Fix differences in codegen between Linux and Windows toolchains

Summary:
    There are differences in codegen between Linux and Windows due to:
    1. Using std::sort which uses quicksort which is a non-stable sort.

    2. Iterating over Set data structure where the iteration order is
       non deterministic.

Reviewers: arsenm, grosbach, junbuml, zinob, MatzeB

Subscribers: MatzeB, wdng

Differential Revision: https://reviews.llvm.org/D25695

llvm-svn: 284441

1 files changed, 2 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp
index f431ee9ba00..a43277cb8dc 100644
--- a/llvm/lib/CodeGen/MachineScheduler.cpp
+++ b/llvm/lib/CodeGen/MachineScheduler.cpp
@@ -1359,7 +1359,8 @@ class BaseMemOpClusterMutation : public ScheduleDAGMutation {
         : SU(su), BaseReg(reg), Offset(ofs) {}
 
     bool operator<(const MemOpInfo&RHS) const {
-      return std::tie(BaseReg, Offset) < std::tie(RHS.BaseReg, RHS.Offset);
+      return std::tie(BaseReg, Offset, SU->NodeNum) <
+             std::tie(RHS.BaseReg, RHS.Offset, RHS.SU->NodeNum);
     }
   };