Index: llvm/lib/Transforms/Scalar/LoopDataPrefetch.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopDataPrefetch.cpp
+++ llvm/lib/Transforms/Scalar/LoopDataPrefetch.cpp
@@ -29,6 +29,7 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Transforms/Scalar.h"
 #include "llvm/Transforms/Utils.h"
+#include "llvm/Transforms/Utils/LoopSimplify.h"
 #include "llvm/Transforms/Utils/ScalarEvolutionExpander.h"
 
 #define DEBUG_TYPE "loop-data-prefetch"
@@ -179,8 +180,17 @@
       &AM.getResult<OptimizationRemarkEmitterAnalysis>(F);
   const TargetTransformInfo *TTI = &AM.getResult<TargetIRAnalysis>(F);
 
+  // Ensure loops are in simplifed form which is a pre-requisite for loop data
+  // prefetch pass. Added only for new PM since the legacy PM has already added
+  // LoopSimplify pass as a dependency.
+  bool Changed = false;
+  for (auto &L : *LI) {
+    Changed |=
+        simplifyLoop(L, DT, LI, SE, AC, nullptr, false /* PreserveLCSSA */);
+  }
+
   LoopDataPrefetch LDP(AC, DT, LI, SE, TTI, ORE);
-  bool Changed = LDP.run();
+  Changed |= LDP.run();
 
   if (Changed) {
     PreservedAnalyses PA;
Index: llvm/test/Transforms/LoopDataPrefetch/AArch64/pr43784.ll
===================================================================
--- llvm/test/Transforms/LoopDataPrefetch/AArch64/pr43784.ll
+++ llvm/test/Transforms/LoopDataPrefetch/AArch64/pr43784.ll
@@ -1,4 +1,4 @@
-; RUN: opt -mcpu=kryo -passes=loop-simplify,loop-data-prefetch -max-prefetch-iters-ahead=1000 -min-prefetch-stride=16 -S < %s | FileCheck %s
+; RUN: opt -mcpu=kryo -passes=loop-data-prefetch -max-prefetch-iters-ahead=1000 -min-prefetch-stride=16 -S < %s | FileCheck %s
 
 target datalayout = "e-m:e-i8:8:32-i16:16:32-i64:64-i128:128-n32:64-S128"
 target triple = "aarch64-unknown-linux-gnu"