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, 7 insertions, 4 deletions

diff --git a/llvm/lib/Target/Sparc/SparcISelLowering.cpp b/llvm/lib/Target/Sparc/SparcISelLowering.cpp
index 37613126d6f..d08d30aa82f 100644
--- a/llvm/lib/Target/Sparc/SparcISelLowering.cpp
+++ b/llvm/lib/Target/Sparc/SparcISelLowering.cpp
@@ -1603,10 +1603,6 @@ SparcTargetLowering::SparcTargetLowering(TargetMachine &TM,
   }
 
   // ATOMICs.
-  // FIXME: We insert fences for each atomics and generate sub-optimal code
-  // for PSO/TSO. Also, implement other atomicrmw operations.
-
-  setInsertFencesForAtomic(true);
 
   setOperationAction(ISD::ATOMIC_SWAP, MVT::i32, Legal);
   setOperationAction(ISD::ATOMIC_CMP_SWAP, MVT::i32,
diff --git a/llvm/lib/Target/Sparc/SparcISelLowering.h b/llvm/lib/Target/Sparc/SparcISelLowering.h
index 4e46709cfc0..c470fa8d661 100644
--- a/llvm/lib/Target/Sparc/SparcISelLowering.h
+++ b/llvm/lib/Target/Sparc/SparcISelLowering.h
@@ -180,6 +180,13 @@ namespace llvm {
       return VT != MVT::f128;
     }
 
+    bool shouldInsertFencesForAtomic(const Instruction *I) const override {
+      // FIXME: We insert fences for each atomics and generate
+      // sub-optimal code for PSO/TSO. (Approximately nobody uses any
+      // mode but TSO, which makes this even more silly)
+      return true;
+    }
+
     void ReplaceNodeResults(SDNode *N,
                             SmallVectorImpl<SDValue>& Results,
                             SelectionDAG &DAG) const override;