; LLVM IR from JessonYue/LeetCodeLearning :: Array/wuchao/other/7-16 c实现string函数 (StringUtils)

; 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: nounwind allocsize(0)
declare noalias ptr @malloc(i64 noundef) #1

; Function Attrs: nounwind uwtable
declare dso_local i64 @stringLen(ptr noundef) #2

; 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 @strcat(ptr noundef %0, ptr noundef %1) #2 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca ptr, align 8
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  store ptr %0, ptr %3, align 8, !tbaa !5
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  %10 = load ptr, ptr %3, align 8, !tbaa !5
  %11 = call i64 @stringLen(ptr noundef %10)
  %12 = trunc i64 %11 to i32
  store i32 %12, ptr %5, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  %13 = load ptr, ptr %4, align 8, !tbaa !5
  %14 = call i64 @stringLen(ptr noundef %13)
  %15 = trunc i64 %14 to i32
  store i32 %15, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %7) #3
  %16 = load i32, ptr %5, align 4, !tbaa !9
  %17 = load i32, ptr %6, align 4, !tbaa !9
  %18 = add nsw i32 %16, %17
  %19 = sext i32 %18 to i64
  %20 = mul i64 %19, 1
  %21 = call noalias ptr @malloc(i64 noundef %20) #4
  store ptr %21, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #3
  store i32 0, ptr %8, align 4, !tbaa !9
  br label %22

22:                                               ; preds = %26, %2
  %23 = load i32, ptr %8, align 4, !tbaa !9
  %24 = load i32, ptr %5, align 4, !tbaa !9
  %25 = icmp slt i32 %23, %24
  br i1 %25, label %26, label %38

26:                                               ; preds = %22
  %27 = load ptr, ptr %3, align 8, !tbaa !5
  %28 = load i32, ptr %8, align 4, !tbaa !9
  %29 = sext i32 %28 to i64
  %30 = getelementptr inbounds i8, ptr %27, i64 %29
  %31 = load i8, ptr %30, align 1, !tbaa !11
  %32 = load ptr, ptr %7, align 8, !tbaa !5
  %33 = load i32, ptr %8, align 4, !tbaa !9
  %34 = sext i32 %33 to i64
  %35 = getelementptr inbounds i8, ptr %32, i64 %34
  store i8 %31, ptr %35, align 1, !tbaa !11
  %36 = load i32, ptr %8, align 4, !tbaa !9
  %37 = add nsw i32 %36, 1
  store i32 %37, ptr %8, align 4, !tbaa !9
  br label %22, !llvm.loop !12

38:                                               ; preds = %22
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #3
  store i32 0, ptr %9, align 4, !tbaa !9
  br label %39

39:                                               ; preds = %43, %38
  %40 = load i32, ptr %9, align 4, !tbaa !9
  %41 = load i32, ptr %6, align 4, !tbaa !9
  %42 = icmp slt i32 %40, %41
  br i1 %42, label %43, label %57

43:                                               ; preds = %39
  %44 = load ptr, ptr %4, align 8, !tbaa !5
  %45 = load i32, ptr %9, align 4, !tbaa !9
  %46 = sext i32 %45 to i64
  %47 = getelementptr inbounds i8, ptr %44, i64 %46
  %48 = load i8, ptr %47, align 1, !tbaa !11
  %49 = load ptr, ptr %7, align 8, !tbaa !5
  %50 = load i32, ptr %8, align 4, !tbaa !9
  %51 = sext i32 %50 to i64
  %52 = getelementptr inbounds i8, ptr %49, i64 %51
  store i8 %48, ptr %52, align 1, !tbaa !11
  %53 = load i32, ptr %8, align 4, !tbaa !9
  %54 = add nsw i32 %53, 1
  store i32 %54, ptr %8, align 4, !tbaa !9
  %55 = load i32, ptr %9, align 4, !tbaa !9
  %56 = add nsw i32 %55, 1
  store i32 %56, ptr %9, align 4, !tbaa !9
  br label %39, !llvm.loop !14

57:                                               ; preds = %39
  %58 = load ptr, ptr %7, align 8, !tbaa !5
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #3
  call void @llvm.lifetime.end.p0(i64 8, ptr %7) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  ret ptr %58
}

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { nounwind allocsize(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 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 #3 = { nounwind }
attributes #4 = { nounwind allocsize(0) }

!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"}
!14 = distinct !{!14, !13}


; 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: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
declare noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
declare dso_local i64 @stringLen(ptr noundef) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
define dso_local noalias noundef ptr @strcat(ptr noundef %0, ptr noundef %1) local_unnamed_addr #1 {
  %3 = tail call i64 @stringLen(ptr noundef %0)
  %4 = trunc i64 %3 to i32
  %5 = tail call i64 @stringLen(ptr noundef %1)
  %6 = trunc i64 %5 to i32
  %7 = add i64 %5, %3
  %sext = shl i64 %7, 32
  %8 = ashr exact i64 %sext, 32
  %9 = tail call noalias ptr @malloc(i64 noundef %8) #3
  %10 = icmp sgt i32 %4, 0
  br i1 %10, label %.lr.ph.preheader, label %.preheader

.lr.ph.preheader:                                 ; preds = %2
  %11 = and i64 %3, 2147483647
  tail call void @llvm.memcpy.p0.p0.i64(ptr align 1 %9, ptr align 1 %0, i64 %11, i1 false), !tbaa !5
  %12 = and i64 %3, 2147483647
  br label %.preheader

.preheader:                                       ; preds = %.lr.ph.preheader, %2
  %.019.lcssa = phi i64 [ 0, %2 ], [ %12, %.lr.ph.preheader ]
  %13 = icmp sgt i32 %6, 0
  br i1 %13, label %.lr.ph23.preheader, label %._crit_edge

.lr.ph23.preheader:                               ; preds = %.preheader
  %scevgep = getelementptr i8, ptr %9, i64 %.019.lcssa
  %14 = and i64 %5, 2147483647
  tail call void @llvm.memcpy.p0.p0.i64(ptr align 1 %scevgep, ptr align 1 %1, i64 %14, i1 false), !tbaa !5
  br label %._crit_edge

._crit_edge:                                      ; preds = %.lr.ph23.preheader, %.preheader
  ret ptr %9
}

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: readwrite)
declare void @llvm.memcpy.p0.p0.i64(ptr noalias nocapture writeonly, ptr noalias nocapture readonly, i64, i1 immarg) #2

attributes #0 = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" "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 #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 = { nocallback nofree nounwind willreturn memory(argmem: readwrite) }
attributes #3 = { nounwind allocsize(0) }

!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"}


; Effective O3 passes: EarlyCSEPass,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,LCSSAPass,LoopIdiomRecognizePass,LoopRotatePass,LoopSimplifyPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass