; LLVM IR from Hunterdii/GeeksforGeeks-POTD :: March 2024 GFG SOLUTION (March-01)

; Unoptimized IR (clang -disable-llvm-passes):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

; Function Attrs: nounwind uwtable
define dso_local i32 @peakElement(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  store i32 -2147483648, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %10

10:                                               ; preds = %30, %2
  %11 = load i32, ptr %7, align 4, !tbaa !9
  %12 = load i32, ptr %5, align 4, !tbaa !9
  %13 = icmp slt i32 %11, %12
  br i1 %13, label %15, label %14

14:                                               ; preds = %10
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  br label %33

15:                                               ; preds = %10
  %16 = load i32, ptr %6, align 4, !tbaa !9
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  %18 = load i32, ptr %7, align 4, !tbaa !9
  %19 = sext i32 %18 to i64
  %20 = getelementptr inbounds i32, ptr %17, i64 %19
  %21 = load i32, ptr %20, align 4, !tbaa !9
  %22 = icmp slt i32 %16, %21
  br i1 %22, label %23, label %29

23:                                               ; preds = %15
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = load i32, ptr %7, align 4, !tbaa !9
  %26 = sext i32 %25 to i64
  %27 = getelementptr inbounds i32, ptr %24, i64 %26
  %28 = load i32, ptr %27, align 4, !tbaa !9
  store i32 %28, ptr %6, align 4, !tbaa !9
  br label %29

29:                                               ; preds = %23, %15
  br label %30

30:                                               ; preds = %29
  %31 = load i32, ptr %7, align 4, !tbaa !9
  %32 = add nsw i32 %31, 1
  store i32 %32, ptr %7, align 4, !tbaa !9
  br label %10, !llvm.loop !11

33:                                               ; preds = %14
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  store i32 0, ptr %8, align 4, !tbaa !9
  br label %34

34:                                               ; preds = %50, %33
  %35 = load i32, ptr %8, align 4, !tbaa !9
  %36 = load i32, ptr %5, align 4, !tbaa !9
  %37 = icmp slt i32 %35, %36
  br i1 %37, label %39, label %38

38:                                               ; preds = %34
  store i32 5, ptr %9, align 4
  br label %53

39:                                               ; preds = %34
  %40 = load i32, ptr %6, align 4, !tbaa !9
  %41 = load ptr, ptr %4, align 8, !tbaa !5
  %42 = load i32, ptr %8, align 4, !tbaa !9
  %43 = sext i32 %42 to i64
  %44 = getelementptr inbounds i32, ptr %41, i64 %43
  %45 = load i32, ptr %44, align 4, !tbaa !9
  %46 = icmp eq i32 %40, %45
  br i1 %46, label %47, label %49

47:                                               ; preds = %39
  %48 = load i32, ptr %8, align 4, !tbaa !9
  store i32 %48, ptr %3, align 4
  store i32 1, ptr %9, align 4
  br label %53

49:                                               ; preds = %39
  br label %50

50:                                               ; preds = %49
  %51 = load i32, ptr %8, align 4, !tbaa !9
  %52 = add nsw i32 %51, 1
  store i32 %52, ptr %8, align 4, !tbaa !9
  br label %34, !llvm.loop !13

53:                                               ; preds = %47, %38
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  %54 = load i32, ptr %9, align 4
  switch i32 %54, label %56 [
    i32 5, label %55
  ]

55:                                               ; preds = %53
  store i32 -1, ptr %3, align 4
  store i32 1, ptr %9, align 4
  br label %56

56:                                               ; preds = %55, %53
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  %57 = load i32, ptr %3, align 4
  ret i32 %57
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { nounwind uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nounwind }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}


; Optimized IR (opt -passes='default<O3>'):
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

; Function Attrs: nofree norecurse nosync nounwind memory(argmem: read) uwtable
define dso_local i32 @peakElement(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp sgt i32 %1, 0
  br i1 %3, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %wide.trip.count = zext nneg i32 %1 to i64
  %min.iters.check = icmp ult i32 %1, 8
  br i1 %min.iters.check, label %.lr.ph.preheader45, label %vector.ph

.lr.ph.preheader45:                               ; preds = %middle.block, %.lr.ph.preheader
  %indvars.iv.ph = phi i64 [ 0, %.lr.ph.preheader ], [ %n.vec, %middle.block ]
  %.01824.ph = phi i32 [ -2147483648, %.lr.ph.preheader ], [ %9, %middle.block ]
  br label %.lr.ph

vector.ph:                                        ; preds = %.lr.ph.preheader
  %n.vec = and i64 %wide.trip.count, 2147483640
  br label %vector.body

vector.body:                                      ; preds = %vector.body, %vector.ph
  %index = phi i64 [ 0, %vector.ph ], [ %index.next, %vector.body ]
  %vec.phi = phi <4 x i32> [ <i32 -2147483648, i32 -2147483648, i32 -2147483648, i32 -2147483648>, %vector.ph ], [ %6, %vector.body ]
  %vec.phi42 = phi <4 x i32> [ <i32 -2147483648, i32 -2147483648, i32 -2147483648, i32 -2147483648>, %vector.ph ], [ %7, %vector.body ]
  %4 = getelementptr inbounds i32, ptr %0, i64 %index
  %5 = getelementptr inbounds i8, ptr %4, i64 16
  %wide.load = load <4 x i32>, ptr %4, align 4, !tbaa !5
  %wide.load43 = load <4 x i32>, ptr %5, align 4, !tbaa !5
  %6 = tail call <4 x i32> @llvm.smax.v4i32(<4 x i32> %vec.phi, <4 x i32> %wide.load)
  %7 = tail call <4 x i32> @llvm.smax.v4i32(<4 x i32> %vec.phi42, <4 x i32> %wide.load43)
  %index.next = add nuw i64 %index, 8
  %8 = icmp eq i64 %index.next, %n.vec
  br i1 %8, label %middle.block, label %vector.body, !llvm.loop !9

middle.block:                                     ; preds = %vector.body
  %rdx.minmax = tail call <4 x i32> @llvm.smax.v4i32(<4 x i32> %6, <4 x i32> %7)
  %9 = tail call i32 @llvm.vector.reduce.smax.v4i32(<4 x i32> %rdx.minmax)
  %cmp.n = icmp eq i64 %n.vec, %wide.trip.count
  br i1 %cmp.n, label %.preheader, label %.lr.ph.preheader45

.preheader:                                       ; preds = %.lr.ph, %middle.block
  %spec.select.lcssa = phi i32 [ %9, %middle.block ], [ %spec.select, %.lr.ph ]
  br i1 %3, label %.lr.ph28.preheader, label %._crit_edge

.lr.ph28.preheader:                               ; preds = %.preheader
  %wide.trip.count36 = zext nneg i32 %1 to i64
  br label %.lr.ph28

.lr.ph:                                           ; preds = %.lr.ph.preheader45, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ %indvars.iv.ph, %.lr.ph.preheader45 ]
  %.01824 = phi i32 [ %spec.select, %.lr.ph ], [ %.01824.ph, %.lr.ph.preheader45 ]
  %10 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %11 = load i32, ptr %10, align 4, !tbaa !5
  %spec.select = tail call i32 @llvm.smax.i32(i32 %.01824, i32 %11)
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %.preheader, label %.lr.ph, !llvm.loop !13

.lr.ph28:                                         ; preds = %.lr.ph28.preheader, %15
  %indvars.iv33 = phi i64 [ 0, %.lr.ph28.preheader ], [ %indvars.iv.next34, %15 ]
  %12 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv33
  %13 = load i32, ptr %12, align 4, !tbaa !5
  %14 = icmp eq i32 %spec.select.lcssa, %13
  br i1 %14, label %._crit_edge.loopexit.split.loop.exit, label %15

15:                                               ; preds = %.lr.ph28
  %indvars.iv.next34 = add nuw nsw i64 %indvars.iv33, 1
  %exitcond37.not = icmp eq i64 %indvars.iv.next34, %wide.trip.count36
  br i1 %exitcond37.not, label %._crit_edge, label %.lr.ph28, !llvm.loop !14

._crit_edge.loopexit.split.loop.exit:             ; preds = %.lr.ph28
  %16 = trunc nuw nsw i64 %indvars.iv33 to i32
  br label %._crit_edge

._crit_edge:                                      ; preds = %15, %._crit_edge.loopexit.split.loop.exit, %2, %.preheader
  %spec.select23 = phi i32 [ -1, %.preheader ], [ -1, %2 ], [ %16, %._crit_edge.loopexit.split.loop.exit ], [ -1, %15 ]
  ret i32 %spec.select23
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smax.i32(i32, i32) #1

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare <4 x i32> @llvm.smax.v4i32(<4 x i32>, <4 x i32>) #1

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.vector.reduce.smax.v4i32(<4 x i32>) #1

attributes #0 = { nofree norecurse nosync nounwind memory(argmem: read) uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }

!llvm.module.flags = !{!0, !1, !2, !3}
!llvm.ident = !{!4}

!0 = !{i32 1, !"wchar_size", i32 4}
!1 = !{i32 8, !"PIC Level", i32 2}
!2 = !{i32 7, !"PIE Level", i32 2}
!3 = !{i32 7, !"uwtable", i32 2}
!4 = !{!"clang version 19.1.0 (git@github.com:llvm/llvm-project.git a4bf6cd7cfb1a1421ba92bca9d017b49936c55e4)"}
!5 = !{!6, !6, i64 0}
!6 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = distinct !{!9, !10, !11, !12}
!10 = !{!"llvm.loop.mustprogress"}
!11 = !{!"llvm.loop.isvectorized", i32 1}
!12 = !{!"llvm.loop.unroll.runtime.disable"}
!13 = distinct !{!13, !10, !12, !11}
!14 = distinct !{!14, !10}


; Effective O3 passes: CorrelatedValuePropagationPass,EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopLoadEliminationPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,LoopVectorizePass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass