Merge pull request swiftlang#36174 from meg-gupta/fixcastoptimizer

Fix verifier error in CastOptimizer

Author: meg-gupta

docs/SIL.rst

@@ -3620,6 +3620,20 @@ We require that ``%1`` and ``%0`` have the same type ignoring SILValueCategory.
 
 This instruction is only valid in functions in Ownership SSA form.
 
+end_lifetime
+``````````
+
+::
+
+   sil-instruction ::= 'end_lifetime' sil-operand
+
+This instruction signifies the end of it's operand's lifetime to the ownership
+verifier. It is inserted by the compiler in instances where it could be illegal
+to insert a destroy operation. Ex: if the sil-operand had an undef value.
+
+This instruction is valid only in OSSA and is lowered to a no-op when lowering
+to non-OSSA.
+
 assign
 ``````
 ::

lib/SIL/Verifier/SILVerifier.cpp

@@ -2035,6 +2035,14 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
         "Inst with qualified ownership in a function that is not qualified");
   }
 
+  void checkEndLifetimeInst(EndLifetimeInst *I) {
+    require(!I->getOperand()->getType().isTrivial(*I->getFunction()),
+            "Source value should be non-trivial");
+    require(!fnConv.useLoweredAddresses() || F.hasOwnership(),
+            "end_lifetime is only valid in functions with qualified "
+            "ownership");
+  }
+
   void checkUncheckedValueCastInst(UncheckedValueCastInst *) {
     require(
         F.hasOwnership(),

lib/SILOptimizer/Transforms/PhiArgumentOptimizations.cpp

@@ -165,10 +165,8 @@ bool RedundantPhiEliminationPass::optimizeArgs(SILBasicBlock *block) {
           // arg.
           if (phi1->getOwnershipKind() == OwnershipKind::Owned &&
               phi2->getOwnershipKind() == OwnershipKind::Owned) {
-#ifndef NDEBUG
             assert(hasOnlyNoneOwnershipIncomingValues(phi1));
             assert(hasOnlyNoneOwnershipIncomingValues(phi2));
-#endif
             SILBuilderWithScope builder(&block->front());
             auto copy = builder.createCopyValue(
                 RegularLocation::getAutoGeneratedLocation(), phi1);
@@ -178,18 +176,14 @@ bool RedundantPhiEliminationPass::optimizeArgs(SILBasicBlock *block) {
           // If arg2 has none ownership, replace arg1 with arg2
           else if (phi1->getOwnershipKind() == OwnershipKind::Owned &&
                    phi2->getOwnershipKind() == OwnershipKind::None) {
-#ifndef NDEBUG
             assert(hasOnlyNoneOwnershipIncomingValues(phi1));
-#endif
             phi1->replaceAllUsesWith(phi2);
             eraseOwnedPhiArgument(block, arg1Idx);
           }
           // If arg1 has none ownership, replace arg2 with arg1
           else if (phi1->getOwnershipKind() == OwnershipKind::None &&
                    phi2->getOwnershipKind() == OwnershipKind::Owned) {
-#ifndef NDEBUG
             assert(hasOnlyNoneOwnershipIncomingValues(phi2));
-#endif
             phi2->replaceAllUsesWith(phi1);
             eraseOwnedPhiArgument(block, arg2Idx);
           } else {

lib/SILOptimizer/Utils/CastOptimizer.cpp

@@ -1496,11 +1496,6 @@ void CastOptimizer::deleteInstructionsAfterUnreachable(
   while (UnreachableInstIt != Block->end()) {
     SILInstruction *CurInst = &*UnreachableInstIt;
     ++UnreachableInstIt;
-    if (auto *DeallocStack = dyn_cast<DeallocStackInst>(CurInst))
-      if (!isa<SILUndef>(DeallocStack->getOperand())) {
-        DeallocStack->moveBefore(TrapInst);
-        continue;
-      }
     CurInst->replaceAllUsesOfAllResultsWithUndef();
     eraseInstAction(CurInst);
   }
@@ -1622,17 +1617,6 @@ SILInstruction *CastOptimizer::optimizeUnconditionalCheckedCastAddrInst(
     // Remove the cast and insert a trap, followed by an
     // unreachable instruction.
     SILBuilderWithScope Builder(Inst, builderContext);
-    // mem2reg's invariants get unhappy if we don't try to
-    // initialize a loadable result.
-    if (!dynamicCast.getTargetLoweredType().isAddressOnly(
-            Builder.getFunction())) {
-      auto undef = SILValue(
-          SILUndef::get(dynamicCast.getTargetLoweredType().getObjectType(),
-                        Builder.getFunction()));
-      Builder.emitStoreValueOperation(Loc, undef, dynamicCast.getDest(),
-                                      StoreOwnershipQualifier::Init);
-    }
-    Builder.emitDestroyAddr(Loc, Inst->getSrc());
     auto *TrapI = Builder.createBuiltinTrap(Loc);
     eraseInstAction(Inst);
     Builder.setInsertionPoint(std::next(TrapI->getIterator()));

test/SIL/Parser/basic.sil

@@ -1583,10 +1583,10 @@ bb0(%0 : $Builtin.RawPointer, %1 : $Builtin.Word):
   return %28 : $()
 }
 
-// CHECK-LABEL: sil @test_end_lifetime : $@convention(thin) (@owned Builtin.NativeObject) -> () {
+// CHECK-LABEL: sil [ossa] @test_end_lifetime : $@convention(thin) (@owned Builtin.NativeObject) -> () {
 // CHECK: end_lifetime {{%.*}} : $Builtin.NativeObject
-sil @test_end_lifetime : $@convention(thin) (@owned Builtin.NativeObject) -> () {
-bb0(%0 : $Builtin.NativeObject):
+sil [ossa] @test_end_lifetime : $@convention(thin) (@owned Builtin.NativeObject) -> () {
+bb0(%0 : @owned $Builtin.NativeObject):
   end_lifetime %0 : $Builtin.NativeObject
   return undef : $()
 }

test/SILOptimizer/constant_propagation.sil

@@ -700,8 +700,6 @@ class AnObject {}
 // CHECK-LABEL: sil @replace_unconditional_check_cast_failure
 // CHECK:  bb2:
 // CHECK:  alloc_stack $AnObject
-// CHECK:  store undef to %0
-// CHECK:  dealloc_stack
 // CHECK:  builtin "int_trap"()
 // CHECK:  unreachable
 

test/SILOptimizer/constant_propagation_ownership.sil

@@ -875,8 +875,6 @@ class AnSubObject : AnObject {}
 // CHECK-LABEL: sil [ossa] @replace_unconditional_check_cast_failure
 // CHECK:  bb2:
 // CHECK:  alloc_stack $AnObject
-// CHECK:  store undef to [trivial] %0
-// CHECK:  dealloc_stack
 // CHECK:  builtin "int_trap"()
 // CHECK:  unreachable
 

test/SILOptimizer/sil_combine_uncheck.sil

@@ -38,8 +38,6 @@ bb0(%0 : $Builtin.Int1):
 
 // CHECK-LABEL: sil @test_unconditional_checked_cast_addr_fail
 // CHECK: bb0
-// CHECK-NEXT: store undef
-// CHECK-NEXT: destroy_addr
 // CHECK-NEXT: builtin "int_trap"
 // CHECK: unreachable
 // CHECK: }

test/SILOptimizer/sil_combine_uncheck_ossa.sil

@@ -38,8 +38,6 @@ bb0(%0 : $Builtin.Int1):
 
 // CHECK-LABEL: sil [ossa] @test_unconditional_checked_cast_addr_fail
 // CHECK: bb0
-// CHECK-NEXT: store undef
-// CHECK-NEXT: destroy_addr
 // CHECK-NEXT: builtin "int_trap"
 // CHECK: unreachable
 // CHECK: }