diff options
author | Dimitry Andric <dim@FreeBSD.org> | 2015-06-21 13:59:01 +0000 |
---|---|---|
committer | Dimitry Andric <dim@FreeBSD.org> | 2015-06-21 13:59:01 +0000 |
commit | 3a0822f094b578157263e04114075ad7df81db41 (patch) | |
tree | bc48361fe2cd1ca5f93ac01b38b183774468fc79 /lib/Transforms/IPO/ArgumentPromotion.cpp | |
parent | 85d8b2bbe386bcfe669575d05b61482d7be07e5d (diff) | |
download | src-3a0822f094b578157263e04114075ad7df81db41.tar.gz src-3a0822f094b578157263e04114075ad7df81db41.zip |
Vendor import of llvm trunk r240225:vendor/llvm/llvm-trunk-r240225
Notes
Notes:
svn path=/vendor/llvm/dist/; revision=284677
svn path=/vendor/llvm/llvm-trunk-r240225/; revision=284678; tag=vendor/llvm/llvm-trunk-r240225
Diffstat (limited to 'lib/Transforms/IPO/ArgumentPromotion.cpp')
-rw-r--r-- | lib/Transforms/IPO/ArgumentPromotion.cpp | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/lib/Transforms/IPO/ArgumentPromotion.cpp b/lib/Transforms/IPO/ArgumentPromotion.cpp index c7c57ab56444..86b3faa09b9c 100644 --- a/lib/Transforms/IPO/ArgumentPromotion.cpp +++ b/lib/Transforms/IPO/ArgumentPromotion.cpp @@ -92,7 +92,7 @@ namespace { unsigned maxElements; DenseMap<const Function *, DISubprogram *> FunctionDIs; }; -} +} // namespace char ArgPromotion::ID = 0; INITIALIZE_PASS_BEGIN(ArgPromotion, "argpromotion", @@ -245,6 +245,24 @@ CallGraphNode *ArgPromotion::PromoteArguments(CallGraphNode *CGN) { Argument *PtrArg = PointerArgs[i]; Type *AgTy = cast<PointerType>(PtrArg->getType())->getElementType(); + // Replace sret attribute with noalias. This reduces register pressure by + // avoiding a register copy. + if (PtrArg->hasStructRetAttr()) { + unsigned ArgNo = PtrArg->getArgNo(); + F->setAttributes( + F->getAttributes() + .removeAttribute(F->getContext(), ArgNo + 1, Attribute::StructRet) + .addAttribute(F->getContext(), ArgNo + 1, Attribute::NoAlias)); + for (Use &U : F->uses()) { + CallSite CS(U.getUser()); + CS.setAttributes( + CS.getAttributes() + .removeAttribute(F->getContext(), ArgNo + 1, + Attribute::StructRet) + .addAttribute(F->getContext(), ArgNo + 1, Attribute::NoAlias)); + } + } + // If this is a byval argument, and if the aggregate type is small, just // pass the elements, which is always safe, if the passed value is densely // packed or if we can prove the padding bytes are never accessed. This does @@ -553,7 +571,7 @@ bool ArgPromotion::isSafeToPromoteArgument(Argument *Arg, LoadInst *Load = Loads[i]; BasicBlock *BB = Load->getParent(); - AliasAnalysis::Location Loc = MemoryLocation::get(Load); + MemoryLocation Loc = MemoryLocation::get(Load); if (AA.canInstructionRangeModRef(BB->front(), *Load, Loc, AliasAnalysis::Mod)) return false; // Pointer is invalidated! |