[llvm] r265765 - Revert "ValueMapper: Treat LocalAsMetadata more like function-local Values"
Duncan P. N. Exon Smith via llvm-commits
llvm-commits at lists.llvm.org
Thu Apr 7 17:56:22 PDT 2016
Author: dexonsmith
Date: Thu Apr 7 19:56:21 2016
New Revision: 265765
URL: http://llvm.org/viewvc/llvm-project?rev=265765&view=rev
Log:
Revert "ValueMapper: Treat LocalAsMetadata more like function-local Values"
This reverts commit r265759, since even this limited version breaks some
bots:
http://lab.llvm.org:8011/builders/clang-ppc64be-linux/builds/3311
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-autoconf/builds/17696
This also reverts r265761 "ValueMapper: Unduplicate
RF_NoModuleLevelChanges check, NFC", since I had trouble separating it
from r265759.
Removed:
llvm/trunk/test/Transforms/Inline/local-as-metadata-undominated-use.ll
Modified:
llvm/trunk/include/llvm/Transforms/Utils/ValueMapper.h
llvm/trunk/lib/IR/Verifier.cpp
llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp
llvm/trunk/unittests/Transforms/Utils/ValueMapperTest.cpp
Modified: llvm/trunk/include/llvm/Transforms/Utils/ValueMapper.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Transforms/Utils/ValueMapper.h?rev=265765&r1=265764&r2=265765&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Transforms/Utils/ValueMapper.h (original)
+++ llvm/trunk/include/llvm/Transforms/Utils/ValueMapper.h Thu Apr 7 19:56:21 2016
@@ -68,21 +68,13 @@ enum RemapFlags {
RF_NoModuleLevelChanges = 1,
/// If this flag is set, the remapper ignores missing function-local entries
- /// (Argument, Instruction, BasicBlock) that are not in the value map. If it
- /// is unset, it aborts if an operand is asked to be remapped which doesn't
- /// exist in the mapping.
+ /// (Argument, Instruction, BasicBlock) that are not in the
+ /// value map. If it is unset, it aborts if an operand is asked to be
+ /// remapped which doesn't exist in the mapping.
///
- /// There are no such assertions in MapValue(), whose results are almost
- /// unchanged by this flag. This flag mainly changes the assertion behaviour
- /// in RemapInstruction().
- ///
- /// Since an Instruction's metadata operands (even that point to SSA values)
- /// aren't guaranteed to be dominated by their definitions, MapMetadata will
- /// return "!{}" instead of "null" for \a LocalAsMetadata instances whose SSA
- /// values are unmapped when this flag is set. Otherwise, \a MapValue()
- /// completely ignores this flag.
- ///
- /// \a MapMetadata() always ignores this flag.
+ /// There are no such assertions in MapValue(), whose result should be
+ /// essentially unchanged by this flag. This only changes the assertion
+ /// behaviour in RemapInstruction().
RF_IgnoreMissingLocals = 2,
/// Instruct the remapper to move distinct metadata instead of duplicating it
@@ -109,32 +101,12 @@ static inline RemapFlags operator|(Remap
/// 3. Else if \c V is a function-local value, return nullptr.
/// 4. Else if \c V is a \a GlobalValue, return \c nullptr or \c V depending
/// on \a RF_NullMapMissingGlobalValues.
-/// 5. Else if \c V is a \a MetadataAsValue wrapping a LocalAsMetadata,
-/// recurse on the local SSA value, and return nullptr or "metadata !{}" on
-/// missing depending on RF_IgnoreMissingValues.
-/// 6. Else if \c V is a \a MetadataAsValue, rewrap the return of \a
-/// MapMetadata().
-/// 7. Else, compute the equivalent constant, and return it.
+/// 5. Else, Compute the equivalent constant, and return it.
Value *MapValue(const Value *V, ValueToValueMapTy &VM,
RemapFlags Flags = RF_None,
ValueMapTypeRemapper *TypeMapper = nullptr,
ValueMaterializer *Materializer = nullptr);
-/// Lookup or compute a mapping for a piece of metadata.
-///
-/// Compute and memoize a mapping for \c MD.
-///
-/// 1. If \c MD is mapped, return it.
-/// 2. Else if \a RF_NoModuleLevelChanges or \c MD is an \a MDString, return
-/// \c MD.
-/// 3. Else if \c MD is a \a ConstantAsMetadata, call \a MapValue() and
-/// re-wrap its return (returning nullptr on nullptr).
-/// 4. Else, \c MD is an \a MDNode. These are remapped, along with their
-/// transitive operands. Distinct nodes are duplicated or moved depending
-/// on \a RF_MoveDistinctNodes. Uniqued nodes are remapped like constants.
-///
-/// \note \a LocalAsMetadata is completely unsupported by \a MapMetadata.
-/// Instead, use \a MapValue() with its wrapping \a MetadataAsValue instance.
Metadata *MapMetadata(const Metadata *MD, ValueToValueMapTy &VM,
RemapFlags Flags = RF_None,
ValueMapTypeRemapper *TypeMapper = nullptr,
Modified: llvm/trunk/lib/IR/Verifier.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Verifier.cpp?rev=265765&r1=265764&r2=265765&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Verifier.cpp (original)
+++ llvm/trunk/lib/IR/Verifier.cpp Thu Apr 7 19:56:21 2016
@@ -3502,10 +3502,6 @@ void Verifier::verifyDominatesUse(Instru
// Quick check whether the def has already been encountered in the same block.
// PHI nodes are not checked to prevent accepting preceeding PHIs, because PHI
// uses are defined to happen on the incoming edge, not at the instruction.
- //
- // FIXME: If this operand is a MetadataAsValue (wrapping a LocalAsMetadata)
- // wrapping an SSA value, assert that we've already encountered it. See
- // related FIXME in Mapper::mapLocalAsMetadata in ValueMapper.cpp.
if (!isa<PHINode>(I) && InstsInThisBlock.count(Op))
return;
Modified: llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp?rev=265765&r1=265764&r2=265765&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/ValueMapper.cpp Thu Apr 7 19:56:21 2016
@@ -86,20 +86,6 @@ public:
/// (not an MDNode, or MDNode::isResolved() returns true).
Metadata *mapMetadata(const Metadata *MD);
- // Map LocalAsMetadata, which never gets memoized.
- //
- // If the referenced local is not mapped, the principled return is nullptr.
- // However, optimization passes sometimes move metadata operands *before* the
- // SSA values they reference. To prevent crashes in \a RemapInstruction(),
- // return "!{}" when RF_IgnoreMissingLocals is not set.
- //
- // \note Adding a mapping for LocalAsMetadata is unsupported. Add a mapping
- // to the value map for the SSA value in question instead.
- //
- // FIXME: Once we have a verifier check for forward references to SSA values
- // through metadata operands, always return nullptr on unmapped locals.
- Metadata *mapLocalAsMetadata(const LocalAsMetadata &LAM);
-
private:
Value *mapBlockAddress(const BlockAddress &BA);
@@ -308,32 +294,18 @@ Value *Mapper::mapValue(const Value *V)
if (const auto *MDV = dyn_cast<MetadataAsValue>(V)) {
const Metadata *MD = MDV->getMetadata();
-
- if (auto *LAM = dyn_cast<LocalAsMetadata>(MD)) {
- // Look through to grab the local value.
- if (Value *LV = mapValue(LAM->getValue())) {
- if (V == LAM->getValue())
- return const_cast<Value *>(V);
- return MetadataAsValue::get(V->getContext(), LocalAsMetadata::get(LV));
- }
-
- // FIXME: always return nullptr once Verifier::verifyDominatesUse()
- // ensures metadata operands only reference defined SSA values.
- return (Flags & RF_IgnoreMissingLocals)
- ? nullptr
- : MetadataAsValue::get(V->getContext(),
- MDTuple::get(V->getContext(), None));
- }
-
// If this is a module-level metadata and we know that nothing at the module
// level is changing, then use an identity mapping.
- if (Flags & RF_NoModuleLevelChanges)
+ if (!isa<LocalAsMetadata>(MD) && (Flags & RF_NoModuleLevelChanges))
return VM[V] = const_cast<Value *>(V);
- // Map the metadata and turn it into a value.
+ // FIXME: be consistent with function-local values for LocalAsMetadata by
+ // returning nullptr when LocalAsMetadata is missing. Adding a mapping is
+ // expensive.
auto *MappedMD = mapMetadata(MD);
- if (MD == MappedMD)
+ if (MD == MappedMD || (!MappedMD && (Flags & RF_IgnoreMissingLocals)))
return VM[V] = const_cast<Value *>(V);
+
return VM[V] = MetadataAsValue::get(V->getContext(), MappedMD);
}
@@ -651,18 +623,21 @@ Optional<Metadata *> Mapper::mapSimpleMe
if (isa<MDString>(MD))
return mapToSelf(MD);
- // This is a module-level metadata. If nothing at the module level is
- // changing, use an identity mapping.
- if ((Flags & RF_NoModuleLevelChanges))
- return mapToSelf(MD);
+ if (isa<ConstantAsMetadata>(MD))
+ if ((Flags & RF_NoModuleLevelChanges))
+ return mapToSelf(MD);
- if (auto *CMD = dyn_cast<ConstantAsMetadata>(MD)) {
+ // FIXME: Assert that this is not LocalAsMetadata. It should be handled
+ // elsewhere.
+ if (const auto *VMD = dyn_cast<ValueAsMetadata>(MD)) {
// Disallow recursion into metadata mapping through mapValue.
VM.disableMapMetadata();
- Value *MappedV = mapValue(CMD->getValue());
+ Value *MappedV = mapValue(VMD->getValue());
VM.enableMapMetadata();
- if (CMD->getValue() == MappedV)
+ // FIXME: Always use "ignore" behaviour. There should only be globals here.
+ if (VMD->getValue() == MappedV ||
+ (!MappedV && (Flags & RF_IgnoreMissingLocals)))
return mapToSelf(MD);
return mapToMetadata(MD, MappedV ? ValueAsMetadata::get(MappedV) : nullptr);
@@ -670,6 +645,11 @@ Optional<Metadata *> Mapper::mapSimpleMe
assert(isa<MDNode>(MD) && "Expected a metadata node");
+ // If this is a module-level metadata and we know that nothing at the
+ // module level is changing, then use an identity mapping.
+ if (Flags & RF_NoModuleLevelChanges)
+ return mapToSelf(MD);
+
return None;
}
@@ -679,26 +659,9 @@ Metadata *llvm::MapMetadata(const Metada
return Mapper(VM, Flags, TypeMapper, Materializer).mapMetadata(MD);
}
-Metadata *Mapper::mapLocalAsMetadata(const LocalAsMetadata &LAM) {
- // Lookup the mapping for the value itself, and return the appropriate
- // metadata.
- if (Value *V = mapValue(LAM.getValue())) {
- if (V == LAM.getValue())
- return const_cast<LocalAsMetadata *>(&LAM);
- return ValueAsMetadata::get(V);
- }
-
- // FIXME: always return nullptr once Verifier::verifyDominatesUse() ensures
- // metadata operands only reference defined SSA values.
- return (Flags & RF_IgnoreMissingLocals)
- ? nullptr
- : MDTuple::get(LAM.getContext(), None);
-}
-
Metadata *Mapper::mapMetadata(const Metadata *MD) {
- assert(MD && "Expected valid metadata");
- assert(!isa<LocalAsMetadata>(MD) && "Unexpected local metadata");
-
+ // FIXME: First check for and deal with LocalAsMetadata, so that
+ // mapSimpleMetadata() doesn't need to deal with it.
if (Optional<Metadata *> NewMD = mapSimpleMetadata(MD))
return *NewMD;
Removed: llvm/trunk/test/Transforms/Inline/local-as-metadata-undominated-use.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Inline/local-as-metadata-undominated-use.ll?rev=265764&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/Inline/local-as-metadata-undominated-use.ll (original)
+++ llvm/trunk/test/Transforms/Inline/local-as-metadata-undominated-use.ll (removed)
@@ -1,49 +0,0 @@
-; RUN: opt -inline -S < %s | FileCheck %s
-
-; Make sure the inliner doesn't crash when a metadata-bridged SSA operand is an
-; undominated use.
-;
-; If we ever add a verifier check to prevent the scenario in this file, it's
-; fine to delete this testcase. However, we would need a bitcode upgrade since
-; such historical IR exists in practice.
-
-define i32 @foo(i32 %i) !dbg !4 {
-entry:
- tail call void @llvm.dbg.value(metadata i32 %add, i64 0, metadata !8, metadata !10), !dbg !11
- %add = add nsw i32 1, %i, !dbg !12
- ret i32 %add, !dbg !13
-}
-
-; CHECK-LABEL: define i32 @caller(
-define i32 @caller(i32 %i) {
-; CHECK-NEXT: entry:
-entry:
-; Although the inliner shouldn't crash, it can't be expected to get the
-; "correct" SSA value since its assumptions have been violated.
-; CHECK-NEXT: tail call void @llvm.dbg.value(metadata ![[EMPTY:[0-9]+]],
-; CHECK-NEXT: %{{.*}} = add nsw
- %call = tail call i32 @foo(i32 %i)
- ret i32 %call
-}
-
-declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
-
-!llvm.dbg.cu = !{!0}
-!llvm.module.flags = !{!9}
-
-!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 3.9.0 (trunk 265634) (llvm/trunk 265637)", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, subprograms: !3)
-!1 = !DIFile(filename: "t.c", directory: "/path/to/tests")
-
-; CHECK: ![[EMPTY]] = !{}
-!2 = !{}
-!3 = !{!4}
-!4 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 2, type: !5, isLocal: false, isDefinition: true, scopeLine: 2, flags: DIFlagPrototyped, isOptimized: true)
-!5 = !DISubroutineType(types: !6)
-!6 = !{!7, !7}
-!7 = !DIBasicType(name: "int", size: 32, align: 32, encoding: DW_ATE_signed)
-!8 = !DILocalVariable(name: "add", arg: 1, scope: !4, file: !1, line: 2, type: !7)
-!9 = !{i32 2, !"Debug Info Version", i32 3}
-!10 = !DIExpression()
-!11 = !DILocation(line: 2, column: 13, scope: !4)
-!12 = !DILocation(line: 2, column: 27, scope: !4)
-!13 = !DILocation(line: 2, column: 18, scope: !4)
Modified: llvm/trunk/unittests/Transforms/Utils/ValueMapperTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/Transforms/Utils/ValueMapperTest.cpp?rev=265765&r1=265764&r2=265765&view=diff
==============================================================================
--- llvm/trunk/unittests/Transforms/Utils/ValueMapperTest.cpp (original)
+++ llvm/trunk/unittests/Transforms/Utils/ValueMapperTest.cpp Thu Apr 7 19:56:21 2016
@@ -139,99 +139,4 @@ TEST(ValueMapperTest, MapMetadataNullMap
EXPECT_EQ(nullptr, MapValue(F.get(), VM, Flags));
}
-TEST(ValueMapperTest, MapMetadataConstantAsMetadata) {
- LLVMContext C;
- FunctionType *FTy =
- FunctionType::get(Type::getVoidTy(C), Type::getInt8Ty(C), false);
- std::unique_ptr<Function> F(
- Function::Create(FTy, GlobalValue::ExternalLinkage, "F"));
-
- auto *CAM = ConstantAsMetadata::get(F.get());
- {
- ValueToValueMapTy VM;
- EXPECT_EQ(CAM, MapMetadata(CAM, VM));
- EXPECT_TRUE(VM.MD().count(CAM));
- VM.MD().erase(CAM);
- EXPECT_EQ(CAM, MapMetadata(CAM, VM, RF_IgnoreMissingLocals));
- EXPECT_TRUE(VM.MD().count(CAM));
-
- auto *N = MDTuple::get(C, None);
- VM.MD()[CAM].reset(N);
- EXPECT_EQ(N, MapMetadata(CAM, VM));
- EXPECT_EQ(N, MapMetadata(CAM, VM, RF_IgnoreMissingLocals));
- }
-
- std::unique_ptr<Function> F2(
- Function::Create(FTy, GlobalValue::ExternalLinkage, "F2"));
- ValueToValueMapTy VM;
- VM[F.get()] = F2.get();
- auto *F2MD = MapMetadata(CAM, VM);
- EXPECT_TRUE(VM.MD().count(CAM));
- EXPECT_TRUE(F2MD);
- EXPECT_EQ(F2.get(), cast<ConstantAsMetadata>(F2MD)->getValue());
-}
-
-#ifdef GTEST_HAS_DEATH_TEST
-#ifndef NDEBUG
-TEST(ValueMapperTest, MapMetadataLocalAsMetadata) {
- LLVMContext C;
- FunctionType *FTy =
- FunctionType::get(Type::getVoidTy(C), Type::getInt8Ty(C), false);
- std::unique_ptr<Function> F(
- Function::Create(FTy, GlobalValue::ExternalLinkage, "F"));
- Argument &A = *F->arg_begin();
-
- // MapMetadata doesn't support LocalAsMetadata. The only valid container for
- // LocalAsMetadata is a MetadataAsValue instance, so use it directly.
- auto *LAM = LocalAsMetadata::get(&A);
- ValueToValueMapTy VM;
- EXPECT_DEATH(MapMetadata(LAM, VM), "Unexpected local metadata");
- EXPECT_DEATH(MapMetadata(LAM, VM, RF_IgnoreMissingLocals),
- "Unexpected local metadata");
-}
-#endif
-#endif
-
-TEST(ValueMapperTest, MapValueLocalAsMetadata) {
- LLVMContext C;
- FunctionType *FTy =
- FunctionType::get(Type::getVoidTy(C), Type::getInt8Ty(C), false);
- std::unique_ptr<Function> F(
- Function::Create(FTy, GlobalValue::ExternalLinkage, "F"));
- Argument &A = *F->arg_begin();
-
- auto *LAM = LocalAsMetadata::get(&A);
- auto *MAV = MetadataAsValue::get(C, LAM);
-
- // The principled answer to a LocalAsMetadata of an unmapped SSA value would
- // be to return nullptr (regardless of RF_IgnoreMissingLocals).
- //
- // However, algorithms that use RemapInstruction assume that each instruction
- // only references SSA values from previous instructions. Arguments of
- // such as "metadata i32 %x" don't currently successfully maintain that
- // property. To keep RemapInstruction from crashing we need a non-null
- // return here, but we also shouldn't reference the unmapped local. Use
- // "metadata !{}".
- auto *N0 = MDTuple::get(C, None);
- auto *N0AV = MetadataAsValue::get(C, N0);
- ValueToValueMapTy VM;
- EXPECT_EQ(N0AV, MapValue(MAV, VM));
- EXPECT_EQ(nullptr, MapValue(MAV, VM, RF_IgnoreMissingLocals));
- EXPECT_FALSE(VM.count(MAV));
- EXPECT_FALSE(VM.count(&A));
- EXPECT_EQ(None, VM.getMappedMD(LAM));
-
- VM[MAV] = MAV;
- EXPECT_EQ(MAV, MapValue(MAV, VM));
- EXPECT_EQ(MAV, MapValue(MAV, VM, RF_IgnoreMissingLocals));
- EXPECT_TRUE(VM.count(MAV));
- EXPECT_FALSE(VM.count(&A));
-
- VM[MAV] = &A;
- EXPECT_EQ(&A, MapValue(MAV, VM));
- EXPECT_EQ(&A, MapValue(MAV, VM, RF_IgnoreMissingLocals));
- EXPECT_TRUE(VM.count(MAV));
- EXPECT_FALSE(VM.count(&A));
-}
-
} // end namespace
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