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[Attributor][NFCI] Move attribute collection and manifest to Attributor
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Before, we checked and manifested attributes right in the IR. This was
bad as we modified the IR before the manifest stage. Now we can
add/remove/inspect attributes w/o going to the IR (except for the
initial query).
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@jdoerfert
jdoerfert committed Jul 3, 2023
1 parent 77dbd1d commit f086f38
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Showing 4 changed files with 308 additions and 254 deletions.
127 changes: 59 additions & 68 deletions llvm/include/llvm/Transforms/IPO/Attributor.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -821,6 +821,13 @@ struct IRPosition {
"There is no attribute index for a floating or invalid position!");
}

/// Return the value attributes are attached to.
Value *getAttrListAnchor() const {
if (auto *CB = dyn_cast<CallBase>(&getAnchorValue()))
return CB;
return getAssociatedFunction();
}

/// Return the attributes associated with this function or call site scope.
AttributeList getAttrList() const {
if (auto *CB = dyn_cast<CallBase>(&getAnchorValue()))
Expand Down Expand Up @@ -878,51 +885,6 @@ struct IRPosition {
return IRP_FLOAT;
}

/// TODO: Figure out if the attribute related helper functions should live
/// here or somewhere else.

/// Return true if any kind in \p AKs existing in the IR at a position that
/// will affect this one. See also getAttrs(...).
/// \param IgnoreSubsumingPositions Flag to determine if subsuming positions,
/// e.g., the function position if this is an
/// argument position, should be ignored.
bool hasAttr(ArrayRef<Attribute::AttrKind> AKs,
bool IgnoreSubsumingPositions = false,
Attributor *A = nullptr) const;

/// Return the attributes of any kind in \p AKs existing in the IR at a
/// position that will affect this one. While each position can only have a
/// single attribute of any kind in \p AKs, there are "subsuming" positions
/// that could have an attribute as well. This method returns all attributes
/// found in \p Attrs.
/// \param IgnoreSubsumingPositions Flag to determine if subsuming positions,
/// e.g., the function position if this is an
/// argument position, should be ignored.
void getAttrs(ArrayRef<Attribute::AttrKind> AKs,
SmallVectorImpl<Attribute> &Attrs,
bool IgnoreSubsumingPositions = false,
Attributor *A = nullptr) const;

/// Remove the attribute of kind \p AKs existing in the IR at this position.
void removeAttrs(ArrayRef<Attribute::AttrKind> AKs) const {
if (getPositionKind() == IRP_INVALID || getPositionKind() == IRP_FLOAT)
return;

AttributeList AttrList = getAttrList();

bool Changed = false;
unsigned Idx = getAttrIdx();
LLVMContext &Ctx = getAnchorValue().getContext();
for (Attribute::AttrKind AK : AKs) {
if (!AttrList.hasAttributeAtIndex(Idx, AK))
continue;
Changed = true;
AttrList = AttrList.removeAttributeAtIndex(Ctx, Idx, AK);
}
if (Changed)
setAttrList(AttrList);
}

bool isAnyCallSitePosition() const {
switch (getPositionKind()) {
case IRPosition::IRP_CALL_SITE:
Expand Down Expand Up @@ -1041,16 +1003,6 @@ struct IRPosition {
/// Verify internal invariants.
void verify();

/// Return the attributes of kind \p AK existing in the IR as attribute.
bool getAttrsFromIRAttr(Attribute::AttrKind AK,
SmallVectorImpl<Attribute> &Attrs) const;

/// Return the attributes of kind \p AK existing in the IR as operand bundles
/// of an llvm.assume.
bool getAttrsFromAssumes(Attribute::AttrKind AK,
SmallVectorImpl<Attribute> &Attrs,
Attributor &A) const;

/// Return the underlying pointer as Value *, valid for all positions but
/// IRP_CALL_SITE_ARGUMENT.
Value *getAsValuePtr() const {
Expand Down Expand Up @@ -1893,6 +1845,52 @@ struct Attributor {
ToBeDeletedFunctions.insert(&F);
}

/// Return the attributes of kind \p AK existing in the IR as operand bundles
/// of an llvm.assume.
bool getAttrsFromAssumes(const IRPosition &IRP, Attribute::AttrKind AK,
SmallVectorImpl<Attribute> &Attrs);

/// Return true if any kind in \p AKs existing in the IR at a position that
/// will affect this one. See also getAttrs(...).
/// \param IgnoreSubsumingPositions Flag to determine if subsuming positions,
/// e.g., the function position if this is an
/// argument position, should be ignored.
bool hasAttr(const IRPosition &IRP, ArrayRef<Attribute::AttrKind> AKs,
bool IgnoreSubsumingPositions = false,
Attribute::AttrKind ImpliedAttributeKind = Attribute::None);

/// Return the attributes of any kind in \p AKs existing in the IR at a
/// position that will affect this one. While each position can only have a
/// single attribute of any kind in \p AKs, there are "subsuming" positions
/// that could have an attribute as well. This method returns all attributes
/// found in \p Attrs.
/// \param IgnoreSubsumingPositions Flag to determine if subsuming positions,
/// e.g., the function position if this is an
/// argument position, should be ignored.
void getAttrs(const IRPosition &IRP, ArrayRef<Attribute::AttrKind> AKs,
SmallVectorImpl<Attribute> &Attrs,
bool IgnoreSubsumingPositions = false);

ChangeStatus removeAttrs(const IRPosition &IRP,
const ArrayRef<Attribute::AttrKind> &AttrKinds);

ChangeStatus manifestAttrs(const IRPosition &IRP,
const ArrayRef<Attribute> &DeducedAttrs,
bool ForceReplace = false);

private:
/// Helper to apply \p CB on all attributes of type \p AttrDescs of \p IRP.
template <typename DescTy>
ChangeStatus updateAttrMap(const IRPosition &IRP,
const ArrayRef<DescTy> &AttrDescs,
function_ref<bool(const DescTy &, AttributeSet,
AttributeMask &, AttrBuilder &)>
CB);

/// Mapping from functions/call sites to their attributes.
DenseMap<Value *, AttributeList> AttrsMap;

public:
/// If \p IRP is assumed to be a constant, return it, if it is unclear yet,
/// return std::nullopt, otherwise return `nullptr`.
std::optional<Constant *> getAssumedConstant(const IRPosition &IRP,
Expand Down Expand Up @@ -3095,14 +3093,6 @@ template <typename BaseTy> struct SetState : public AbstractState {
bool IsAtFixedpoint;
};

/// Helper struct necessary as the modular build fails if the virtual method
/// IRAttribute::manifest is defined in the Attributor.cpp.
struct IRAttributeManifest {
static ChangeStatus manifestAttrs(Attributor &A, const IRPosition &IRP,
const ArrayRef<Attribute> &DeducedAttrs,
bool ForceReplace = false);
};

/// Helper to tie a abstract state implementation to an abstract attribute.
template <typename StateTy, typename BaseType, class... Ts>
struct StateWrapper : public BaseType, public StateTy {
Expand All @@ -3129,7 +3119,7 @@ struct IRAttribute : public BaseType {
bool IgnoreSubsumingPositions = false) {
if (isa<UndefValue>(IRP.getAssociatedValue()))
return true;
return IRP.hasAttr(AttrKinds, IgnoreSubsumingPositions, &A);
return A.hasAttr(IRP, AttrKinds, IgnoreSubsumingPositions);
}

/// See AbstractAttribute::initialize(...).
Expand All @@ -3147,8 +3137,9 @@ struct IRAttribute : public BaseType {
return ChangeStatus::UNCHANGED;
SmallVector<Attribute, 4> DeducedAttrs;
getDeducedAttributes(this->getAnchorValue().getContext(), DeducedAttrs);
return IRAttributeManifest::manifestAttrs(A, this->getIRPosition(),
DeducedAttrs);
if (DeducedAttrs.empty())
return ChangeStatus::UNCHANGED;
return A.manifestAttrs(this->getIRPosition(), DeducedAttrs);
}

/// Return the kind that identifies the abstract attribute implementation.
Expand Down Expand Up @@ -3627,8 +3618,8 @@ struct AAWillReturn
return false;

SmallVector<Attribute, 1> Attrs;
IRP.getAttrs({Attribute::Memory}, Attrs,
/* IgnoreSubsumingPositions */ false);
A.getAttrs(IRP, {Attribute::Memory}, Attrs,
/* IgnoreSubsumingPositions */ false);

MemoryEffects ME = MemoryEffects::unknown();
for (const Attribute &Attr : Attrs)
Expand Down
14 changes: 7 additions & 7 deletions llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
View file
Original file line number Diff line number Diff line change
Expand Up @@ -368,8 +368,8 @@ struct AAUniformWorkGroupSizeFunction : public AAUniformWorkGroupSize {

AttrList.push_back(Attribute::get(Ctx, "uniform-work-group-size",
getAssumed() ? "true" : "false"));
return IRAttributeManifest::manifestAttrs(A, getIRPosition(), AttrList,
/* ForceReplace */ true);
return A.manifestAttrs(getIRPosition(), AttrList,
/* ForceReplace */ true);
}

bool isValidState() const override {
Expand Down Expand Up @@ -526,8 +526,8 @@ struct AAAMDAttributesFunction : public AAAMDAttributes {
AttrList.push_back(Attribute::get(Ctx, Attr.second));
}

return IRAttributeManifest::manifestAttrs(A, getIRPosition(), AttrList,
/* ForceReplace */ true);
return A.manifestAttrs(getIRPosition(), AttrList,
/* ForceReplace */ true);
}

const std::string getAsStr() const override {
Expand Down Expand Up @@ -732,9 +732,9 @@ struct AAAMDSizeRangeAttribute
SmallString<10> Buffer;
raw_svector_ostream OS(Buffer);
OS << getAssumed().getLower() << ',' << getAssumed().getUpper() - 1;
return IRAttributeManifest::manifestAttrs(
A, getIRPosition(), {Attribute::get(Ctx, AttrName, OS.str())},
/* ForceReplace */ true);
return A.manifestAttrs(getIRPosition(),
{Attribute::get(Ctx, AttrName, OS.str())},
/* ForceReplace */ true);
}

const std::string getAsStr() const override {
Expand Down

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