; LLVM IR from AlgoGenesis/C :: Dynamic Programming/Maximum Subarray Problem (Kadane’s Algorithm) (Program)

; 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 @maxSubArray(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) #2
  %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) #2
  %11 = load ptr, ptr %3, align 8, !tbaa !5
  %12 = getelementptr inbounds i32, ptr %11, i64 0
  %13 = load i32, ptr %12, align 4, !tbaa !9
  store i32 %13, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  store i32 1, ptr %7, align 4, !tbaa !9
  br label %14

14:                                               ; preds = %55, %2
  %15 = load i32, ptr %7, align 4, !tbaa !9
  %16 = load i32, ptr %4, align 4, !tbaa !9
  %17 = icmp slt i32 %15, %16
  br i1 %17, label %19, label %18

18:                                               ; preds = %14
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  br label %58

19:                                               ; preds = %14
  %20 = load ptr, ptr %3, align 8, !tbaa !5
  %21 = load i32, ptr %7, align 4, !tbaa !9
  %22 = sext i32 %21 to i64
  %23 = getelementptr inbounds i32, ptr %20, i64 %22
  %24 = load i32, ptr %23, align 4, !tbaa !9
  %25 = load i32, ptr %5, align 4, !tbaa !9
  %26 = load ptr, ptr %3, align 8, !tbaa !5
  %27 = load i32, ptr %7, align 4, !tbaa !9
  %28 = sext i32 %27 to i64
  %29 = getelementptr inbounds i32, ptr %26, i64 %28
  %30 = load i32, ptr %29, align 4, !tbaa !9
  %31 = add nsw i32 %25, %30
  %32 = icmp sgt i32 %24, %31
  br i1 %32, label %33, label %39

33:                                               ; preds = %19
  %34 = load ptr, ptr %3, align 8, !tbaa !5
  %35 = load i32, ptr %7, align 4, !tbaa !9
  %36 = sext i32 %35 to i64
  %37 = getelementptr inbounds i32, ptr %34, i64 %36
  %38 = load i32, ptr %37, align 4, !tbaa !9
  br label %47

39:                                               ; preds = %19
  %40 = load i32, ptr %5, align 4, !tbaa !9
  %41 = load ptr, ptr %3, align 8, !tbaa !5
  %42 = load i32, ptr %7, 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 = add nsw i32 %40, %45
  br label %47

47:                                               ; preds = %39, %33
  %48 = phi i32 [ %38, %33 ], [ %46, %39 ]
  store i32 %48, ptr %5, align 4, !tbaa !9
  %49 = load i32, ptr %5, align 4, !tbaa !9
  %50 = load i32, ptr %6, align 4, !tbaa !9
  %51 = icmp sgt i32 %49, %50
  br i1 %51, label %52, label %54

52:                                               ; preds = %47
  %53 = load i32, ptr %5, align 4, !tbaa !9
  store i32 %53, ptr %6, align 4, !tbaa !9
  br label %54

54:                                               ; preds = %52, %47
  br label %55

55:                                               ; preds = %54
  %56 = load i32, ptr %7, align 4, !tbaa !9
  %57 = add nsw i32 %56, 1
  store i32 %57, ptr %7, align 4, !tbaa !9
  br label %14, !llvm.loop !11

58:                                               ; preds = %18
  %59 = load i32, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  ret i32 %59
}

; 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"}


; 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 @maxSubArray(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, 1
  br i1 %4, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %wide.trip.count = zext nneg i32 %1 to i64
  %5 = add nsw i64 %wide.trip.count, -1
  %xtraiter = and i64 %5, 1
  %6 = icmp eq i32 %1, 2
  br i1 %6, label %._crit_edge.loopexit.unr-lcssa, label %.lr.ph.preheader.new

.lr.ph.preheader.new:                             ; preds = %.lr.ph.preheader
  %unroll_iter = and i64 %5, -2
  %invariant.gep = getelementptr inbounds i8, ptr %0, i64 4
  br label %.lr.ph

._crit_edge.loopexit.unr-lcssa:                   ; preds = %.lr.ph, %.lr.ph.preheader
  %.1.lcssa.ph = phi i32 [ poison, %.lr.ph.preheader ], [ %.1.1, %.lr.ph ]
  %indvars.iv.unr = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01824.unr = phi i32 [ %3, %.lr.ph.preheader ], [ %.1.1, %.lr.ph ]
  %.01923.unr = phi i32 [ %3, %.lr.ph.preheader ], [ %17, %.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
  %7 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv.unr
  %8 = load i32, ptr %7, align 4, !tbaa !5
  %9 = tail call i32 @llvm.smax.i32(i32 %.01923.unr, i32 0)
  %10 = add nsw i32 %8, %9
  %.1.epil = tail call i32 @llvm.smax.i32(i32 %10, i32 %.01824.unr)
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph.epil, %._crit_edge.loopexit.unr-lcssa, %2
  %.018.lcssa = phi i32 [ %3, %2 ], [ %.1.lcssa.ph, %._crit_edge.loopexit.unr-lcssa ], [ %.1.epil, %.lr.ph.epil ]
  ret i32 %.018.lcssa

.lr.ph:                                           ; preds = %.lr.ph, %.lr.ph.preheader.new
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader.new ], [ %indvars.iv.next.1, %.lr.ph ]
  %.01824 = phi i32 [ %3, %.lr.ph.preheader.new ], [ %.1.1, %.lr.ph ]
  %.01923 = phi i32 [ %3, %.lr.ph.preheader.new ], [ %17, %.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 = tail call i32 @llvm.smax.i32(i32 %.01923, i32 0)
  %14 = add nsw i32 %12, %13
  %.1 = tail call i32 @llvm.smax.i32(i32 %14, i32 %.01824)
  %gep = getelementptr inbounds i32, ptr %invariant.gep, i64 %indvars.iv
  %15 = load i32, ptr %gep, align 4, !tbaa !5
  %16 = tail call i32 @llvm.smax.i32(i32 %14, i32 0)
  %17 = add nsw i32 %15, %16
  %.1.1 = tail call i32 @llvm.smax.i32(i32 %17, i32 %.1)
  %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 i32 @llvm.smax.i32(i32, 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}
!10 = !{!"llvm.loop.mustprogress"}


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