[llvm] [Hexagon] Fix -Wuninitialized warning (PR #125565)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-hexagon

Author: Brian Cain (androm3da)

<details>
<summary>Changes</summary>

`gcc (GCC) 14.2.1 20240910` reports the warning below on the baseline, this change fixes the warning.

    In file included from /home/user/CLionProjects/llvm-project/llvm/lib/Target/Hexagon/BitTracker.cpp:55:
    /home/user/CLionProjects/llvm-project/llvm/lib/Target/Hexagon/BitTracker.h: In constructor ‘llvm::BitTracker::UseQueueType::UseQueueType()’:
    /home/user/CLionProjects/llvm-project/llvm/lib/Target/Hexagon/BitTracker.h:75:27: warning: member ‘llvm::BitTracker::UseQueueType::Dist’ is used uninitialized [-Wuninitialized]
       75 |     UseQueueType() : Uses(Dist) {}
          |                           ^~~~

Fixes #<!-- -->125545

---
Full diff: https://github.com/llvm/llvm-project/pull/125565.diff


1 Files Affected:

- (modified) llvm/lib/Target/Hexagon/BitTracker.h (+2-2) 


``````````diff
diff --git a/llvm/lib/Target/Hexagon/BitTracker.h b/llvm/lib/Target/Hexagon/BitTracker.h
index 08c0359a4b7f06..a07abdb7303321 100644
--- a/llvm/lib/Target/Hexagon/BitTracker.h
+++ b/llvm/lib/Target/Hexagon/BitTracker.h
@@ -72,7 +72,7 @@ struct BitTracker {
   // Priority queue of instructions using modified registers, ordered by
   // their relative position in a basic block.
   struct UseQueueType {
-    UseQueueType() : Uses(Dist) {}
+    UseQueueType() : Dist(), Uses(Dist) {}
 
     unsigned size() const {
       return Uses.size();
@@ -100,9 +100,9 @@ struct BitTracker {
       bool operator()(const MachineInstr *MI, const MachineInstr *MJ) const;
       DenseMap<const MachineInstr*,unsigned> &Dist;
     };
-    std::priority_queue<MachineInstr*, std::vector<MachineInstr*>, Cmp> Uses;
     DenseSet<const MachineInstr*> Set; // Set to avoid adding duplicate entries.
     DenseMap<const MachineInstr*,unsigned> Dist;
+    std::priority_queue<MachineInstr *, std::vector<MachineInstr *>, Cmp> Uses;
   };
 
   void reset();

``````````

</details>


https://github.com/llvm/llvm-project/pull/125565