; LLVM IR from JessonYue/LeetCodeLearning :: Array/huyang/0713 (mycstring)

; 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 void @strcat(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  br label %5

5:                                                ; preds = %10, %2
  %6 = load ptr, ptr %3, align 8, !tbaa !5
  %7 = load i8, ptr %6, align 1, !tbaa !9
  %8 = sext i8 %7 to i32
  %9 = icmp ne i32 %8, 0
  br i1 %9, label %10, label %13

10:                                               ; preds = %5
  %11 = load ptr, ptr %3, align 8, !tbaa !5
  %12 = getelementptr inbounds i8, ptr %11, i32 1
  store ptr %12, ptr %3, align 8, !tbaa !5
  br label %5, !llvm.loop !10

13:                                               ; preds = %5
  br label %14

14:                                               ; preds = %19, %13
  %15 = load ptr, ptr %4, align 8, !tbaa !5
  %16 = load i8, ptr %15, align 1, !tbaa !9
  %17 = sext i8 %16 to i32
  %18 = icmp ne i32 %17, 0
  br i1 %18, label %19, label %27

19:                                               ; preds = %14
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  %21 = load i8, ptr %20, align 1, !tbaa !9
  %22 = load ptr, ptr %3, align 8, !tbaa !5
  store i8 %21, ptr %22, align 1, !tbaa !9
  %23 = load ptr, ptr %3, align 8, !tbaa !5
  %24 = getelementptr inbounds i8, ptr %23, i32 1
  store ptr %24, ptr %3, align 8, !tbaa !5
  %25 = load ptr, ptr %4, align 8, !tbaa !5
  %26 = getelementptr inbounds i8, ptr %25, i32 1
  store ptr %26, ptr %4, align 8, !tbaa !5
  br label %14, !llvm.loop !12

27:                                               ; preds = %14
  store ptr null, ptr %3, align 8, !tbaa !5
  ret void
}

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 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}
!12 = distinct !{!12, !11}


; 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(readwrite, inaccessiblemem: none) uwtable
define dso_local void @strcat(ptr nocapture noundef %0, ptr nocapture noundef readonly %1) local_unnamed_addr #0 {
  br label %3

3:                                                ; preds = %3, %2
  %.07 = phi ptr [ %0, %2 ], [ %5, %3 ]
  %4 = load i8, ptr %.07, align 1, !tbaa !5
  %.not = icmp eq i8 %4, 0
  %5 = getelementptr inbounds i8, ptr %.07, i64 1
  br i1 %.not, label %.preheader, label %3, !llvm.loop !8

.preheader:                                       ; preds = %3
  %6 = load i8, ptr %1, align 1, !tbaa !5
  %.not89 = icmp eq i8 %6, 0
  br i1 %.not89, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %.preheader, %.lr.ph
  %7 = phi i8 [ %10, %.lr.ph ], [ %6, %.preheader ]
  %.011 = phi ptr [ %9, %.lr.ph ], [ %1, %.preheader ]
  %.110 = phi ptr [ %8, %.lr.ph ], [ %.07, %.preheader ]
  store i8 %7, ptr %.110, align 1, !tbaa !5
  %8 = getelementptr inbounds i8, ptr %.110, i64 1
  %9 = getelementptr inbounds i8, ptr %.011, i64 1
  %10 = load i8, ptr %9, align 1, !tbaa !5
  %.not8 = icmp eq i8 %10, 0
  br i1 %.not8, label %._crit_edge, label %.lr.ph, !llvm.loop !10

._crit_edge:                                      ; preds = %.lr.ph, %.preheader
  ret void
}

attributes #0 = { nofree norecurse nosync nounwind memory(readwrite, 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"}
!10 = distinct !{!10, !9}


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