; LLVM IR from JessonYue/LeetCodeLearning :: Array/zhangjunwei/7.13-7.18 (str)

; 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: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nounwind uwtable
declare dso_local i64 @my_strlen(ptr noundef) #1

; Function Attrs: nounwind uwtable
declare dso_local i32 @my_memcmp(ptr noundef, ptr noundef, i64 noundef) #1

; Function Attrs: nounwind uwtable
define dso_local ptr @my_strstr(ptr noundef %0, ptr noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i64, align 8
  %7 = alloca i32, align 4
  %8 = alloca i64, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %9 = load ptr, ptr %5, align 8, !tbaa !5
  %10 = call i64 @my_strlen(ptr noundef %9)
  store i64 %10, ptr %6, align 8, !tbaa !9
  %11 = load i64, ptr %6, align 8, !tbaa !9
  %12 = icmp ne i64 %11, 0
  br i1 %12, label %15, label %13

13:                                               ; preds = %2
  %14 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %14, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %37

15:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #2
  %16 = load ptr, ptr %4, align 8, !tbaa !5
  %17 = call i64 @my_strlen(ptr noundef %16)
  store i64 %17, ptr %8, align 8, !tbaa !9
  br label %18

18:                                               ; preds = %32, %15
  %19 = load i64, ptr %8, align 8, !tbaa !9
  %20 = load i64, ptr %6, align 8, !tbaa !9
  %21 = icmp uge i64 %19, %20
  br i1 %21, label %22, label %35

22:                                               ; preds = %18
  %23 = load i64, ptr %8, align 8, !tbaa !9
  %24 = add i64 %23, -1
  store i64 %24, ptr %8, align 8, !tbaa !9
  %25 = load ptr, ptr %4, align 8, !tbaa !5
  %26 = load ptr, ptr %5, align 8, !tbaa !5
  %27 = load i64, ptr %6, align 8, !tbaa !9
  %28 = call i32 @my_memcmp(ptr noundef %25, ptr noundef %26, i64 noundef %27)
  %29 = icmp ne i32 %28, 0
  br i1 %29, label %32, label %30

30:                                               ; preds = %22
  %31 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %31, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %36

32:                                               ; preds = %22
  %33 = load ptr, ptr %4, align 8, !tbaa !5
  %34 = getelementptr inbounds i8, ptr %33, i32 1
  store ptr %34, ptr %4, align 8, !tbaa !5
  br label %18, !llvm.loop !11

35:                                               ; preds = %18
  store ptr null, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %36

36:                                               ; preds = %35, %30
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #2
  br label %37

37:                                               ; preds = %36, %13
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  %38 = load ptr, ptr %3, align 8
  ret ptr %38
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { 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 #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 = !{!"long", !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: nounwind uwtable
declare dso_local i64 @my_strlen(ptr noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
declare dso_local i32 @my_memcmp(ptr noundef, ptr noundef, i64 noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local noundef ptr @my_strstr(ptr noundef %0, ptr noundef %1) local_unnamed_addr #0 {
  %3 = tail call i64 @my_strlen(ptr noundef %1)
  %.not = icmp eq i64 %3, 0
  br i1 %.not, label %.loopexit, label %4

4:                                                ; preds = %2
  %5 = tail call i64 @my_strlen(ptr noundef %0)
  %.not1517 = icmp ult i64 %5, %3
  br i1 %.not1517, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %4, %7
  %.019 = phi i64 [ %8, %7 ], [ %5, %4 ]
  %.01318 = phi ptr [ %9, %7 ], [ %0, %4 ]
  %6 = tail call i32 @my_memcmp(ptr noundef %.01318, ptr noundef %1, i64 noundef %3)
  %.not16 = icmp eq i32 %6, 0
  br i1 %.not16, label %.loopexit, label %7

7:                                                ; preds = %.lr.ph
  %8 = add i64 %.019, -1
  %9 = getelementptr inbounds i8, ptr %.01318, i64 1
  %.not15 = icmp ult i64 %8, %3
  br i1 %.not15, label %.loopexit, label %.lr.ph, !llvm.loop !5

.loopexit:                                        ; preds = %7, %.lr.ph, %4, %2
  %.1 = phi ptr [ %0, %2 ], [ null, %4 ], [ null, %7 ], [ %.01318, %.lr.ph ]
  ret ptr %.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" }

!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"}


; Effective O3 passes: GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass