[SIL-opaque] Don't override arg value category.

docs/SIL.rst

@@ -2193,6 +2193,26 @@ parts::
        return %1 : $Klass
      }
 
+Forwarding Address-Only Values
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Address-only values are potentially unmovable when borrowed. This
+means that they cannot be forwarded with guaranteed ownership unless
+the forwarded value has the same representation as in the original
+value and can reuse the same storage. Non-destructive projection is
+allowed, such as `struct_extract`. Aggregation, such as `struct`, and
+destructive disaggregation, such as `switch_enum` is not allowed. This
+is an invariant for OSSA with opaque SIL values for these reasons:
+
+1. To avoid implicit semantic copies. For move-only values, this allows
+complete diagnostics. And in general, it makes it impossible for SIL
+passes to "accidentally" create copies.
+
+2. To reuse borrowed storage. This allows the optimizer to share the same
+storage for multiple exclusive reads of the same variable, avoiding
+copies. It may also be necessary to support native Swift atomics, which
+will be unmovable-when-borrowed.
+
 Borrowed Object based Safe Interior Pointers
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

include/swift/AST/SILOptions.h

@@ -140,6 +140,9 @@ class SILOptions {
   /// If this is disabled we do not serialize in OSSA form when optimizing.
   bool EnableOSSAModules = false;
 
+  /// If set to true, compile with the SIL Opaque Values enabled.
+  bool EnableSILOpaqueValues = false;
+
   // The kind of function bodies to skip emitting.
   FunctionBodySkipping SkipFunctionBodies = FunctionBodySkipping::None;
 

include/swift/Basic/LangOptions.h

@@ -379,11 +379,6 @@ namespace swift {
     /// [TODO: Clang-type-plumbing] Turn on for feature rollout.
     bool UseClangFunctionTypes = false;
 
-    /// If set to true, compile with the SIL Opaque Values enabled.
-    /// This is for bootstrapping. It can't be in SILOptions because the
-    /// TypeChecker uses it to set resolve the ParameterConvention.
-    bool EnableSILOpaqueValues = false;
-
     /// If set to true, the diagnosis engine can assume the emitted diagnostics
     /// will be used in editor. This usually leads to more aggressive fixit.
     bool DiagnosticsEditorMode = false;

include/swift/Option/FrontendOptions.td

@@ -507,9 +507,6 @@ def disable_sil_ownership_verifier : Flag<["-"], "disable-sil-ownership-verifier
 def suppress_static_exclusivity_swap : Flag<["-"], "suppress-static-exclusivity-swap">,
   HelpText<"Suppress static violations of exclusive access with swap()">;
 
-def enable_sil_opaque_values : Flag<["-"], "enable-sil-opaque-values">,
-  HelpText<"Enable SIL Opaque Values">;
-
 def enable_experimental_static_assert :
   Flag<["-"], "enable-experimental-static-assert">,
   HelpText<"Enable experimental #assert">;
@@ -1022,6 +1019,9 @@ def enable_ossa_modules : Flag<["-"], "enable-ossa-modules">,
   HelpText<"Always serialize SIL in ossa form. If this flag is not passed in, "
            "when optimizing ownership will be lowered before serializing SIL">;
 
+def enable_sil_opaque_values : Flag<["-"], "enable-sil-opaque-values">,
+  HelpText<"Enable SIL Opaque Values">;
+
 def new_driver_path
   : Separate<["-"], "new-driver-path">, MetaVarName<"<path>">,
   HelpText<"Path of the new driver to be used">;

include/swift/SIL/ApplySite.h

@@ -585,9 +585,9 @@ class FullApplySite : public ApplySite {
   }
 
   /// Get the SIL value that represents all of the given call's results. For a
-  /// single direct result, returns the result. For multiple results, returns a
-  /// fake tuple value. The tuple has no storage of its own. The real results
-  /// must be extracted from it.
+  /// single direct result, returns the actual result. For multiple results,
+  /// returns a pseudo-result tuple. The tuple has no storage of its own. The
+  /// real results must be extracted from it.
   ///
   /// For ApplyInst, returns the single-value instruction itself.
   ///
@@ -596,7 +596,7 @@ class FullApplySite : public ApplySite {
   /// For BeginApplyInst, returns an invalid value. For coroutines, there is no
   /// single value representing all results. Yielded values are generally
   /// handled differently since they have the convention of incoming arguments.
-  SILValue getPseudoResult() const {
+  SILValue getResult() const {
     switch (getKind()) {
     case FullApplySiteKind::ApplyInst:
       return SILValue(cast<ApplyInst>(getInstruction()));

include/swift/SIL/DynamicCasts.h

@@ -187,14 +187,10 @@ struct SILDynamicCastInst {
     // checked_cast_value_br yet. Should we ever support it, please
     // review this code.
     case SILDynamicCastKind::CheckedCastBranchInst:
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      return CastConsumptionKind::CopyOnSuccess;
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return CastConsumptionKind::TakeAlways;
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return CastConsumptionKind::CopyOnSuccess;
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      llvm_unreachable("unsupported");
     }
     llvm_unreachable("covered switch");
   }
@@ -203,10 +199,8 @@ struct SILDynamicCastInst {
     switch (getKind()) {
     case SILDynamicCastKind::CheckedCastAddrBranchInst:
     case SILDynamicCastKind::CheckedCastBranchInst:
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
       llvm_unreachable("unsupported");
     }
   }
@@ -217,13 +211,9 @@ struct SILDynamicCastInst {
       return cast<CheckedCastAddrBranchInst>(inst)->getSuccessBB();
     case SILDynamicCastKind::CheckedCastBranchInst:
       return cast<CheckedCastBranchInst>(inst)->getSuccessBB();
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      return cast<CheckedCastValueBranchInst>(inst)->getSuccessBB();
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return nullptr;
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      llvm_unreachable("unsupported");
     }
     llvm_unreachable("covered switch");
   }
@@ -234,13 +224,9 @@ struct SILDynamicCastInst {
       llvm_unreachable("unsupported");
     case SILDynamicCastKind::CheckedCastBranchInst:
       return cast<CheckedCastBranchInst>(inst)->getTrueBBCount();
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      llvm_unreachable("unsupported");
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return None;
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      llvm_unreachable("unsupported");
     }
     llvm_unreachable("covered switch");
   }
@@ -255,13 +241,9 @@ struct SILDynamicCastInst {
       return cast<CheckedCastAddrBranchInst>(inst)->getFailureBB();
     case SILDynamicCastKind::CheckedCastBranchInst:
       return cast<CheckedCastBranchInst>(inst)->getFailureBB();
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      return cast<CheckedCastValueBranchInst>(inst)->getFailureBB();
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return nullptr;
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      llvm_unreachable("unsupported");
     }
     llvm_unreachable("covered switch");
   }
@@ -272,13 +254,9 @@ struct SILDynamicCastInst {
       llvm_unreachable("unsupported");
     case SILDynamicCastKind::CheckedCastBranchInst:
       return cast<CheckedCastBranchInst>(inst)->getFalseBBCount();
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      llvm_unreachable("unsupported");
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return None;
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      llvm_unreachable("unsupported");
     }
     llvm_unreachable("covered switch");
   }
@@ -293,14 +271,10 @@ struct SILDynamicCastInst {
       return cast<CheckedCastAddrBranchInst>(inst)->getSrc();
     case SILDynamicCastKind::CheckedCastBranchInst:
       return cast<CheckedCastBranchInst>(inst)->getOperand();
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      return cast<CheckedCastValueBranchInst>(inst)->getOperand();
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return cast<UnconditionalCheckedCastAddrInst>(inst)->getSrc();
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return cast<UnconditionalCheckedCastInst>(inst)->getOperand();
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      llvm_unreachable("unsupported");
     }
     llvm_unreachable("covered switch");
   }
@@ -311,7 +285,6 @@ struct SILDynamicCastInst {
     case SILDynamicCastKind::CheckedCastAddrBranchInst:
       return cast<CheckedCastAddrBranchInst>(inst)->getDest();
     case SILDynamicCastKind::CheckedCastBranchInst:
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
       // TODO: Shouldn't this return getSuccessBlock()->getArgument(0)?
       return SILValue();
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
@@ -321,8 +294,6 @@ struct SILDynamicCastInst {
       //
       // return cast<UnconditionalCheckedCastInst>(inst);
       return SILValue();
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      llvm_unreachable("unimplemented");
     }
     llvm_unreachable("covered switch");
   }
@@ -333,14 +304,10 @@ struct SILDynamicCastInst {
       return cast<CheckedCastAddrBranchInst>(inst)->getSourceFormalType();
     case SILDynamicCastKind::CheckedCastBranchInst:
       return cast<CheckedCastBranchInst>(inst)->getSourceFormalType();
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      return cast<CheckedCastValueBranchInst>(inst)->getSourceFormalType();
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return cast<UnconditionalCheckedCastAddrInst>(inst)->getSourceFormalType();
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return cast<UnconditionalCheckedCastInst>(inst)->getSourceFormalType();
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      return cast<UnconditionalCheckedCastValueInst>(inst)->getSourceFormalType();
     }
     llvm_unreachable("covered switch");
   }
@@ -351,14 +318,10 @@ struct SILDynamicCastInst {
       return cast<CheckedCastAddrBranchInst>(inst)->getSourceLoweredType();
     case SILDynamicCastKind::CheckedCastBranchInst:
       return cast<CheckedCastBranchInst>(inst)->getSourceLoweredType();
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      return cast<CheckedCastValueBranchInst>(inst)->getSourceLoweredType();
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return cast<UnconditionalCheckedCastAddrInst>(inst)->getSourceLoweredType();
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return cast<UnconditionalCheckedCastInst>(inst)->getSourceLoweredType();
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      return cast<UnconditionalCheckedCastValueInst>(inst)->getSourceLoweredType();
     }
     llvm_unreachable("covered switch");
   }
@@ -369,14 +332,10 @@ struct SILDynamicCastInst {
       return cast<CheckedCastAddrBranchInst>(inst)->getTargetFormalType();
     case SILDynamicCastKind::CheckedCastBranchInst:
       return cast<CheckedCastBranchInst>(inst)->getTargetFormalType();
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      return cast<CheckedCastValueBranchInst>(inst)->getTargetFormalType();
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return cast<UnconditionalCheckedCastAddrInst>(inst)->getTargetFormalType();
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return cast<UnconditionalCheckedCastInst>(inst)->getTargetFormalType();
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      return cast<UnconditionalCheckedCastValueInst>(inst)->getTargetFormalType();
     }
     llvm_unreachable("covered switch");
   }
@@ -387,28 +346,21 @@ struct SILDynamicCastInst {
       return cast<CheckedCastAddrBranchInst>(inst)->getDest()->getType();
     case SILDynamicCastKind::CheckedCastBranchInst:
       return cast<CheckedCastBranchInst>(inst)->getTargetLoweredType();
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
-      return cast<CheckedCastValueBranchInst>(inst)->getTargetLoweredType();
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
       return cast<UnconditionalCheckedCastAddrInst>(inst)->getDest()->getType();
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return cast<UnconditionalCheckedCastInst>(inst)->getTargetLoweredType();
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      return cast<UnconditionalCheckedCastValueInst>(inst)->getTargetLoweredType();
     }
     llvm_unreachable("covered switch");
   }
 
   bool isSourceTypeExact() const {
     switch (getKind()) {
-    case SILDynamicCastKind::CheckedCastValueBranchInst:
     case SILDynamicCastKind::CheckedCastBranchInst:
     case SILDynamicCastKind::CheckedCastAddrBranchInst:
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return isa<MetatypeInst>(getSource());
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      llvm_unreachable("unsupported");
     }
     llvm_unreachable("covered switch");
   }
@@ -476,15 +428,9 @@ struct SILDynamicCastInst {
       auto f = classifyFeasibility(false /*allow wmo*/);
       return f == DynamicCastFeasibility::MaySucceed;
     }
-    case SILDynamicCastKind::CheckedCastValueBranchInst: {
-      auto f = classifyFeasibility(false /*allow wmo opts*/);
-      return f == DynamicCastFeasibility::MaySucceed;
-    }
     case SILDynamicCastKind::UnconditionalCheckedCastAddrInst:
     case SILDynamicCastKind::UnconditionalCheckedCastInst:
       return false;
-    case SILDynamicCastKind::UnconditionalCheckedCastValueInst:
-      llvm_unreachable("unsupported");
     }
     llvm_unreachable("covered switch");
   }

include/swift/SIL/SILBuilder.h

@@ -266,11 +266,10 @@ class SILBuilder {
   void clearInsertionPoint() { BB = nullptr; }
 
   /// setInsertionPoint - Set the insertion point.
-  void setInsertionPoint(SILBasicBlock *BB, SILBasicBlock::iterator InsertPt) {
+  void setInsertionPoint(SILBasicBlock *BB, SILBasicBlock::iterator insertPt) {
     this->BB = BB;
-    this->InsertPt = InsertPt;
-    if (InsertPt == BB->end())
-      return;
+    this->InsertPt = insertPt;
+    assert(insertPt == BB->end() || insertPt->getParent() == BB);
   }
 
   /// setInsertionPoint - Set the insertion point to insert before the specified
@@ -1315,16 +1314,6 @@ class SILBuilder {
         dest, targetFormalType, getFunction()));
   }
 
-  UnconditionalCheckedCastValueInst *
-  createUnconditionalCheckedCastValue(SILLocation Loc,
-                                      SILValue op, CanType srcFormalTy,
-                                      SILType destLoweredTy,
-                                      CanType destFormalTy) {
-    return insert(UnconditionalCheckedCastValueInst::create(
-        getSILDebugLocation(Loc), op, srcFormalTy,
-        destLoweredTy, destFormalTy, getFunction()));
-  }
-
   RetainValueInst *createRetainValue(SILLocation Loc, SILValue operand,
                                      Atomicity atomicity) {
     assert(!hasOwnership());
@@ -2325,18 +2314,6 @@ class SILBuilder {
                           ProfileCounter Target1Count = ProfileCounter(),
                           ProfileCounter Target2Count = ProfileCounter());
 
-  CheckedCastValueBranchInst *
-  createCheckedCastValueBranch(SILLocation Loc,
-                               SILValue op, CanType srcFormalTy,
-                               SILType destLoweredTy,
-                               CanType destFormalTy,
-                               SILBasicBlock *successBB,
-                               SILBasicBlock *failureBB) {
-    return insertTerminator(CheckedCastValueBranchInst::create(
-        getSILDebugLocation(Loc), op, srcFormalTy,
-        destLoweredTy, destFormalTy, successBB, failureBB, getFunction()));
-  }
-
   CheckedCastAddrBranchInst *
   createCheckedCastAddrBranch(SILLocation Loc, CastConsumptionKind consumption,
                               SILValue src, CanType sourceFormalType,

include/swift/SIL/SILCloner.h

@@ -1706,24 +1706,6 @@ SILCloner<ImplClass>::visitUnconditionalCheckedCastAddrInst(
                               OpLoc, SrcValue, SrcType, DestValue, TargetType));
 }
 
-template <typename ImplClass>
-void SILCloner<ImplClass>::visitUnconditionalCheckedCastValueInst(
-    UnconditionalCheckedCastValueInst *Inst) {
-  SILLocation OpLoc = getOpLocation(Inst->getLoc());
-  SILValue OpValue = getOpValue(Inst->getOperand());
-  CanType SrcFormalType = getOpASTType(Inst->getSourceFormalType());
-  SILType OpLoweredType = getOpType(Inst->getTargetLoweredType());
-  CanType OpFormalType = getOpASTType(Inst->getTargetFormalType());
-  getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
-  recordClonedInstruction(
-      Inst,
-      getBuilder().createUnconditionalCheckedCastValue(OpLoc,
-                                                       OpValue,
-                                                       SrcFormalType,
-                                                       OpLoweredType,
-                                                       OpFormalType));
-}
-
 template <typename ImplClass>
 void SILCloner<ImplClass>::visitRetainValueInst(RetainValueInst *Inst) {
   getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
@@ -2737,22 +2719,6 @@ SILCloner<ImplClass>::visitCheckedCastBranchInst(CheckedCastBranchInst *Inst) {
                 Inst->getForwardingOwnershipKind(), TrueCount, FalseCount));
 }
 
-template <typename ImplClass>
-void SILCloner<ImplClass>::visitCheckedCastValueBranchInst(
-    CheckedCastValueBranchInst *Inst) {
-  SILBasicBlock *OpSuccBB = getOpBasicBlock(Inst->getSuccessBB());
-  SILBasicBlock *OpFailBB = getOpBasicBlock(Inst->getFailureBB());
-  getBuilder().setCurrentDebugScope(getOpScope(Inst->getDebugScope()));
-  recordClonedInstruction(
-      Inst, getBuilder().createCheckedCastValueBranch(
-                getOpLocation(Inst->getLoc()),
-                getOpValue(Inst->getOperand()),
-                getOpASTType(Inst->getSourceFormalType()),
-                getOpType(Inst->getTargetLoweredType()),
-                getOpASTType(Inst->getTargetFormalType()),
-                OpSuccBB, OpFailBB));
-}
-
 template<typename ImplClass>
 void SILCloner<ImplClass>::visitCheckedCastAddrBranchInst(
                                              CheckedCastAddrBranchInst *Inst) {