; LLVM IR from JessonYue/LeetCodeLearning :: Array/zhuqiguang/c/Strstr.ll (Z6strStrPcS_)

; 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: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z6strStrPcS_(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca i32, align 4
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = icmp eq ptr null, %11
  br i1 %12, label %16, label %13

13:                                               ; preds = %2
  %14 = load ptr, ptr %5, align 8, !tbaa !5
  %15 = icmp eq ptr null, %14
  br i1 %15, label %16, label %17

16:                                               ; preds = %13, %2
  store i32 0, ptr %3, align 4
  br label %52

17:                                               ; preds = %13
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  %19 = call i64 @strlen(ptr noundef %18) #4
  %20 = trunc i64 %19 to i32
  store i32 %20, ptr %7, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %8) #3
  %21 = load ptr, ptr %5, align 8, !tbaa !5
  %22 = call i64 @strlen(ptr noundef %21) #4
  %23 = trunc i64 %22 to i32
  store i32 %23, ptr %8, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #3
  store i32 0, ptr %9, align 4, !tbaa !9
  br label %24

24:                                               ; preds = %45, %17
  %25 = load i32, ptr %9, align 4, !tbaa !9
  %26 = load i32, ptr %7, align 4, !tbaa !9
  %27 = load i32, ptr %8, align 4, !tbaa !9
  %28 = sub nsw i32 %26, %27
  %29 = add nsw i32 %28, 1
  %30 = icmp slt i32 %25, %29
  br i1 %30, label %32, label %31

31:                                               ; preds = %24
  store i32 2, ptr %10, align 4
  br label %48

32:                                               ; preds = %24
  %33 = load ptr, ptr %4, align 8, !tbaa !5
  %34 = load i32, ptr %9, align 4, !tbaa !9
  %35 = sext i32 %34 to i64
  %36 = getelementptr inbounds i8, ptr %33, i64 %35
  %37 = load ptr, ptr %5, align 8, !tbaa !5
  %38 = load i32, ptr %8, align 4, !tbaa !9
  %39 = sext i32 %38 to i64
  %40 = call i32 @memcmp(ptr noundef %36, ptr noundef %37, i64 noundef %39) #4
  %41 = icmp eq i32 %40, 0
  br i1 %41, label %42, label %44

42:                                               ; preds = %32
  %43 = load i32, ptr %9, align 4, !tbaa !9
  store i32 %43, ptr %3, align 4
  store i32 1, ptr %10, align 4
  br label %48

44:                                               ; preds = %32
  br label %45

45:                                               ; preds = %44
  %46 = load i32, ptr %9, align 4, !tbaa !9
  %47 = add nsw i32 %46, 1
  store i32 %47, ptr %9, align 4, !tbaa !9
  br label %24, !llvm.loop !11

48:                                               ; preds = %42, %31
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #3
  %49 = load i32, ptr %10, align 4
  switch i32 %49, label %51 [
    i32 2, label %50
  ]

50:                                               ; preds = %48
  store i32 -1, ptr %3, align 4
  store i32 1, ptr %10, align 4
  br label %51

51:                                               ; preds = %50, %48
  call void @llvm.lifetime.end.p0(i64 4, ptr %8) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  br label %52

52:                                               ; preds = %51, %16
  %53 = load i32, ptr %3, align 4
  ret i32 %53
}

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #1

; Function Attrs: nounwind willreturn memory(read)
declare i64 @strlen(ptr noundef) #2

; Function Attrs: nounwind willreturn memory(read)
declare i32 @memcmp(ptr noundef, ptr noundef, i64 noundef) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #1

attributes #0 = { mustprogress 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 #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nounwind willreturn memory(read) "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 willreturn memory(read) }

!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++ TBAA"}
!9 = !{!10, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = distinct !{!11, !12}
!12 = !{!"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: mustprogress nofree nounwind willreturn memory(argmem: read) uwtable
define dso_local noundef i32 @_Z6strStrPcS_(ptr noundef readonly %0, ptr noundef readonly %1) local_unnamed_addr #0 {
  %3 = icmp eq ptr %0, null
  %4 = icmp eq ptr %1, null
  %or.cond = or i1 %3, %4
  br i1 %or.cond, label %.loopexit, label %5

5:                                                ; preds = %2
  %6 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %0) #3
  %7 = trunc i64 %6 to i32
  %8 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) #3
  %9 = trunc i64 %8 to i32
  %.not19 = icmp slt i32 %7, %9
  br i1 %.not19, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %5
  %sext = shl i64 %8, 32
  %10 = ashr exact i64 %sext, 32
  %11 = add i64 %6, 1
  %12 = sub i64 %11, %8
  %wide.trip.count = and i64 %12, 4294967295
  br label %13

13:                                               ; preds = %.lr.ph, %16
  %indvars.iv = phi i64 [ 0, %.lr.ph ], [ %indvars.iv.next, %16 ]
  %14 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv
  %bcmp = tail call i32 @bcmp(ptr %14, ptr %1, i64 %10)
  %15 = icmp eq i32 %bcmp, 0
  br i1 %15, label %.loopexit.loopexit.split.loop.exit24, label %16

16:                                               ; preds = %13
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %.loopexit, label %13, !llvm.loop !5

.loopexit.loopexit.split.loop.exit24:             ; preds = %13
  %17 = trunc nuw nsw i64 %indvars.iv to i32
  br label %.loopexit

.loopexit:                                        ; preds = %16, %.loopexit.loopexit.split.loop.exit24, %5, %2
  %.2 = phi i32 [ 0, %2 ], [ -1, %5 ], [ %17, %.loopexit.loopexit.split.loop.exit24 ], [ -1, %16 ]
  ret i32 %.2
}

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: read)
declare i64 @strlen(ptr nocapture noundef) local_unnamed_addr #1

; Function Attrs: nofree nounwind willreturn memory(argmem: read)
declare i32 @bcmp(ptr nocapture, ptr nocapture, i64) local_unnamed_addr #2

attributes #0 = { mustprogress nofree nounwind willreturn memory(argmem: read) 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 #1 = { mustprogress nofree nounwind willreturn memory(argmem: read) "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 = { nofree nounwind willreturn memory(argmem: read) }
attributes #3 = { nounwind willreturn memory(read) }

!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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LICMPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass