; LLVM IR from Lakhankumawat/LearnCPP :: S-SortingAlgorithms/ShellSort.ll (Z9shellSortPii)

; 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: mustprogress nounwind uwtable
define dso_local void @_Z9shellSortPii(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
  %8 = 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
  %9 = load i32, ptr %4, align 4, !tbaa !9
  %10 = sdiv i32 %9, 2
  store i32 %10, ptr %5, align 4, !tbaa !9
  br label %11

11:                                               ; preds = %69, %2
  %12 = load i32, ptr %5, align 4, !tbaa !9
  %13 = icmp sge i32 %12, 1
  br i1 %13, label %14, label %72

14:                                               ; preds = %11
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #2
  %15 = load i32, ptr %5, align 4, !tbaa !9
  store i32 %15, ptr %6, align 4, !tbaa !9
  br label %16

16:                                               ; preds = %66, %14
  %17 = load i32, ptr %6, align 4, !tbaa !9
  %18 = load i32, ptr %4, align 4, !tbaa !9
  %19 = icmp slt i32 %17, %18
  br i1 %19, label %21, label %20

20:                                               ; preds = %16
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #2
  br label %69

21:                                               ; preds = %16
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #2
  %22 = load ptr, ptr %3, align 8, !tbaa !5
  %23 = load i32, ptr %6, 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
  store i32 %26, ptr %7, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  %27 = load i32, ptr %6, align 4, !tbaa !9
  store i32 %27, ptr %8, align 4, !tbaa !9
  br label %28

28:                                               ; preds = %56, %21
  %29 = load i32, ptr %8, align 4, !tbaa !9
  %30 = load i32, ptr %5, align 4, !tbaa !9
  %31 = icmp sge i32 %29, %30
  br i1 %31, label %32, label %42

32:                                               ; preds = %28
  %33 = load ptr, ptr %3, align 8, !tbaa !5
  %34 = load i32, ptr %8, align 4, !tbaa !9
  %35 = load i32, ptr %5, align 4, !tbaa !9
  %36 = sub nsw i32 %34, %35
  %37 = sext i32 %36 to i64
  %38 = getelementptr inbounds i32, ptr %33, i64 %37
  %39 = load i32, ptr %38, align 4, !tbaa !9
  %40 = load i32, ptr %7, align 4, !tbaa !9
  %41 = icmp sgt i32 %39, %40
  br label %42

42:                                               ; preds = %32, %28
  %43 = phi i1 [ false, %28 ], [ %41, %32 ]
  br i1 %43, label %44, label %60

44:                                               ; preds = %42
  %45 = load ptr, ptr %3, align 8, !tbaa !5
  %46 = load i32, ptr %8, align 4, !tbaa !9
  %47 = load i32, ptr %5, align 4, !tbaa !9
  %48 = sub nsw i32 %46, %47
  %49 = sext i32 %48 to i64
  %50 = getelementptr inbounds i32, ptr %45, i64 %49
  %51 = load i32, ptr %50, align 4, !tbaa !9
  %52 = load ptr, ptr %3, align 8, !tbaa !5
  %53 = load i32, ptr %8, align 4, !tbaa !9
  %54 = sext i32 %53 to i64
  %55 = getelementptr inbounds i32, ptr %52, i64 %54
  store i32 %51, ptr %55, align 4, !tbaa !9
  br label %56

56:                                               ; preds = %44
  %57 = load i32, ptr %5, align 4, !tbaa !9
  %58 = load i32, ptr %8, align 4, !tbaa !9
  %59 = sub nsw i32 %58, %57
  store i32 %59, ptr %8, align 4, !tbaa !9
  br label %28, !llvm.loop !11

60:                                               ; preds = %42
  %61 = load i32, ptr %7, align 4, !tbaa !9
  %62 = load ptr, ptr %3, align 8, !tbaa !5
  %63 = load i32, ptr %8, align 4, !tbaa !9
  %64 = sext i32 %63 to i64
  %65 = getelementptr inbounds i32, ptr %62, i64 %64
  store i32 %61, ptr %65, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #2
  br label %66

66:                                               ; preds = %60
  %67 = load i32, ptr %6, align 4, !tbaa !9
  %68 = add nsw i32 %67, 1
  store i32 %68, ptr %6, align 4, !tbaa !9
  br label %16, !llvm.loop !13

69:                                               ; preds = %20
  %70 = load i32, ptr %5, align 4, !tbaa !9
  %71 = sdiv i32 %70, 2
  store i32 %71, ptr %5, align 4, !tbaa !9
  br label %11, !llvm.loop !14

72:                                               ; preds = %11
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  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

attributes #0 = { mustprogress 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++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = distinct !{!13, !12}
!14 = distinct !{!14, !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: mustprogress nofree norecurse nosync nounwind memory(argmem: readwrite) uwtable
define dso_local void @_Z9shellSortPii(ptr nocapture noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %3 = icmp sgt i32 %1, 1
  br i1 %3, label %.preheader, label %._crit_edge35

.preheader:                                       ; preds = %2, %._crit_edge
  %.02534.in = phi i32 [ %.02534, %._crit_edge ], [ %1, %2 ]
  %.02534 = lshr i32 %.02534.in, 1
  %4 = icmp slt i32 %.02534, %1
  br i1 %4, label %.lr.ph33.preheader, label %._crit_edge

.lr.ph33.preheader:                               ; preds = %.preheader
  %5 = zext nneg i32 %.02534 to i64
  br label %.lr.ph33

._crit_edge:                                      ; preds = %.critedge, %.preheader
  %.not36 = icmp ult i32 %.02534.in, 4
  br i1 %.not36, label %._crit_edge35, label %.preheader, !llvm.loop !5

.lr.ph33:                                         ; preds = %.lr.ph33.preheader, %.critedge
  %indvars.iv = phi i64 [ %5, %.lr.ph33.preheader ], [ %indvars.iv.next, %.critedge ]
  %6 = getelementptr inbounds i32, ptr %0, i64 %indvars.iv
  %7 = load i32, ptr %6, align 4, !tbaa !7
  %8 = trunc nuw i64 %indvars.iv to i32
  %.not28 = icmp sgt i32 %.02534, %8
  br i1 %.not28, label %.critedge, label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph33, %14
  %.029 = phi i32 [ %9, %14 ], [ %8, %.lr.ph33 ]
  %9 = sub nsw i32 %.029, %.02534
  %10 = sext i32 %9 to i64
  %11 = getelementptr inbounds i32, ptr %0, i64 %10
  %12 = load i32, ptr %11, align 4, !tbaa !7
  %13 = icmp sgt i32 %12, %7
  br i1 %13, label %14, label %.critedge

14:                                               ; preds = %.lr.ph
  %15 = zext nneg i32 %.029 to i64
  %16 = getelementptr inbounds i32, ptr %0, i64 %15
  store i32 %12, ptr %16, align 4, !tbaa !7
  %.not = icmp slt i32 %9, %.02534
  br i1 %.not, label %.critedge, label %.lr.ph, !llvm.loop !11

.critedge:                                        ; preds = %.lr.ph, %14, %.lr.ph33
  %.0.lcssa = phi i32 [ %8, %.lr.ph33 ], [ %9, %14 ], [ %.029, %.lr.ph ]
  %17 = sext i32 %.0.lcssa to i64
  %18 = getelementptr inbounds i32, ptr %0, i64 %17
  store i32 %7, ptr %18, align 4, !tbaa !7
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %19 = trunc nuw i64 %indvars.iv.next to i32
  %20 = icmp slt i32 %19, %1
  br i1 %20, label %.lr.ph33, label %._crit_edge, !llvm.loop !12

._crit_edge35:                                    ; preds = %._crit_edge, %2
  ret void
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind memory(argmem: readwrite) 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" }

!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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}
!7 = !{!8, !8, i64 0}
!8 = !{!"int", !9, i64 0}
!9 = !{!"omnipotent char", !10, i64 0}
!10 = !{!"Simple C++ TBAA"}
!11 = distinct !{!11, !6}
!12 = distinct !{!12, !6}


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