Tweak some atomics functions in preparation for larger changes; NFC.

- Rename getATOMIC to getSYNC, as llvm will soon be able to emit both
  '__sync' libcalls and '__atomic' libcalls, and this function is for
  the '__sync' ones.

- getInsertFencesForAtomic() has been replaced with
  shouldInsertFencesForAtomic(Instruction), so that the decision can be
  made per-instruction. This functionality will be used soon.

- emitLeadingFence/emitTrailingFence are no longer called if
  shouldInsertFencesForAtomic returns false, and thus don't need to
  check the condition themselves.

llvm-svn: 263665

2 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 7eab758180f..9d1eee0b9f5 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -916,7 +916,6 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM,
     break;
   }
 
-  setInsertFencesForAtomic(true);
 
   if (Subtarget.enableMachineScheduler())
     setSchedulingPreference(Sched::Source);
diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.h b/llvm/lib/Target/PowerPC/PPCISelLowering.h
index 44bcb8942cf..c83c86f16ed 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.h
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.h
@@ -508,6 +508,10 @@ namespace llvm {
 
     unsigned getPrefLoopAlignment(MachineLoop *ML) const override;
 
+    bool shouldInsertFencesForAtomic(const Instruction *I) const override {
+      return true;
+    }
+
     Instruction* emitLeadingFence(IRBuilder<> &Builder, AtomicOrdering Ord,
                                   bool IsStore, bool IsLoad) const override;
     Instruction* emitTrailingFence(IRBuilder<> &Builder, AtomicOrdering Ord,