; LLVM IR from Hunterdii/GeeksforGeeks-POTD :: November 2024 GFG SOLUTION (November-24)

; 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 i64 @maxSubarraySum(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i64, align 8
  %6 = alloca i64, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store i32 %1, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %5) #2
  store i64 0, ptr %5, align 8, !tbaa !11
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  store i64 -9223372036854775808, ptr %6, align 8, !tbaa !11
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %56, %2
  %9 = load i32, ptr %7, align 4, !tbaa !9
  %10 = load i32, ptr %4, align 4, !tbaa !9
  %11 = icmp slt i32 %9, %10
  br i1 %11, label %13, label %12

12:                                               ; preds = %8
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  br label %59

13:                                               ; preds = %8
  %14 = load i64, ptr %5, align 8, !tbaa !11
  %15 = load ptr, ptr %3, align 8, !tbaa !5
  %16 = load i32, ptr %7, align 4, !tbaa !9
  %17 = sext i32 %16 to i64
  %18 = getelementptr inbounds i32, ptr %15, i64 %17
  %19 = load i32, ptr %18, align 4, !tbaa !9
  %20 = sext i32 %19 to i64
  %21 = add nsw i64 %14, %20
  %22 = load ptr, ptr %3, align 8, !tbaa !5
  %23 = load i32, ptr %7, align 4, !tbaa !9
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds i32, ptr %22, i64 %24
  %26 = load i32, ptr %25, align 4, !tbaa !9
  %27 = sext i32 %26 to i64
  %28 = icmp sgt i64 %21, %27
  br i1 %28, label %29, label %38

29:                                               ; preds = %13
  %30 = load i64, ptr %5, align 8, !tbaa !11
  %31 = load ptr, ptr %3, align 8, !tbaa !5
  %32 = load i32, ptr %7, align 4, !tbaa !9
  %33 = sext i32 %32 to i64
  %34 = getelementptr inbounds i32, ptr %31, i64 %33
  %35 = load i32, ptr %34, align 4, !tbaa !9
  %36 = sext i32 %35 to i64
  %37 = add nsw i64 %30, %36
  br label %45

38:                                               ; preds = %13
  %39 = load ptr, ptr %3, align 8, !tbaa !5
  %40 = load i32, ptr %7, align 4, !tbaa !9
  %41 = sext i32 %40 to i64
  %42 = getelementptr inbounds i32, ptr %39, i64 %41
  %43 = load i32, ptr %42, align 4, !tbaa !9
  %44 = sext i32 %43 to i64
  br label %45

45:                                               ; preds = %38, %29
  %46 = phi i64 [ %37, %29 ], [ %44, %38 ]
  store i64 %46, ptr %5, align 8, !tbaa !11
  %47 = load i64, ptr %6, align 8, !tbaa !11
  %48 = load i64, ptr %5, align 8, !tbaa !11
  %49 = icmp sgt i64 %47, %48
  br i1 %49, label %50, label %52

50:                                               ; preds = %45
  %51 = load i64, ptr %6, align 8, !tbaa !11
  br label %54

52:                                               ; preds = %45
  %53 = load i64, ptr %5, align 8, !tbaa !11
  br label %54

54:                                               ; preds = %52, %50
  %55 = phi i64 [ %51, %50 ], [ %53, %52 ]
  store i64 %55, ptr %6, align 8, !tbaa !11
  br label %56

56:                                               ; preds = %54
  %57 = load i32, ptr %7, align 4, !tbaa !9
  %58 = add nsw i32 %57, 1
  store i32 %58, ptr %7, align 4, !tbaa !9
  br label %8, !llvm.loop !13

59:                                               ; preds = %12
  %60 = load i64, ptr %6, align 8, !tbaa !11
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %5) #2
  ret i64 %60
}

; 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 = !{!12, !12, i64 0}
!12 = !{!"long long", !7, i64 0}
!13 = distinct !{!13, !14}
!14 = !{!"llvm.loop.mustprogress"}


; 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 i64 @maxSubarraySum(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
  %xtraiter = and i64 %wide.trip.count, 1
  %4 = icmp eq i32 %1, 1
  br i1 %4, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i64 %wide.trip.count, 2147483646
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.lcssa.ph = phi i64 [ poison, %.lr.ph.preheader ], [ %22, %.lr.ph ]
  %indvars.iv.unr = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01722.unr = phi i64 [ -9223372036854775808, %.lr.ph.preheader ], [ %22, %.lr.ph ]
  %.01821.unr = phi i64 [ 0, %.lr.ph.preheader ], [ %21, %.lr.ph ]
  %lcmp.mod.not = icmp eq i64 %xtraiter, 0
  br i1 %lcmp.mod.not, label %._crit_edge, label %.lr.ph.epil

.lr.ph.epil:                                      ; preds = %._crit_edge.loopexit.unr-lcssa
  %5 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv.unr
  %6 = load i32, ptr %5, align 4, !tbaa !5
  %7 = sext i32 %6 to i64
  %8 = tail call i64 @llvm.smax.i64(i64 %.01821.unr, i64 0)
  %9 = add nsw i64 %8, %7
  %10 = tail call i64 @llvm.smax.i64(i64 %.01722.unr, i64 %9)
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %2
  %.017.lcssa = phi i64 [ -9223372036854775808, %2 ], [ %.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %10, %.lr.ph.epil ]
  ret i64 %.017.lcssa

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader.new ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01722 = phi i64 [ -9223372036854775808, %.lr.ph.preheader.new ], [ %22, %.lr.ph ]
  %.01821 = phi i64 [ 0, %.lr.ph.preheader.new ], [ %21, %.lr.ph ]
  %niter = phi i64 [ 0, %.lr.ph.preheader.new ], [ %niter.next.1, %.lr.ph ]
  %11 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %12 = load i32, ptr %11, align 4, !tbaa !5
  %13 = sext i32 %12 to i64
  %14 = tail call i64 @llvm.smax.i64(i64 %.01821, i64 0)
  %15 = add nsw i64 %14, %13
  %16 = tail call i64 @llvm.smax.i64(i64 %.01722, i64 %15)
  %indvars.iv.next = or disjoint i64 %indvars.iv, 1
  %17 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv.next
  %18 = load i32, ptr %17, align 4, !tbaa !5
  %19 = sext i32 %18 to i64
  %20 = tail call i64 @llvm.smax.i64(i64 %15, i64 0)
  %21 = add nsw i64 %20, %19
  %22 = tail call i64 @llvm.smax.i64(i64 %16, i64 %21)
  %indvars.iv.next.1 = add nuw nsw i64 %indvars.iv, 2
  %niter.next.1 = add i64 %niter, 2
  %niter.ncmp.1 = icmp eq i64 %niter.next.1, %unroll_iter
  br i1 %niter.ncmp.1, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph, !llvm.loop !9
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i64 @llvm.smax.i64(i64, i64) #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}
!10 = !{!"llvm.loop.mustprogress"}


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