; LLVM IR from satu0king/Leetcode-Solutions :: solutions/58.length-of-last-word.328654920.ac (lengthOfLastWord)

; 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
  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
  br label %4

4:                                                ; preds = %29, %1
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = load i8, ptr %5, align 1, !tbaa !11
  %7 = icmp ne i8 %6, 0
  br i1 %7, label %8, label %30

8:                                                ; preds = %4
  %9 = load ptr, ptr %2, align 8, !tbaa !5
  %10 = getelementptr inbounds i8, ptr %9, i32 1
  store ptr %10, ptr %2, align 8, !tbaa !5
  %11 = load i8, ptr %9, align 1, !tbaa !11
  %12 = sext i8 %11 to i32
  %13 = icmp ne i32 %12, 32
  br i1 %13, label %14, label %17

14:                                               ; preds = %8
  %15 = load i32, ptr %3, align 4, !tbaa !9
  %16 = add nsw i32 %15, 1
  store i32 %16, ptr %3, align 4, !tbaa !9
  br label %29

17:                                               ; preds = %8
  %18 = load ptr, ptr %2, align 8, !tbaa !5
  %19 = load i8, ptr %18, align 1, !tbaa !11
  %20 = sext i8 %19 to i32
  %21 = icmp ne i32 %20, 0
  br i1 %21, label %22, label %28

22:                                               ; preds = %17
  %23 = load ptr, ptr %2, align 8, !tbaa !5
  %24 = load i8, ptr %23, align 1, !tbaa !11
  %25 = sext i8 %24 to i32
  %26 = icmp ne i32 %25, 32
  br i1 %26, label %27, label %28

27:                                               ; preds = %22
  store i32 0, ptr %3, align 4, !tbaa !9
  br label %28

28:                                               ; preds = %27, %22, %17
  br label %29

29:                                               ; preds = %28, %14
  br label %4, !llvm.loop !12

30:                                               ; preds = %4
  %31 = load i32, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #2
  ret i32 %31
}

; 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(read, inaccessiblemem: none) uwtable
define dso_local i32 @lengthOfLastWord(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %2 = load i8, ptr %0, align 1, !tbaa !5
  %.not11 = icmp eq i8 %2, 0
  br i1 %.not11, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %10
  %3 = phi i8 [ %11, %10 ], [ %2, %1 ]
  %.013 = phi i32 [ %.1, %10 ], [ 0, %1 ]
  %.0512 = phi ptr [ %4, %10 ], [ %0, %1 ]
  %4 = getelementptr inbounds i8, ptr %.0512, i64 1
  %.not8 = icmp eq i8 %3, 32
  br i1 %.not8, label %7, label %5

5:                                                ; preds = %.lr.ph
  %6 = add nsw i32 %.013, 1
  %.pre = load i8, ptr %4, align 1, !tbaa !5
  br label %10

7:                                                ; preds = %.lr.ph
  %8 = load i8, ptr %4, align 1, !tbaa !5
  switch i8 %8, label %9 [
    i8 0, label %10
    i8 32, label %10
  ]

9:                                                ; preds = %7
  br label %10

10:                                               ; preds = %7, %7, %9, %5
  %11 = phi i8 [ %.pre, %5 ], [ %8, %9 ], [ %8, %7 ], [ %8, %7 ]
  %.1 = phi i32 [ %6, %5 ], [ 0, %9 ], [ %.013, %7 ], [ %.013, %7 ]
  %.not = icmp eq i8 %11, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !8

._crit_edge:                                      ; preds = %10, %1
  %.0.lcssa = phi i32 [ 0, %1 ], [ %.1, %10 ]
  ret i32 %.0.lcssa
}

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,GVNPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass