1853,18 @@ class SILBuilder {
   // Unchecked cast helpers
   //===--------------------------------------------------------------------===//
 
-  // Create the appropriate cast instruction based on result type.
+  /// Create the appropriate cast instruction based on result type.
+  ///
+  /// NOTE: We allow for non-layout compatible casts that shrink the underlying
+  /// type we are bit casting!
+  SingleValueInstruction *
+  createUncheckedReinterpretCast(SILLocation Loc, SILValue Op, SILType Ty);
+
+  /// Create an appropriate cast instruction based on result type.
+  ///
+  /// NOTE: This assumes that the input and the result cast are layout
+  /// compatible. Reduces to createUncheckedReinterpretCast when ownership is
+  /// disabled.
   SingleValueInstruction *createUncheckedBitCast(SILLocation Loc, SILValue Op,
                                                  SILType Ty);
 

include/swift/SILOptimizer/Utils/CFGOptUtils.h

@@ -107,6 +107,10 @@ bool splitCriticalEdgesFrom(SILBasicBlock *fromBB,
                             DominanceInfo *domInfo = nullptr,
                             SILLoopInfo *loopInfo = nullptr);
 
+/// Splits all critical edges that have `toBB` as a destination.
+bool splitCriticalEdgesTo(SILBasicBlock *toBB, DominanceInfo *domInfo = nullptr,
+                          SILLoopInfo *loopInfo = nullptr);
+
 /// Splits the edges between two basic blocks.
 ///
 /// Updates dominance information and loop information if not null.

lib/IRGen/LoadableByAddress.cpp

@@ -1544,7 +1544,7 @@ void LoadableStorageAllocation::
                                             storageType);
     if (pass.containsDifferentFunctionSignature(pass.F->getLoweredFunctionType(),
                                                 storageType)) {
-      auto *castInstr = argBuilder.createUncheckedBitCast(
+      auto *castInstr = argBuilder.createUncheckedReinterpretCast(
           RegularLocation(const_cast<ValueDecl *>(arg->getDecl())), arg,
           newSILType);
       arg->replaceAllUsesWith(castInstr);
@@ -1912,8 +1912,8 @@ static void castTupleInstr(SingleValueInstruction *instr, IRGenModule &Mod,
   switch (instr->getKind()) {
   // Add cast to the new sil function type:
   case SILInstructionKind::TupleExtractInst: {
-    castInstr = castBuilder.createUncheckedBitCast(instr->getLoc(), instr,
-                                                   newSILType.getObjectType());
+    castInstr = castBuilder.createUncheckedReinterpretCast(
+        instr->getLoc(), instr, newSILType.getObjectType());
     break;
   }
   case SILInstructionKind::TupleElementAddrInst: {
@@ -2471,8 +2471,8 @@ getOperandTypeWithCastIfNecessary(SILInstruction *containingInstr, SILValue op,
     }
     assert(currSILType.isObject() && "Expected an object type");
     if (newSILType != currSILType) {
-      auto castInstr = builder.createUncheckedBitCast(containingInstr->getLoc(),
-                                                      op, newSILType);
+      auto castInstr = builder.createUncheckedReinterpretCast(
+          containingInstr->getLoc(), op, newSILType);
       return castInstr;
     }
   }
@@ -2653,8 +2653,8 @@ bool LoadableByAddress::recreateUncheckedEnumDataInstr(
     auto *takeEnum = enumBuilder.createUncheckedEnumData(
         enumInstr->getLoc(), enumInstr->getOperand(), enumInstr->getElement(),
         caseTy);
-    newInstr = enumBuilder.createUncheckedBitCast(enumInstr->getLoc(), takeEnum,
-                                                  newType);
+    newInstr = enumBuilder.createUncheckedReinterpretCast(enumInstr->getLoc(),
+                                                          takeEnum, newType);
   } else {
     newInstr = enumBuilder.createUncheckedEnumData(
         enumInstr->getLoc(), enumInstr->getOperand(), enumInstr->getElement(),
@@ -2708,7 +2708,7 @@ bool LoadableByAddress::fixStoreToBlockStorageInstr(
   if (destType.getObjectType() != srcType) {
     // Add cast to destType
     SILBuilderWithScope castBuilder(instr);
-    auto *castInstr = castBuilder.createUncheckedBitCast(
+    auto *castInstr = castBuilder.createUncheckedReinterpretCast(
         instr->getLoc(), src, destType.getObjectType());
     instr->setOperand(StoreInst::Src, castInstr);
   }

lib/SIL/IR/SILBuilder.cpp

@@ -141,7 +141,8 @@ SILBuilder::createClassifyBridgeObject(SILLocation Loc, SILValue value) {
 
 // Create the appropriate cast instruction based on result type.
 SingleValueInstruction *
-SILBuilder::createUncheckedBitCast(SILLocation Loc, SILValue Op, SILType Ty) {
+SILBuilder::createUncheckedReinterpretCast(SILLocation Loc, SILValue Op,
+                                           SILType Ty) {
   assert(isLoadableOrOpaque(Ty));
   if (Ty.isTrivial(getFunction()))
     return insert(UncheckedTrivialBitCastInst::create(
@@ -156,6 +157,26 @@ SILBuilder::createUncheckedBitCast(SILLocation Loc, SILValue Op, SILType Ty) {
       getSILDebugLocation(Loc), Op, Ty, getFunction(), C.OpenedArchetypes));
 }
 
+// Create the appropriate cast instruction based on result type.
+SingleValueInstruction *
+SILBuilder::createUncheckedBitCast(SILLocation Loc, SILValue Op, SILType Ty) {
+  // Without ownership, delegate to unchecked reinterpret cast.
+  if (!hasOwnership())
+    return createUncheckedReinterpretCast(Loc, Op, Ty);
+
+  assert(isLoadableOrOpaque(Ty));
+  if (Ty.isTrivial(getFunction()))
+    return insert(UncheckedTrivialBitCastInst::create(
+        getSILDebugLocation(Loc), Op, Ty, getFunction(), C.OpenedArchetypes));
+
+  if (SILType::canRefCast(Op->getType(), Ty, getModule()))
+    return createUncheckedRefCast(Loc, Op, Ty);
+
+  // The destination type is nontrivial, and may be smaller than the source
+  // type, so RC identity cannot be assumed.
+  return createUncheckedValueCast(Loc, Op, Ty);
+}
+
 BranchInst *SILBuilder::createBranch(SILLocation Loc,
                                      SILBasicBlock *TargetBlock,
                                      OperandValueArrayRef Args) {

lib/SILGen/SILGenApply.cpp

@@ -1340,8 +1340,8 @@ class SILGenApply : public Lowering::ExprVisitor<SILGenApply> {
           && loweredResultTy.getASTType()->hasDynamicSelfType()) {
         assert(selfMetaTy);
         selfValue = SGF.emitManagedRValueWithCleanup(
-          SGF.B.createUncheckedBitCast(loc, selfValue.forward(SGF),
-                                       loweredResultTy));
+            SGF.B.createUncheckedReinterpretCast(loc, selfValue.forward(SGF),
+                                                 loweredResultTy));
       } else {
         selfValue = SGF.emitManagedRValueWithCleanup(
             SGF.B.createUpcast(loc, selfValue.forward(SGF), loweredResultTy));

lib/SILGen/SILGenBuilder.cpp

@@ -610,7 +610,7 @@ ManagedValue SILGenBuilder::createUncheckedBitCast(SILLocation loc,
                                                    ManagedValue value,
                                                    SILType type) {
   CleanupCloner cloner(*this, value);
-  SILValue cast = createUncheckedBitCast(loc, value.getValue(), type);
+  SILValue cast = createUncheckedReinterpretCast(loc, value.getValue(), type);
 
   // Currently createUncheckedBitCast only produces these
   // instructions. We assert here to make sure if this changes, this code is

lib/SILGen/SILGenBuilder.h

@@ -279,7 +279,7 @@ class SILGenBuilder : public SILBuilder {
   ManagedValue createUncheckedAddrCast(SILLocation loc, ManagedValue op,
                                        SILType resultTy);
 
-  using SILBuilder::createUncheckedBitCast;
+  using SILBuilder::createUncheckedReinterpretCast;
   ManagedValue createUncheckedBitCast(SILLocation loc, ManagedValue original,
                                       SILType type);
 

lib/SILGen/SILGenExpr.cpp

@@ -2066,8 +2066,8 @@ RValue RValueEmitter::visitUnderlyingToOpaqueExpr(UnderlyingToOpaqueExpr *E,
   if (value.getType() == opaqueTL.getLoweredType())
     return RValue(SGF, E, value);
 
-  auto cast = SGF.B.createUncheckedBitCast(E, value.forward(SGF),
-                                           opaqueTL.getLoweredType());
+  auto cast = SGF.B.createUncheckedReinterpretCast(E, value.forward(SGF),
+                                                   opaqueTL.getLoweredType());
   value = SGF.emitManagedRValueWithCleanup(cast);
 
   return RValue(SGF, E, value);