; LLVM IR from lolosssss/leetcode :: c (58_length_of_last_word)

; 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 i32 @lengthOfLastWord(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #2
  store i32 0, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  store i32 0, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #2
  store i32 0, ptr %5, align 4, !tbaa !9
  br label %6

6:                                                ; preds = %31, %1
  %7 = load ptr, ptr %2, align 8, !tbaa !5
  %8 = load i32, ptr %5, align 4, !tbaa !9
  %9 = sext i32 %8 to i64
  %10 = getelementptr inbounds i8, ptr %7, i64 %9
  %11 = load i8, ptr %10, align 1, !tbaa !11
  %12 = sext i8 %11 to i32
  %13 = icmp ne i32 %12, 0
  br i1 %13, label %14, label %34

14:                                               ; preds = %6
  %15 = load ptr, ptr %2, align 8, !tbaa !5
  %16 = load i32, ptr %5, align 4, !tbaa !9
  %17 = sext i32 %16 to i64
  %18 = getelementptr inbounds i8, ptr %15, i64 %17
  %19 = load i8, ptr %18, align 1, !tbaa !11
  %20 = sext i8 %19 to i32
  %21 = icmp eq i32 %20, 32
  br i1 %21, label %22, label %28

22:                                               ; preds = %14
  %23 = load i32, ptr %3, align 4, !tbaa !9
  %24 = icmp ne i32 %23, 0
  br i1 %24, label %25, label %27

25:                                               ; preds = %22
  %26 = load i32, ptr %3, align 4, !tbaa !9
  store i32 %26, ptr %4, align 4, !tbaa !9
  br label %27

27:                                               ; preds = %25, %22
  store i32 0, ptr %3, align 4, !tbaa !9
  br label %31

28:                                               ; preds = %14
  %29 = load i32, ptr %3, align 4, !tbaa !9
  %30 = add nsw i32 %29, 1
  store i32 %30, ptr %3, align 4, !tbaa !9
  br label %31

31:                                               ; preds = %28, %27
  %32 = load i32, ptr %5, align 4, !tbaa !9
  %33 = add nsw i32 %32, 1
  store i32 %33, ptr %5, align 4, !tbaa !9
  br label %6, !llvm.loop !12

34:                                               ; preds = %6
  %35 = load i32, ptr %3, align 4, !tbaa !9
  %36 = icmp ne i32 %35, 0
  br i1 %36, label %37, label %39

37:                                               ; preds = %34
  %38 = load i32, ptr %3, align 4, !tbaa !9
  store i32 %38, ptr %4, align 4, !tbaa !9
  br label %39

39:                                               ; preds = %37, %34
  %40 = load i32, ptr %4, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #2
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %40
}

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

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

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" }
attributes #1 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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(argmem: read) uwtable
define dso_local i32 @lengthOfLastWord(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  br label %2

2:                                                ; preds = %8, %1
  %indvars.iv = phi i64 [ %indvars.iv.next, %8 ], [ 0, %1 ]
  %.011 = phi i32 [ %.112, %8 ], [ 0, %1 ]
  %.010 = phi i32 [ %.2, %8 ], [ 0, %1 ]
  %3 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv
  %4 = load i8, ptr %3, align 1, !tbaa !5
  switch i8 %4, label %6 [
    i8 0, label %9
    i8 32, label %5
  ]

5:                                                ; preds = %2
  %.not15 = icmp eq i32 %.011, 0
  %spec.select = select i1 %.not15, i32 %.010, i32 %.011
  br label %8

6:                                                ; preds = %2
  %7 = add nsw i32 %.011, 1
  br label %8

8:                                                ; preds = %6, %5
  %.112 = phi i32 [ 0, %5 ], [ %7, %6 ]
  %.2 = phi i32 [ %spec.select, %5 ], [ %.010, %6 ]
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  br label %2, !llvm.loop !8

9:                                                ; preds = %2
  %.not14 = icmp eq i32 %.011, 0
  %spec.select16 = select i1 %.not14, i32 %.010, i32 %.011
  ret i32 %spec.select16
}

attributes #0 = { nofree norecurse nosync nounwind 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" }

!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,GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass