CodeGen, Target: Move Mach-O-specific symbol name logic to Mach-O lowering.

A profile of an LTO link of Chrome revealed that we were spending some
~30-50% of execution time in the function Constant::getRelocationInfo(),
which is called from TargetLoweringObjectFile::getKindForGlobal() and in turn
from TargetMachine::getNameWithPrefix().

It turns out that we only need the result of getKindForGlobal() when
targeting Mach-O, so this change moves the relevant part of the logic to
TargetLoweringObjectFileMachO.

NFCI.

Differential Revision: http://reviews.llvm.org/D14168

llvm-svn: 252014

1 files changed, 1 insertions, 17 deletions

diff --git a/llvm/lib/Target/TargetMachine.cpp b/llvm/lib/Target/TargetMachine.cpp
index 6dc3b97fc98..850c93cb21b 100644
--- a/llvm/lib/Target/TargetMachine.cpp
+++ b/llvm/lib/Target/TargetMachine.cpp
@@ -155,19 +155,6 @@ TargetIRAnalysis TargetMachine::getTargetIRAnalysis() {
   });
 }
 
-static bool canUsePrivateLabel(const MCAsmInfo &AsmInfo,
-                               const MCSection &Section) {
-  if (!AsmInfo.isSectionAtomizableBySymbols(Section))
-    return true;
-
-  // If it is not dead stripped, it is safe to use private labels.
-  const MCSectionMachO &SMO = cast<MCSectionMachO>(Section);
-  if (SMO.hasAttribute(MachO::S_ATTR_NO_DEAD_STRIP))
-    return true;
-
-  return false;
-}
-
 void TargetMachine::getNameWithPrefix(SmallVectorImpl<char> &Name,
                                       const GlobalValue *GV, Mangler &Mang,
                                       bool MayAlwaysUsePrivate) const {
@@ -177,11 +164,8 @@ void TargetMachine::getNameWithPrefix(SmallVectorImpl<char> &Name,
     Mang.getNameWithPrefix(Name, GV, false);
     return;
   }
-  SectionKind GVKind = TargetLoweringObjectFile::getKindForGlobal(GV, *this);
   const TargetLoweringObjectFile *TLOF = getObjFileLowering();
-  const MCSection *TheSection = TLOF->SectionForGlobal(GV, GVKind, Mang, *this);
-  bool CannotUsePrivateLabel = !canUsePrivateLabel(*AsmInfo, *TheSection);
-  TLOF->getNameWithPrefix(Name, GV, CannotUsePrivateLabel, Mang, *this);
+  TLOF->getNameWithPrefix(Name, GV, Mang, *this);
 }
 
 MCSymbol *TargetMachine::getSymbol(const GlobalValue *GV, Mangler &Mang) const {