; LLVM IR from JessonYue/LeetCodeLearning :: Array/zhuqiguang/c (StringU)

; 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_strchr(ptr noundef %0, i32 noundef %1) #1 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  br label %8

8:                                                ; preds = %23, %2
  %9 = load ptr, ptr %4, align 8, !tbaa !5
  %10 = load i8, ptr %9, align 1, !tbaa !11
  %11 = icmp ne i8 %10, 0
  br i1 %11, label %12, label %26

12:                                               ; preds = %8
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %13, ptr %6, align 8, !tbaa !5
  br label %14

14:                                               ; preds = %12
  %15 = load ptr, ptr %6, align 8, !tbaa !5
  %16 = getelementptr inbounds i8, ptr %15, i32 1
  store ptr %16, ptr %6, align 8, !tbaa !5
  %17 = load i8, ptr %16, align 1, !tbaa !11
  %18 = sext i8 %17 to i32
  %19 = load i32, ptr %5, align 4, !tbaa !9
  %20 = icmp eq i32 %18, %19
  br i1 %20, label %21, label %23

21:                                               ; preds = %14
  %22 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %22, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %27

23:                                               ; preds = %14
  %24 = load ptr, ptr %4, align 8, !tbaa !5
  %25 = getelementptr inbounds i8, ptr %24, i32 1
  store ptr %25, ptr %4, align 8, !tbaa !5
  br label %8, !llvm.loop !12

26:                                               ; preds = %8
  store ptr null, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %27

27:                                               ; preds = %26, %21
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  %28 = load ptr, ptr %3, align 8
  ret ptr %28
}

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 = !{!"int", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"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_strchr(ptr noundef readonly %0, i32 noundef %1) local_unnamed_addr #0 {
  %.pr = load i8, ptr %0, align 1, !tbaa !5
  br label %3

3:                                                ; preds = %5, %2
  %4 = phi i8 [ %7, %5 ], [ %.pr, %2 ]
  %.06 = phi ptr [ %6, %5 ], [ %0, %2 ]
  %.not = icmp eq i8 %4, 0
  br i1 %.not, label %10, label %5

5:                                                ; preds = %3
  %6 = getelementptr inbounds i8, ptr %.06, i64 1
  %7 = load i8, ptr %6, align 1, !tbaa !5
  %8 = sext i8 %7 to i32
  %9 = icmp eq i32 %8, %1
  br i1 %9, label %10, label %3, !llvm.loop !8

10:                                               ; preds = %3, %5
  %.0 = phi ptr [ %6, %5 ], [ null, %3 ]
  ret ptr %.0
}

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,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass