Subzero: Support non sequentially consistent memory orderings for atomic ops.

src/IceIntrinsics.h

 //===- subzero/src/IceIntrinsics.h - List of Ice Intrinsics -----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares the kinds of intrinsics supported by PNaCl.
@@ skipping 73 matching lines @@
     MemoryOrderInvalid = 0, // Invalid, keep first.
     MemoryOrderRelaxed,
     MemoryOrderConsume,
     MemoryOrderAcquire,
     MemoryOrderRelease,
     MemoryOrderAcquireRelease,
     MemoryOrderSequentiallyConsistent,
     MemoryOrderNum // Invalid, keep last.
   };
 
-  static bool VerifyMemoryOrder(uint64_t Order);
+  // Verify memory ordering rules for atomic intrinsics.  For
+  // AtomicCmpxchg, Order is the "success" ordering and OrderOther is
+  // the "failure" ordering.  Returns true if valid, false if invalid.
+  // TODO(stichnot,kschimpf): Perform memory order validation in the
+  // bitcode reader/parser, allowing LLVM and Subzero to share.  See
+  // https://code.google.com/p/nativeclient/issues/detail?id=4126 .
+  static bool isMemoryOrderValid(IntrinsicID ID, uint64_t Order,
+                                 uint64_t OrderOther = MemoryOrderInvalid);
 
   enum SideEffects { SideEffects_F = 0, SideEffects_T = 1 };
 
   enum ReturnsTwice { ReturnsTwice_F = 0, ReturnsTwice_T = 1 };
 
   // Basic attributes related to each intrinsic, that are relevant to
   // code generation. Perhaps the attributes representation can be shared
   // with general function calls, but PNaCl currently strips all
   // attributes from functions.
   struct IntrinsicInfo {
@@ skipping 51 matching lines @@
 
 private:
   // TODO(jvoung): May want to switch to something like LLVM's StringMap.
   typedef std::map<IceString, FullIntrinsicInfo> IntrinsicMap;
   IntrinsicMap Map;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEINTRINSICS_H