[PATCH] Implement emitLeading/TrailingFence in the ARM backend

[Renato Golin]

Hi Robin,

This patch seems to not do anything. Is this needed to something else? Are these functions going to be used somewhere else? If they are, why not implement it on the same patch? Otherwise, this just adds dead code.

It also makes is impossible for you to test this...

cheers,
--renato

================
Comment at: lib/Target/ARM/ARMISelLowering.cpp:11008
@@ +11007,3 @@
+
+// Based on http://ww.cl.cam.ac.uk/~pes20/cpp/cpp0xmappings.html
+void ARMTargetLowering::emitLeadingFence(IRBuilder<> &Builder,
----------------
www

================
Comment at: lib/Target/ARM/ARMISelLowering.cpp:11018
@@ +11017,3 @@
+    case Unordered:
+      llvm_unreachable("An unordered/not-atomic fence makes no sense");
+    case Monotonic:
----------------
"Invalid fence" seems less aggressive... :)

================
Comment at: lib/Target/ARM/ARMISelLowering.cpp:11046
@@ +11045,3 @@
+    case Unordered:
+      llvm_unreachable("An unordered/not-atomic fence makes no sense");
+    case Monotonic:
----------------
idem

================
Comment at: lib/Target/ARM/ARMISelLowering.h:422
@@ -416,4 +421,3 @@
 
     /// ARMPCLabelIndex - Keep track of the number of ARM PC labels created.
     unsigned ARMPCLabelIndex;
----------------
this could be left out

http://reviews.llvm.org/D4960