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[sil-combine] When promoting an unchecked_take_enum_data_addr + load -> load + unchecked_enum_data, make sure to handle the non-trivialness of the operand and the trivialness of the result correctly. #35795

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Merged
merged 1 commit into from
Feb 6, 2021
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[sil-combine] When promoting an unchecked_take_enum_data_addr + load -> load + unchecked_enum_data, make sure to handle the non-trivialness of the operand and the trivialness of the result correctly. #35795

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26 changes: 20 additions & 6 deletions lib/SILOptimizer/SILCombiner/SILCombinerMiscVisitors.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -11,23 +11,25 @@
//===----------------------------------------------------------------------===//

#define DEBUG_TYPE "sil-combine"

#include "SILCombiner.h"
#include "swift/Basic/STLExtras.h"
#include "swift/SIL/DebugUtils.h"
#include "swift/SIL/DynamicCasts.h"
#include "swift/SIL/InstructionUtils.h"
#include "swift/SIL/PatternMatch.h"
#include "swift/SIL/Projection.h"
#include "swift/SIL/SILBitfield.h"
#include "swift/SIL/SILBuilder.h"
#include "swift/SIL/SILInstruction.h"
#include "swift/SIL/SILVisitor.h"
#include "swift/SIL/SILBitfield.h"
#include "swift/SILOptimizer/Analysis/ARCAnalysis.h"
#include "swift/SILOptimizer/Analysis/AliasAnalysis.h"
#include "swift/SILOptimizer/Analysis/ValueTracking.h"
#include "swift/SILOptimizer/Utils/BasicBlockOptUtils.h"
#include "swift/SILOptimizer/Utils/CFGOptUtils.h"
#include "swift/SILOptimizer/Utils/Devirtualize.h"
#include "swift/SILOptimizer/Utils/InstOptUtils.h"
#include "swift/SILOptimizer/Utils/BasicBlockOptUtils.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
Expand Down Expand Up @@ -1764,10 +1766,22 @@ SILInstruction *SILCombiner::visitUncheckedTakeEnumDataAddrInst(
auto *svi = cast<SingleValueInstruction>(user);
SILValue newValue;
if (auto *oldLoad = dyn_cast<LoadInst>(svi)) {
auto newLoad = Builder.emitLoadValueOperation(
loc, enumAddr, oldLoad->getOwnershipQualifier());
newValue =
Builder.createUncheckedEnumData(loc, newLoad, enumElt, payloadType);
// If the old load is trivial and our enum addr is non-trivial, we need to
// use a load_borrow here. We know that the unchecked_enum_data will
// produce a trivial value meaning that we can just do a
// load_borrow/immediately end the lifetime here.
if (oldLoad->getOwnershipQualifier() == LoadOwnershipQualifier::Trivial &&
!enumAddr->getType().isTrivial(Builder.getFunction())) {
Builder.emitScopedBorrowOperation(loc, enumAddr, [&](SILValue newLoad) {
newValue = Builder.createUncheckedEnumData(loc, newLoad, enumElt,
payloadType);
});
} else {
auto newLoad = Builder.emitLoadValueOperation(
loc, enumAddr, oldLoad->getOwnershipQualifier());
newValue =
Builder.createUncheckedEnumData(loc, newLoad, enumElt, payloadType);
}
} else if (auto *lbi = cast<LoadBorrowInst>(svi)) {
auto newLoad = Builder.emitLoadBorrowOperation(loc, enumAddr);
for (auto ui = lbi->consuming_use_begin(), ue = lbi->consuming_use_end();
Expand Down
24 changes: 24 additions & 0 deletions test/SILOptimizer/sil_combine_ossa.sil
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Original file line number Diff line number Diff line change
Expand Up @@ -41,6 +41,12 @@ enum AddressOnlyEnum {
case AddressOnly(Any)
}

enum NonTrivialLoadableEnum {
case noPayload
case trivialPayload(Builtin.Int32)
case nonTrivialPayload(Builtin.NativeObject)
}

protocol FakeProtocol {
func requirement()
}
Expand Down Expand Up @@ -4800,3 +4806,21 @@ bb4:
destroy_value %cast : $Builtin.NativeObject
return %2 : $UInt
}

// CHECK-LABEL: sil [ossa] @unchecked_take_enum_data_addr_promotion_trivialpayload_nontrivial_enum : $@convention(thin) (@inout NonTrivialLoadableEnum) -> Builtin.Int32 {
// CHECK-NOT: unchecked_take_enum_data_addr
// CHECK: unchecked_enum_data
// CHECK-NOT: unchecked_take_enum_data_addr
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maybe a CHECK line with the borrow would have made this more explicit.

// CHECK: } // end sil function 'unchecked_take_enum_data_addr_promotion_trivialpayload_nontrivial_enum'
sil [ossa] @unchecked_take_enum_data_addr_promotion_trivialpayload_nontrivial_enum : $@convention(thin) (@inout NonTrivialLoadableEnum) -> Builtin.Int32 {
bb0(%0 : $*NonTrivialLoadableEnum):
switch_enum_addr %0 : $*NonTrivialLoadableEnum, case #NonTrivialLoadableEnum.trivialPayload!enumelt: bb1, default bb2

bb1:
%2 = unchecked_take_enum_data_addr %0 : $*NonTrivialLoadableEnum, #NonTrivialLoadableEnum.trivialPayload!enumelt
%3 = load [trivial] %2 : $*Builtin.Int32
return %3 : $Builtin.Int32

bb2:
unreachable
}