; LLVM IR from sbshah97/DS-Algo-Handbook :: Algorithms/Search_Algorithms/Binary_Search (BinarySearch_Iterative)

; 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 @binary_search(ptr noundef %0, i32 noundef %1, i32 noundef %2) #0 {
  %4 = alloca i32, align 4
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  %11 = alloca i32, align 4
  store ptr %0, ptr %5, align 8, !tbaa !5
  store i32 %1, ptr %6, align 4, !tbaa !9
  store i32 %2, ptr %7, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #2
  store i32 0, ptr %8, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #2
  %12 = load i32, ptr %6, align 4, !tbaa !9
  %13 = sub nsw i32 %12, 1
  store i32 %13, ptr %9, align 4, !tbaa !9
  br label %14

14:                                               ; preds = %50, %3
  %15 = load i32, ptr %8, align 4, !tbaa !9
  %16 = load i32, ptr %9, align 4, !tbaa !9
  %17 = icmp slt i32 %15, %16
  br i1 %17, label %18, label %51

18:                                               ; preds = %14
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #2
  %19 = load i32, ptr %8, align 4, !tbaa !9
  %20 = load i32, ptr %9, align 4, !tbaa !9
  %21 = add nsw i32 %19, %20
  %22 = sdiv i32 %21, 2
  store i32 %22, ptr %10, align 4, !tbaa !9
  %23 = load ptr, ptr %5, align 8, !tbaa !5
  %24 = load i32, ptr %10, align 4, !tbaa !9
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds i32, ptr %23, i64 %25
  %27 = load i32, ptr %26, align 4, !tbaa !9
  %28 = load i32, ptr %7, align 4, !tbaa !9
  %29 = icmp eq i32 %27, %28
  br i1 %29, label %30, label %32

30:                                               ; preds = %18
  %31 = load i32, ptr %10, align 4, !tbaa !9
  store i32 %31, ptr %4, align 4
  store i32 1, ptr %11, align 4
  br label %48

32:                                               ; preds = %18
  %33 = load ptr, ptr %5, align 8, !tbaa !5
  %34 = load i32, ptr %10, align 4, !tbaa !9
  %35 = sext i32 %34 to i64
  %36 = getelementptr inbounds i32, ptr %33, i64 %35
  %37 = load i32, ptr %36, align 4, !tbaa !9
  %38 = load i32, ptr %7, align 4, !tbaa !9
  %39 = icmp sgt i32 %37, %38
  br i1 %39, label %40, label %43

40:                                               ; preds = %32
  %41 = load i32, ptr %10, align 4, !tbaa !9
  %42 = sub nsw i32 %41, 1
  store i32 %42, ptr %9, align 4, !tbaa !9
  br label %46

43:                                               ; preds = %32
  %44 = load i32, ptr %10, align 4, !tbaa !9
  %45 = add nsw i32 %44, 1
  store i32 %45, ptr %8, align 4, !tbaa !9
  br label %46

46:                                               ; preds = %43, %40
  br label %47

47:                                               ; preds = %46
  store i32 0, ptr %11, align 4
  br label %48

48:                                               ; preds = %47, %30
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #2
  %49 = load i32, ptr %11, align 4
  switch i32 %49, label %52 [
    i32 0, label %50
  ]

50:                                               ; preds = %48
  br label %14, !llvm.loop !11

51:                                               ; preds = %14
  store i32 -1, ptr %4, align 4
  store i32 1, ptr %11, align 4
  br label %52

52:                                               ; preds = %51, %48
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #2
  %53 = load i32, ptr %4, align 4
  ret i32 %53
}

; 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 @binary_search(ptr nocapture noundef readonly %0, i32 noundef %1, i32 noundef %2) local_unnamed_addr #0 {
  %4 = icmp sgt i32 %1, 1
  br i1 %4, label %.lr.ph.preheader, label %.thread

.lr.ph.preheader:                                 ; preds = %3
  %5 = add nsw i32 %1, -1
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %11
  %.01628 = phi i32 [ %.117, %11 ], [ %5, %.lr.ph.preheader ]
  %.01927 = phi i32 [ %.120, %11 ], [ 0, %.lr.ph.preheader ]
  %6 = add nuw nsw i32 %.01628, %.01927
  %7 = lshr i32 %6, 1
  %8 = zext nneg i32 %7 to i64
  %9 = getelementptr inbounds i32, ptr %0, i64 %8
  %10 = load i32, ptr %9, align 4, !tbaa !5
  %.not = icmp eq i32 %10, %2
  br i1 %.not, label %.thread, label %11

11:                                               ; preds = %.lr.ph
  %12 = icmp sgt i32 %10, %2
  %13 = add nsw i32 %7, -1
  %14 = add nuw nsw i32 %7, 1
  %.120 = select i1 %12, i32 %.01927, i32 %14
  %.117 = select i1 %12, i32 %13, i32 %.01628
  %15 = icmp slt i32 %.120, %.117
  br i1 %15, label %.lr.ph, label %.thread

.thread:                                          ; preds = %11, %.lr.ph, %3
  %.2 = phi i32 [ -1, %3 ], [ %7, %.lr.ph ], [ -1, %11 ]
  ret i32 %.2
}

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" }

!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"}


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