; LLVM IR from Lakhankumawat/LearnCPP :: D-DynamicProgramming/Kadane's Algorithm/Kadane's Algorithm.ll (Z10largestSumPii)

; 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"

%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z10largestSumPii(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %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 4, ptr %5) #4
  %8 = load ptr, ptr %3, align 8, !tbaa !5
  %9 = getelementptr inbounds i32, ptr %8, i64 0
  %10 = load i32, ptr %9, align 4, !tbaa !9
  store i32 %10, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #4
  store i32 0, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %11

11:                                               ; preds = %34, %2
  %12 = load i32, ptr %7, align 4, !tbaa !9
  %13 = load i32, ptr %4, align 4, !tbaa !9
  %14 = icmp slt i32 %12, %13
  br i1 %14, label %16, label %15

15:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  br label %37

16:                                               ; preds = %11
  %17 = load i32, ptr %6, align 4, !tbaa !9
  %18 = load ptr, ptr %3, align 8, !tbaa !5
  %19 = load i32, ptr %7, align 4, !tbaa !9
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds i32, ptr %18, i64 %20
  %22 = load i32, ptr %21, align 4, !tbaa !9
  %23 = add nsw i32 %17, %22
  store i32 %23, ptr %6, align 4, !tbaa !9
  %24 = load i32, ptr %6, align 4, !tbaa !9
  %25 = load i32, ptr %5, align 4, !tbaa !9
  %26 = icmp sge i32 %24, %25
  br i1 %26, label %27, label %29

27:                                               ; preds = %16
  %28 = load i32, ptr %6, align 4, !tbaa !9
  store i32 %28, ptr %5, align 4, !tbaa !9
  br label %29

29:                                               ; preds = %27, %16
  %30 = load i32, ptr %6, align 4, !tbaa !9
  %31 = icmp slt i32 %30, 0
  br i1 %31, label %32, label %33

32:                                               ; preds = %29
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %33

33:                                               ; preds = %32, %29
  br label %34

34:                                               ; preds = %33
  %35 = load i32, ptr %7, align 4, !tbaa !9
  %36 = add nsw i32 %35, 1
  store i32 %36, ptr %7, align 4, !tbaa !9
  br label %11, !llvm.loop !11

37:                                               ; preds = %15
  %38 = load i32, ptr %5, align 4, !tbaa !9
  %39 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %38)
  %40 = call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %39, ptr noundef @.str)
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #4
  ret void
}

; 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

; Function Attrs: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) #2

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) #3

attributes #0 = { mustprogress 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 = { inlinehint mustprogress 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 #3 = { "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 #4 = { 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++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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"

%"class.std::basic_ostream" = type { ptr, %"class.std::basic_ios" }
%"class.std::basic_ios" = type { %"class.std::ios_base", ptr, i8, i8, ptr, ptr, ptr, ptr }
%"class.std::ios_base" = type { ptr, i64, i64, i32, i32, i32, ptr, %"struct.std::ios_base::_Words", [8 x %"struct.std::ios_base::_Words"], i32, ptr, %"class.std::locale" }
%"struct.std::ios_base::_Words" = type { ptr, i64 }
%"class.std::locale" = type { ptr }

@_ZSt4cout = external global %"class.std::basic_ostream", align 8
@.str = external hidden unnamed_addr constant [2 x i8], align 1

; Function Attrs: mustprogress uwtable
define dso_local void @_Z10largestSumPii(ptr nocapture noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = load i32, ptr %0, align 4, !tbaa !5
  %4 = icmp sgt i32 %1, 0
  br i1 %4, 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
  %5 = icmp eq i32 %1, 1
  br i1 %5, 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
  %spec.select.lcssa.ph = phi i32 [ poison, %.lr.ph.preheader ], [ %spec.select.1, %.lr.ph ]
  %indvars.iv.unr = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01115.unr = phi i32 [ 0, %.lr.ph.preheader ], [ %spec.store.select.1, %.lr.ph ]
  %.01214.unr = phi i32 [ %3, %.lr.ph.preheader ], [ %spec.select.1, %.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
  %6 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv.unr
  %7 = load i32, ptr %6, align 4, !tbaa !5
  %8 = add nsw i32 %7, %.01115.unr
  %spec.select.epil = tail call i32 @llvm.smax.i32(i32 %8, i32 %.01214.unr)
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %2
  %.012.lcssa = phi i32 [ %3, %2 ], [ %spec.select.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %spec.select.epil, %.lr.ph.epil ]
  %9 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8) @_ZSt4cout, i32 noundef %.012.lcssa)
  %10 = tail call noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8) %9, ptr noundef nonnull @.str)
  ret void

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader.new ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01115 = phi i32 [ 0, %.lr.ph.preheader.new ], [ %spec.store.select.1, %.lr.ph ]
  %.01214 = phi i32 [ %3, %.lr.ph.preheader.new ], [ %spec.select.1, %.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 = add nsw i32 %12, %.01115
  %spec.select = tail call i32 @llvm.smax.i32(i32 %13, i32 %.01214)
  %spec.store.select = tail call i32 @llvm.smax.i32(i32 %13, i32 0)
  %indvars.iv.next = or disjoint i64 %indvars.iv, 1
  %14 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv.next
  %15 = load i32, ptr %14, align 4, !tbaa !5
  %16 = add nsw i32 %15, %spec.store.select
  %spec.select.1 = tail call i32 @llvm.smax.i32(i32 %16, i32 %spec.select)
  %spec.store.select.1 = tail call i32 @llvm.smax.i32(i32 %16, i32 0)
  %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: inlinehint mustprogress uwtable
declare noundef nonnull align 8 dereferenceable(8) ptr @_ZStlsISt11char_traitsIcEERSt13basic_ostreamIcT_ES5_PKc(ptr noundef nonnull align 8 dereferenceable(8), ptr noundef) local_unnamed_addr #1

declare noundef nonnull align 8 dereferenceable(8) ptr @_ZNSolsEi(ptr noundef nonnull align 8 dereferenceable(8), i32 noundef) local_unnamed_addr #2

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.smax.i32(i32, i32) #3

attributes #0 = { mustprogress 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 = { inlinehint mustprogress 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 #2 = { "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 #3 = { 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++ 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