Use std::atomic<std::uint64_t> instead of std::atomic_uint64_t

[tmsriram]

Summary

Using std::atomic_uint64_t leads to "error: no type named 'atomic_uint64_t' in namespace 'std'"

[Amir]

LGTM but I'm curious which compiler produces this error

[MaskRay]

The issue may just be that <atomic> is not included. But not using these atomic aliases appears to be more common.

[tmsriram]

clang -v of the failing command:
clang -cc1 version 11.0.0 based upon LLVM 11.0.0git default target
x86_64-unknown-linux-gnu

[MaskRay]

I added #include <atomic> to bolt/include/bolt/Passes/ShrinkWrapping.h which may have fixed the issue.

bolt/include/bolt/Passes/ShrinkWrapping.h

class ShrinkWrapping {
   std::vector<int64_t> PushOffsetByReg;
   std::vector<int64_t> PopOffsetByReg;
   std::vector<MCPhysReg> DomOrder;
   CalleeSavedAnalysis CSA;
   std::vector<std::vector<uint64_t>> BestSaveCount;
   std::vector<std::vector<MCInst *>> BestSavePos;
 
   /// Pass stats
-  static std::atomic_uint64_t SpillsMovedRegularMode;
-  static std::atomic_uint64_t SpillsMovedPushPopMode;
-  static std::atomic_uint64_t SpillsMovedDynamicCount;
-  static std::atomic_uint64_t SpillsFailedDynamicCount;
-  static std::atomic_uint64_t InstrDynamicCount;
-  static std::atomic_uint64_t StoreDynamicCount;
+  static std::atomic<std::uint64_t> SpillsMovedRegularMode;
+  static std::atomic<std::uint64_t> SpillsMovedPushPopMode;
+  static std::atomic<std::uint64_t> SpillsMovedDynamicCount;
+  static std::atomic<std::uint64_t> SpillsFailedDynamicCount;
+  static std::atomic<std::uint64_t> InstrDynamicCount;
+  static std::atomic<std::uint64_t> StoreDynamicCount;
 
   Optional<unsigned> AnnotationIndex;
 
   /// Allow our custom worklist-sensitive analysis
   /// PredictiveStackPointerTracking to access WorklistItem
 public:
   struct WorklistItem {
     enum ActionType : uint8_t {

bolt/lib/Passes/ShrinkWrapping.cpp

 }
 
 void StackLayoutModifier::initialize() {
   classifyStackAccesses();
   classifyCFIs();
   IsInitialized = true;
 }
 
-std::atomic_uint64_t ShrinkWrapping::SpillsMovedRegularMode{0};
-std::atomic_uint64_t ShrinkWrapping::SpillsMovedPushPopMode{0};
-std::atomic_uint64_t ShrinkWrapping::SpillsMovedDynamicCount{0};
-std::atomic_uint64_t ShrinkWrapping::SpillsFailedDynamicCount{0};
-std::atomic_uint64_t ShrinkWrapping::InstrDynamicCount{0};
-std::atomic_uint64_t ShrinkWrapping::StoreDynamicCount{0};
+std::atomic<std::uint64_t> ShrinkWrapping::SpillsMovedRegularMode{0};
+std::atomic<std::uint64_t> ShrinkWrapping::SpillsMovedPushPopMode{0};
+std::atomic<std::uint64_t> ShrinkWrapping::SpillsMovedDynamicCount{0};
+std::atomic<std::uint64_t> ShrinkWrapping::SpillsFailedDynamicCount{0};
+std::atomic<std::uint64_t> ShrinkWrapping::InstrDynamicCount{0};
+std::atomic<std::uint64_t> ShrinkWrapping::StoreDynamicCount{0};
 
 using BBIterTy = BinaryBasicBlock::iterator;
 
 void ShrinkWrapping::classifyCSRUses() {
   DominatorAnalysis<false> &DA = Info.getDominatorAnalysis();
   StackPointerTracking &SPT = Info.getStackPointerTracking();
   UsesByReg = std::vector<BitVector>(BC.MRI->getNumRegs(),
                                      BitVector(DA.NumInstrs, false));