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.
llvm-svn: 265765
diff --git a/llvm/lib/Transforms/Utils/ValueMapper.cpp b/llvm/lib/Transforms/Utils/ValueMapper.cpp
index 27c7f1b..59870f8 100644
--- a/llvm/lib/Transforms/Utils/ValueMapper.cpp
+++ b/llvm/lib/Transforms/Utils/ValueMapper.cpp
@@ -86,20 +86,6 @@
/// (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 @@
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 @@
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 @@
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 @@
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;