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

[Brian Cain via llvm-commits]

https://github.com/androm3da created https://github.com/llvm/llvm-project/pull/125565

`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

>From 9856d42f0d9aab6c3bd57c313c8059501bfcb357 Mon Sep 17 00:00:00 2001
From: Brian Cain <brian.cain at oss.qualcomm.com>
Date: Mon, 3 Feb 2025 11:51:53 -0800
Subject: [PATCH] [Hexagon] Fix -Wuninitialized warning
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

`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
---
 llvm/lib/Target/Hexagon/BitTracker.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

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();