From 3c47c5ca13b8a502de3272e8105548715947b7a8 Mon Sep 17 00:00:00 2001
From: Ilya Yanok <ilya.yanok@gmail.com>
Date: Tue, 9 Nov 2021 21:35:43 +0100
Subject: [PATCH] [RegAllocFast] Fix nondeterminism in debuginfo generation

Changes from commit 1db137b1859692ae33228c530d4df9f2431b2151
added iteration over hash map that can result in non-deterministic
order. Fix that by using a SmallMapVector to preserve the order.

Differential Revision: https://reviews.llvm.org/D113468
---
 llvm/lib/CodeGen/RegAllocFast.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/llvm/lib/CodeGen/RegAllocFast.cpp b/llvm/lib/CodeGen/RegAllocFast.cpp
index 707161d5a8b073..68920e2e50df48 100644
--- a/llvm/lib/CodeGen/RegAllocFast.cpp
+++ b/llvm/lib/CodeGen/RegAllocFast.cpp
@@ -15,6 +15,7 @@
 #include "llvm/ADT/ArrayRef.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/IndexedMap.h"
+#include "llvm/ADT/MapVector.h"
 #include "llvm/ADT/SmallSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/SparseSet.h"
@@ -432,7 +433,7 @@ void RegAllocFast::spill(MachineBasicBlock::iterator Before, Register VirtReg,
   // every definition of it, meaning we can switch all the DBG_VALUEs over
   // to just reference the stack slot.
   SmallVectorImpl<MachineOperand *> &LRIDbgOperands = LiveDbgValueMap[VirtReg];
-  SmallDenseMap<MachineInstr *, SmallVector<const MachineOperand *>>
+  SmallMapVector<MachineInstr *, SmallVector<const MachineOperand *>, 2>
       SpilledOperandsMap;
   for (MachineOperand *MO : LRIDbgOperands)
     SpilledOperandsMap[MO->getParent()].push_back(MO);