; 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_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
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = icmp ne ptr %8, null
  br i1 %9, label %11, label %10

10:                                               ; preds = %2
  store ptr null, ptr %3, align 8
  br label %31

11:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 8, ptr %6) #2
  %12 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %12, ptr %6, align 8, !tbaa !5
  br label %13

13:                                               ; preds = %26, %11
  %14 = load ptr, ptr %6, align 8, !tbaa !5
  %15 = load i8, ptr %14, align 1, !tbaa !11
  %16 = sext i8 %15 to i32
  %17 = icmp ne i32 %16, 0
  br i1 %17, label %18, label %29

18:                                               ; preds = %13
  %19 = load ptr, ptr %6, align 8, !tbaa !5
  %20 = load i8, ptr %19, align 1, !tbaa !11
  %21 = sext i8 %20 to i32
  %22 = load i32, ptr %5, align 4, !tbaa !9
  %23 = icmp eq i32 %21, %22
  br i1 %23, label %24, label %26

24:                                               ; preds = %18
  %25 = load ptr, ptr %6, align 8, !tbaa !5
  store ptr %25, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %30

26:                                               ; preds = %18
  %27 = load ptr, ptr %6, align 8, !tbaa !5
  %28 = getelementptr inbounds i8, ptr %27, i32 1
  store ptr %28, ptr %6, align 8, !tbaa !5
  br label %13, !llvm.loop !12

29:                                               ; preds = %13
  store ptr null, ptr %3, align 8
  store i32 1, ptr %7, align 4
  br label %30

30:                                               ; preds = %29, %24
  call void @llvm.lifetime.end.p0(i64 8, ptr %6) #2
  br label %31

31:                                               ; preds = %30, %10
  %32 = load ptr, ptr %3, align 8
  ret ptr %32
}

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 {
  %.not = icmp eq ptr %0, null
  br i1 %.not, label %.loopexit, label %.preheader

.preheader:                                       ; preds = %2
  %3 = load i8, ptr %0, align 1, !tbaa !5
  %.not1011 = icmp eq i8 %3, 0
  br i1 %.not1011, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader, %7
  %4 = phi i8 [ %9, %7 ], [ %3, %.preheader ]
  %.012 = phi ptr [ %8, %7 ], [ %0, %.preheader ]
  %5 = sext i8 %4 to i32
  %6 = icmp eq i32 %5, %1
  br i1 %6, label %.loopexit, label %7

7:                                                ; preds = %.lr.ph
  %8 = getelementptr inbounds i8, ptr %.012, i64 1
  %9 = load i8, ptr %8, align 1, !tbaa !5
  %.not10 = icmp eq i8 %9, 0
  br i1 %.not10, label %.loopexit, label %.lr.ph, !llvm.loop !8

.loopexit:                                        ; preds = %7, %.lr.ph, %.preheader, %2
  %.1 = phi ptr [ null, %2 ], [ null, %.preheader ], [ null, %7 ], [ %.012, %.lr.ph ]
  ret ptr %.1
}

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