From 273c299d5d649a0222fbde03c9a41e41913751b4 Mon Sep 17 00:00:00 2001 From: Vedant Kumar Date: Tue, 13 Oct 2020 21:35:29 +0000 Subject: [PM/CC1] Add -f[no-]split-cold-code CC1 option to toggle splitting This patch adds -f[no-]split-cold-code CC1 options to clang. This allows the splitting pass to be toggled on/off. The current method of passing `-mllvm -hot-cold-split=true` to clang isn't ideal as it may not compose correctly (say, with `-O0` or `-Oz`). To implement the -fsplit-cold-code option, an attribute is applied to functions to indicate that they may be considered for splitting. This removes some complexity from the old/new PM pipeline builders, and behaves as expected when LTO is enabled. Co-authored by: Saleem Abdulrasool Differential Revision: https://reviews.llvm.org/D57265 Reviewed By: Aditya Kumar, Vedant Kumar Reviewers: Teresa Johnson, Aditya Kumar, Fedor Sergeev, Philip Pfaffe, Vedant Kumar --- clang/lib/CodeGen/CodeGenModule.cpp | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'clang/lib/CodeGen/CodeGenModule.cpp') diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index 93b49ec981e8..d577dc7d6f5a 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -63,6 +63,7 @@ #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/MD5.h" #include "llvm/Support/TimeProfiler.h" +#include "llvm/Transforms/IPO/HotColdSplitting.h" using namespace clang; using namespace CodeGen; @@ -1695,6 +1696,9 @@ void CodeGenModule::SetLLVMFunctionAttributesForDefinition(const Decl *D, if (D->hasAttr()) B.addAttribute(llvm::Attribute::MinSize); + + if (CodeGenOpts.SplitColdCode) + B.addAttribute(llvm::getHotColdSplittingAttrKind()); } F->addAttributes(llvm::AttributeList::FunctionIndex, B); -- cgit v1.2.3