[cast-opt] Update optimization of unconditional checked cast to use SILDynamicCastInst.

Author: gottesmm

include/swift/SIL/DynamicCasts.h

@@ -63,6 +63,9 @@ DynamicCastFeasibility classifyDynamicCast(
     bool isSourceTypeExact = false,
     bool isWholdModuleOpts = false);
 
+SILValue emitSuccessfulScalarUnconditionalCast(SILBuilder &B, SILLocation loc,
+                                               SILDynamicCastInst inst);
+
 SILValue emitSuccessfulScalarUnconditionalCast(
     SILBuilder &B, ModuleDecl *M, SILLocation loc, SILValue value,
     SILType loweredTargetType,
@@ -186,6 +189,7 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return CastConsumptionKind::TakeAlways;
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      return CastConsumptionKind::CopyOnSuccess;
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }
@@ -210,8 +214,8 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::CheckedCastValueBranchInst:
       llvm_unreachable("unsupported");
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
-      return nullptr;
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      return nullptr;
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }
@@ -228,8 +232,8 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::CheckedCastValueBranchInst:
       llvm_unreachable("unsupported");
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
-      return nullptr;
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      return nullptr;
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }
@@ -248,6 +252,7 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return cast<UnconditionalCheckedCastAddrInst>(inst)->getSrc();
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      return cast<UnconditionalCheckedCastInst>(inst)->getOperand();
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }
@@ -263,6 +268,10 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return cast<UnconditionalCheckedCastAddrInst>(inst)->getDest();
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      // TODO: Why isn't this:
+      //
+      // return cast<UnconditionalCheckedCastInst>(inst);
+      return SILValue();
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unimplemented");
     }
@@ -277,6 +286,7 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return cast<UnconditionalCheckedCastAddrInst>(inst)->getSourceType();
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      return cast<UnconditionalCheckedCastInst>(inst)->getSourceType();
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }
@@ -293,6 +303,7 @@ struct SILDynamicCastInst {
       return uccai->getSrc()->getType();
     }
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      return cast<UnconditionalCheckedCastInst>(inst)->getOperand()->getType();
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }
@@ -307,6 +318,7 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return cast<UnconditionalCheckedCastAddrInst>(inst)->getTargetType();
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      return cast<UnconditionalCheckedCastInst>(inst)->getTargetType();
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unimplemented");
     }
@@ -322,7 +334,9 @@ struct SILDynamicCastInst {
       auto *uccai = dyn_cast<UnconditionalCheckedCastAddrInst>(inst);
       return uccai->getDest()->getType();
     }
-    case SILDynamicCastKind::UnconditionalCheckedCastInst:
+    case SILDynamicCastKind::UnconditionalCheckedCastInst: {
+      return cast<UnconditionalCheckedCastInst>(inst)->getType();
+    }
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }
@@ -335,8 +349,8 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::CheckedCastValueBranchInst:
       llvm_unreachable("unsupported");
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
-      return isa<MetatypeInst>(getSource());
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      return isa<MetatypeInst>(getSource());
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }
@@ -368,8 +382,8 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::CheckedCastValueBranchInst:
       llvm_unreachable("unsupported");
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
-      return false;
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
+      return false;
     case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }

lib/SIL/DynamicCasts.cpp

@@ -1036,6 +1036,15 @@ namespace {
   };
 } // end anonymous namespace
 
+SILValue
+swift::emitSuccessfulScalarUnconditionalCast(SILBuilder &B, SILLocation loc,
+                                             SILDynamicCastInst dynamicCast) {
+  return emitSuccessfulScalarUnconditionalCast(
+      B, B.getModule().getSwiftModule(), loc, dynamicCast.getSource(),
+      dynamicCast.getLoweredTargetType(), dynamicCast.getSourceType(),
+      dynamicCast.getTargetType(), dynamicCast.getInstruction());
+}
+
 /// Emit an unconditional scalar cast that's known to succeed.
 SILValue
 swift::emitSuccessfulScalarUnconditionalCast(SILBuilder &B, ModuleDecl *M,

lib/SILOptimizer/Utils/CastOptimizer.cpp

@@ -45,19 +45,6 @@
 
 using namespace swift;
 
-/// Check if is a bridging cast, i.e. one of the sides is
-/// a bridged type.
-static bool isBridgingCast(CanType SourceType, CanType TargetType) {
-  // Bridging casts cannot be further simplified.
-  auto TargetIsBridgeable = TargetType->isBridgeableObjectType();
-  auto SourceIsBridgeable = SourceType->isBridgeableObjectType();
-
-  if (TargetIsBridgeable != SourceIsBridgeable)
-    return true;
-
-  return false;
-}
-
 /// If target is a Swift type bridging to an ObjC type,
 /// return the ObjC type it bridges to.
 /// If target is an ObjC type, return this type.
@@ -1270,18 +1257,12 @@ CastOptimizer::optimizeCheckedCastBranchInst(CheckedCastBranchInst *Inst) {
 
 ValueBase *CastOptimizer::optimizeUnconditionalCheckedCastInst(
     UnconditionalCheckedCastInst *Inst) {
-  auto LoweredSourceType = Inst->getOperand()->getType();
-  auto LoweredTargetType = Inst->getType();
-  auto Loc = Inst->getLoc();
-  auto Op = Inst->getOperand();
-  auto &Mod = Inst->getModule();
-
-  bool isSourceTypeExact = isa<MetatypeInst>(Op);
+  SILDynamicCastInst dynamicCast(Inst);
+  auto Loc = dynamicCast.getLocation();
 
   // Check if we can statically predict the outcome of the cast.
   auto Feasibility =
-      classifyDynamicCast(Mod.getSwiftModule(), Inst->getSourceType(),
-                          Inst->getTargetType(), isSourceTypeExact);
+      dynamicCast.classifyFeasibility(false /*allowWholeModule*/);
 
   if (Feasibility == DynamicCastFeasibility::WillFail) {
     // Remove the cast and insert a trap, followed by an
@@ -1314,12 +1295,7 @@ ValueBase *CastOptimizer::optimizeUnconditionalCheckedCastInst(
   SILBuilderWithScope Builder(Inst, BuilderContext);
 
   // Try to apply the bridged casts optimizations
-  auto SourceType = LoweredSourceType.getASTType();
-  auto TargetType = LoweredTargetType.getASTType();
-  auto Src = Inst->getOperand();
-  auto NewI = optimizeBridgedCasts(Inst, CastConsumptionKind::CopyOnSuccess,
-                                   false, Src, SILValue(), SourceType,
-                                   TargetType, nullptr, nullptr);
+  auto NewI = optimizeBridgedCasts(dynamicCast);
   if (NewI) {
     // FIXME: I'm not sure why this is true!
     auto newValue = cast<SingleValueInstruction>(NewI);
@@ -1337,13 +1313,11 @@ ValueBase *CastOptimizer::optimizeUnconditionalCheckedCastInst(
 
   assert(Feasibility == DynamicCastFeasibility::WillSucceed);
 
-  if (isBridgingCast(SourceType, TargetType))
+  if (dynamicCast.isBridgingCast())
     return nullptr;
 
-  auto Result = emitSuccessfulScalarUnconditionalCast(
-      Builder, Mod.getSwiftModule(), Loc, Op, LoweredTargetType,
-      LoweredSourceType.getASTType(),
-      LoweredTargetType.getASTType(), Inst);
+  auto Result =
+      emitSuccessfulScalarUnconditionalCast(Builder, Loc, dynamicCast);
 
   if (!Result) {
     // No optimization was possible.