; 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: nounwind uwtable
define dso_local ptr @my_strchr(ptr noundef %0, i32 noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  br label %6

6:                                                ; preds = %21, %2
  %7 = load ptr, ptr %4, align 8, !tbaa !5
  %8 = load i8, ptr %7, align 1, !tbaa !11
  %9 = sext i8 %8 to i32
  %10 = load i32, ptr %5, align 4, !tbaa !9
  %11 = trunc i32 %10 to i8
  %12 = sext i8 %11 to i32
  %13 = icmp ne i32 %9, %12
  br i1 %13, label %14, label %24

14:                                               ; preds = %6
  %15 = load ptr, ptr %4, align 8, !tbaa !5
  %16 = load i8, ptr %15, align 1, !tbaa !11
  %17 = sext i8 %16 to i32
  %18 = icmp eq i32 %17, 0
  br i1 %18, label %19, label %20

19:                                               ; preds = %14
  store ptr null, ptr %3, align 8
  br label %26

20:                                               ; preds = %14
  br label %21

21:                                               ; preds = %20
  %22 = load ptr, ptr %4, align 8, !tbaa !5
  %23 = getelementptr inbounds i8, ptr %22, i32 1
  store ptr %23, ptr %4, align 8, !tbaa !5
  br label %6, !llvm.loop !12

24:                                               ; preds = %6
  %25 = load ptr, ptr %4, align 8, !tbaa !5
  store ptr %25, ptr %3, align 8
  br label %26

26:                                               ; preds = %24, %19
  %27 = load ptr, ptr %3, align 8
  ret ptr %27
}

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 = !{!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 {
  %sext = shl i32 %1, 24
  %3 = ashr exact i32 %sext, 24
  %4 = load i8, ptr %0, align 1, !tbaa !5
  %5 = sext i8 %4 to i32
  %.not7 = icmp eq i32 %3, %5
  br i1 %.not7, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %2, %8
  %6 = phi i8 [ %10, %8 ], [ %4, %2 ]
  %.058 = phi ptr [ %9, %8 ], [ %0, %2 ]
  %7 = icmp eq i8 %6, 0
  br i1 %7, label %._crit_edge, label %8

8:                                                ; preds = %.lr.ph
  %9 = getelementptr inbounds i8, ptr %.058, i64 1
  %10 = load i8, ptr %9, align 1, !tbaa !5
  %11 = sext i8 %10 to i32
  %.not = icmp eq i32 %3, %11
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !8

._crit_edge:                                      ; preds = %.lr.ph, %8, %2
  %.0 = phi ptr [ %0, %2 ], [ %9, %8 ], [ null, %.lr.ph ]
  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,InstCombinePass,JumpThreadingPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass