; LLVM IR from JessonYue/LeetCodeLearning :: Array/caiweixiong/c (homework_str_test)

; 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
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 ptr, align 8
  %7 = alloca ptr, align 8
  %8 = alloca ptr, align 8
  %9 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  %10 = load ptr, ptr %4, align 8, !tbaa !5
  %11 = icmp ne ptr %10, null
  br i1 %11, label %12, label %15

12:                                               ; preds = %2
  %13 = load ptr, ptr %5, align 8, !tbaa !5
  %14 = icmp ne ptr %13, null
  br i1 %14, label %16, label %15

15:                                               ; preds = %12, %2
  store ptr null, ptr %3, align 8
  br label %59

16:                                               ; preds = %12
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %17 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %17, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #2
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %18, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #2
  %19 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %19, ptr %8, align 8, !tbaa !5
  br label %20

20:                                               ; preds = %56, %16
  %21 = load ptr, ptr %6, align 8, !tbaa !5
  %22 = load i8, ptr %21, align 1, !tbaa !9
  %23 = sext i8 %22 to i32
  %24 = icmp ne i32 %23, 0
  br i1 %24, label %25, label %57

25:                                               ; preds = %20
  %26 = load ptr, ptr %8, align 8, !tbaa !5
  %27 = load i8, ptr %26, align 1, !tbaa !9
  %28 = sext i8 %27 to i32
  %29 = icmp eq i32 %28, 0
  br i1 %29, label %30, label %32

30:                                               ; preds = %25
  %31 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %31, ptr %3, align 8
  store i32 1, ptr %9, align 4
  br label %58

32:                                               ; preds = %25
  %33 = load ptr, ptr %7, align 8, !tbaa !5
  %34 = load i8, ptr %33, align 1, !tbaa !9
  %35 = sext i8 %34 to i32
  %36 = icmp eq i32 %35, 0
  br i1 %36, label %37, label %38

37:                                               ; preds = %32
  store ptr null, ptr %3, align 8
  store i32 1, ptr %9, align 4
  br label %58

38:                                               ; preds = %32
  %39 = load ptr, ptr %7, align 8, !tbaa !5
  %40 = load i8, ptr %39, align 1, !tbaa !9
  %41 = sext i8 %40 to i32
  %42 = load ptr, ptr %8, align 8, !tbaa !5
  %43 = load i8, ptr %42, align 1, !tbaa !9
  %44 = sext i8 %43 to i32
  %45 = icmp eq i32 %41, %44
  br i1 %45, label %46, label %51

46:                                               ; preds = %38
  %47 = load ptr, ptr %7, align 8, !tbaa !5
  %48 = getelementptr inbounds i8, ptr %47, i32 1
  store ptr %48, ptr %7, align 8, !tbaa !5
  %49 = load ptr, ptr %8, align 8, !tbaa !5
  %50 = getelementptr inbounds i8, ptr %49, i32 1
  store ptr %50, ptr %8, align 8, !tbaa !5
  br label %56

51:                                               ; preds = %38
  %52 = load ptr, ptr %6, align 8, !tbaa !5
  %53 = getelementptr inbounds i8, ptr %52, i32 1
  store ptr %53, ptr %6, align 8, !tbaa !5
  %54 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %54, ptr %7, align 8, !tbaa !5
  %55 = load ptr, ptr %5, align 8, !tbaa !5
  store ptr %55, ptr %8, align 8, !tbaa !5
  br label %56

56:                                               ; preds = %51, %46
  br label %20, !llvm.loop !10

57:                                               ; preds = %20
  store ptr null, ptr %3, align 8
  store i32 1, ptr %9, align 4
  br label %58

58:                                               ; preds = %57, %37, %30
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #2
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  br label %59

59:                                               ; preds = %58, %15
  %60 = load ptr, ptr %3, align 8
  ret ptr %60
}

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 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"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(read, inaccessiblemem: none) uwtable
define dso_local noundef ptr @my_strstr(ptr noundef readonly %0, ptr noundef readonly %1) local_unnamed_addr #0 {
  %3 = icmp ne ptr %0, null
  %4 = icmp ne ptr %1, null
  %or.cond = and i1 %3, %4
  br i1 %or.cond, label %.preheader, label %.loopexit

.preheader:                                       ; preds = %2
  %5 = load i8, ptr %0, align 1, !tbaa !5
  %.not28 = icmp eq i8 %5, 0
  br i1 %.not28, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader, %11
  %.031 = phi ptr [ %.1, %11 ], [ %1, %.preheader ]
  %.01830 = phi ptr [ %.119, %11 ], [ %0, %.preheader ]
  %.02029 = phi ptr [ %.121, %11 ], [ %0, %.preheader ]
  %6 = load i8, ptr %.031, align 1, !tbaa !5
  %7 = icmp eq i8 %6, 0
  br i1 %7, label %.loopexit, label %8

8:                                                ; preds = %.lr.ph
  %9 = load i8, ptr %.01830, align 1, !tbaa !5
  %10 = icmp eq i8 %9, 0
  br i1 %10, label %.loopexit, label %11

11:                                               ; preds = %8
  %12 = icmp eq i8 %9, %6
  %13 = getelementptr inbounds i8, ptr %.01830, i64 1
  %14 = getelementptr inbounds i8, ptr %.031, i64 1
  %15 = getelementptr inbounds i8, ptr %.02029, i64 1
  %.121 = select i1 %12, ptr %.02029, ptr %15
  %.119 = select i1 %12, ptr %13, ptr %15
  %.1 = select i1 %12, ptr %14, ptr %1
  %16 = load i8, ptr %.121, align 1, !tbaa !5
  %.not = icmp eq i8 %16, 0
  br i1 %.not, label %.loopexit, label %.lr.ph, !llvm.loop !8

.loopexit:                                        ; preds = %11, %8, %.lr.ph, %.preheader, %2
  %.123 = phi ptr [ null, %2 ], [ null, %.preheader ], [ null, %11 ], [ null, %8 ], [ %1, %.lr.ph ]
  ret ptr %.123
}

attributes #0 = { nofree norecurse nosync nounwind memory(read, inaccessiblemem: none) 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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C/C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


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