From 176c7f22172eefddc9ff42dfae8a6015d4e017c6 Mon Sep 17 00:00:00 2001 From: Nikita Popov Date: Fri, 22 Jan 2021 10:38:36 +0100 Subject: [PATCH] [IR] Optimize adding attribute to AttributeList (NFC) When adding an enum attribute to an AttributeList, avoid going through an AttrBuilder and instead directly add the attribute to the correct set. Going through AttrBuilder is expensive, because it requires all string attributes to be reconstructed. This can be further improved by inserting the attribute at the right position and using the AttributeSetNode::getSorted() API. This recovers the small compile-time regression from D94633. --- llvm/include/llvm/IR/Attributes.h | 3 +++ llvm/lib/IR/Attributes.cpp | 29 +++++++++++++++++------------ 2 files changed, 20 insertions(+), 12 deletions(-) diff --git a/llvm/include/llvm/IR/Attributes.h b/llvm/include/llvm/IR/Attributes.h index fbfe585..b405654 100644 --- a/llvm/include/llvm/IR/Attributes.h +++ b/llvm/include/llvm/IR/Attributes.h @@ -399,6 +399,9 @@ private: static AttributeList getImpl(LLVMContext &C, ArrayRef AttrSets); + AttributeList setAttributes(LLVMContext &C, unsigned Index, + AttributeSet Attrs) const; + public: AttributeList() = default; diff --git a/llvm/lib/IR/Attributes.cpp b/llvm/lib/IR/Attributes.cpp index ec2b83f..b17673f 100644 --- a/llvm/lib/IR/Attributes.cpp +++ b/llvm/lib/IR/Attributes.cpp @@ -1272,9 +1272,11 @@ AttributeList AttributeList::get(LLVMContext &C, AttributeList AttributeList::addAttribute(LLVMContext &C, unsigned Index, Attribute::AttrKind Kind) const { if (hasAttribute(Index, Kind)) return *this; - AttrBuilder B; - B.addAttribute(Kind); - return addAttributes(C, Index, B); + AttributeSet Attrs = getAttributes(Index); + // TODO: Insert at correct position and avoid sort. + SmallVector NewAttrs(Attrs.begin(), Attrs.end()); + NewAttrs.push_back(Attribute::get(C, Kind)); + return setAttributes(C, Index, AttributeSet::get(C, NewAttrs)); } AttributeList AttributeList::addAttribute(LLVMContext &C, unsigned Index, @@ -1292,6 +1294,16 @@ AttributeList AttributeList::addAttribute(LLVMContext &C, unsigned Index, return addAttributes(C, Index, B); } +AttributeList AttributeList::setAttributes(LLVMContext &C, unsigned Index, + AttributeSet Attrs) const { + Index = attrIdxToArrayIdx(Index); + SmallVector AttrSets(this->begin(), this->end()); + if (Index >= AttrSets.size()) + AttrSets.resize(Index + 1); + AttrSets[Index] = Attrs; + return AttributeList::getImpl(C, AttrSets); +} + AttributeList AttributeList::addAttributes(LLVMContext &C, unsigned Index, const AttrBuilder &B) const { if (!B.hasAttributes()) @@ -1309,16 +1321,9 @@ AttributeList AttributeList::addAttributes(LLVMContext &C, unsigned Index, "Attempt to change alignment!"); #endif - Index = attrIdxToArrayIdx(Index); - SmallVector AttrSets(this->begin(), this->end()); - if (Index >= AttrSets.size()) - AttrSets.resize(Index + 1); - - AttrBuilder Merged(AttrSets[Index]); + AttrBuilder Merged(getAttributes(Index)); Merged.merge(B); - AttrSets[Index] = AttributeSet::get(C, Merged); - - return getImpl(C, AttrSets); + return setAttributes(C, Index, AttributeSet::get(C, Merged)); } AttributeList AttributeList::addParamAttribute(LLVMContext &C, -- 2.7.4