; LLVM IR from begeekmyfriend/leetcode :: 0058_length_of_last_word (word_length)

; 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
  store ptr %0, ptr %2, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %3) #3
  store i32 0, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #3
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = call i64 @strlen(ptr noundef %5) #4
  %7 = trunc i64 %6 to i32
  store i32 %7, ptr %4, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %22, %1
  %9 = load i32, ptr %4, align 4, !tbaa !9
  %10 = icmp sgt i32 %9, 0
  br i1 %10, label %11, label %20

11:                                               ; preds = %8
  %12 = load ptr, ptr %2, align 8, !tbaa !5
  %13 = load i32, ptr %4, align 4, !tbaa !9
  %14 = add nsw i32 %13, -1
  store i32 %14, ptr %4, align 4, !tbaa !9
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds i8, ptr %12, i64 %15
  %17 = load i8, ptr %16, align 1, !tbaa !11
  %18 = sext i8 %17 to i32
  %19 = icmp eq i32 %18, 32
  br label %20

20:                                               ; preds = %11, %8
  %21 = phi i1 [ false, %8 ], [ %19, %11 ]
  br i1 %21, label %22, label %23

22:                                               ; preds = %20
  br label %8, !llvm.loop !12

23:                                               ; preds = %20
  br label %24

24:                                               ; preds = %37, %23
  %25 = load i32, ptr %4, align 4, !tbaa !9
  %26 = icmp sge i32 %25, 0
  br i1 %26, label %27, label %35

27:                                               ; preds = %24
  %28 = load ptr, ptr %2, align 8, !tbaa !5
  %29 = load i32, ptr %4, align 4, !tbaa !9
  %30 = sext i32 %29 to i64
  %31 = getelementptr inbounds i8, ptr %28, i64 %30
  %32 = load i8, ptr %31, align 1, !tbaa !11
  %33 = sext i8 %32 to i32
  %34 = icmp ne i32 %33, 32
  br label %35

35:                                               ; preds = %27, %24
  %36 = phi i1 [ false, %24 ], [ %34, %27 ]
  br i1 %36, label %37, label %42

37:                                               ; preds = %35
  %38 = load i32, ptr %3, align 4, !tbaa !9
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %3, align 4, !tbaa !9
  %40 = load i32, ptr %4, align 4, !tbaa !9
  %41 = add nsw i32 %40, -1
  store i32 %41, ptr %4, align 4, !tbaa !9
  br label %24, !llvm.loop !14

42:                                               ; preds = %35
  %43 = load i32, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 4, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret i32 %43
}

; 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: 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 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/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: nofree nounwind memory(argmem: read) uwtable
define dso_local i32 @lengthOfLastWord(ptr nocapture noundef readonly %0) local_unnamed_addr #0 {
  %2 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %0) #2
  %3 = trunc i64 %2 to i32
  %.old3 = icmp sgt i32 %3, 0
  br i1 %.old3, label %.preheader.preheader, label %.critedge

.preheader.preheader:                             ; preds = %1
  %4 = and i64 %2, 2147483647
  br label %.preheader

.preheader:                                       ; preds = %.preheader.preheader, %.preheader
  %indvars.iv = phi i64 [ %4, %.preheader.preheader ], [ %5, %.preheader ]
  %5 = add nsw i64 %indvars.iv, -1
  %6 = getelementptr inbounds i8, ptr %0, i64 %5
  %7 = load i8, ptr %6, align 1, !tbaa !5
  %8 = icmp eq i8 %7, 32
  %9 = icmp ugt i64 %indvars.iv, 1
  %or.cond = and i1 %9, %8
  br i1 %or.cond, label %.preheader, label %.critedge.loopexit, !llvm.loop !8

.critedge.loopexit:                               ; preds = %.preheader
  %10 = trunc i64 %5 to i32
  br label %.critedge

.critedge:                                        ; preds = %.critedge.loopexit, %1
  %.1 = phi i32 [ %3, %1 ], [ %10, %.critedge.loopexit ]
  %11 = icmp sgt i32 %.1, -1
  br i1 %11, label %.lr.ph.preheader, label %.critedge2

.lr.ph.preheader:                                 ; preds = %.critedge
  %12 = add nuw i32 %.1, 1
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %16
  %.217 = phi i32 [ %18, %16 ], [ %.1, %.lr.ph.preheader ]
  %.01316 = phi i32 [ %17, %16 ], [ 0, %.lr.ph.preheader ]
  %13 = zext nneg i32 %.217 to i64
  %14 = getelementptr inbounds i8, ptr %0, i64 %13
  %15 = load i8, ptr %14, align 1, !tbaa !5
  %.not = icmp eq i8 %15, 32
  br i1 %.not, label %.critedge2, label %16

16:                                               ; preds = %.lr.ph
  %17 = add nuw i32 %.01316, 1
  %18 = add nsw i32 %.217, -1
  %exitcond.not = icmp eq i32 %.01316, %.1
  br i1 %exitcond.not, label %.critedge2, label %.lr.ph, !llvm.loop !10

.critedge2:                                       ; preds = %.lr.ph, %16, %.critedge
  %.013.lcssa = phi i32 [ 0, %.critedge ], [ %12, %16 ], [ %.01316, %.lr.ph ]
  ret i32 %.013.lcssa
}

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

attributes #0 = { nofree 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" }
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 = { 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 = !{!"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: CorrelatedValuePropagationPass,GVNPass,GlobalOptPass,IPSCCPPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,JumpThreadingPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,ReassociatePass,SROAPass,SimplifyCFGPass,TailCallElimPass