; LLVM IR from thefatihcinar/strings-exercises :: Solutions/Trim Leading and Trailing White Spaces From a Given String (trimTrailingWhiteSpaces)

; 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
declare dso_local i32 @isWhiteSpace(i8 noundef signext) #0

; 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

; Function Attrs: nounwind uwtable
define dso_local void @trimTrailingWhiteSpaces(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
  call void @llvm.lifetime.start.p0(i64 4, ptr %4) #2
  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 = %14, %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 %17

14:                                               ; preds = %6
  %15 = load i32, ptr %5, align 4, !tbaa !9
  %16 = add nsw i32 %15, 1
  store i32 %16, ptr %5, align 4, !tbaa !9
  br label %6, !llvm.loop !12

17:                                               ; preds = %6
  %18 = load i32, ptr %5, align 4, !tbaa !9
  store i32 %18, ptr %4, align 4, !tbaa !9
  %19 = load i32, ptr %4, align 4, !tbaa !9
  %20 = sub nsw i32 %19, 1
  store i32 %20, ptr %5, align 4, !tbaa !9
  br label %21

21:                                               ; preds = %30, %17
  %22 = load ptr, ptr %2, align 8, !tbaa !5
  %23 = load i32, ptr %5, align 4, !tbaa !9
  %24 = sext i32 %23 to i64
  %25 = getelementptr inbounds i8, ptr %22, i64 %24
  %26 = load i8, ptr %25, align 1, !tbaa !11
  %27 = call i32 @isWhiteSpace(i8 noundef signext %26)
  %28 = icmp ne i32 %27, 0
  br i1 %28, label %29, label %33

29:                                               ; preds = %21
  br label %30

30:                                               ; preds = %29
  %31 = load i32, ptr %5, align 4, !tbaa !9
  %32 = add nsw i32 %31, -1
  store i32 %32, ptr %5, align 4, !tbaa !9
  br label %21, !llvm.loop !14

33:                                               ; preds = %21
  %34 = load i32, ptr %5, align 4, !tbaa !9
  store i32 %34, ptr %3, align 4, !tbaa !9
  %35 = load ptr, ptr %2, align 8, !tbaa !5
  %36 = load i32, ptr %3, align 4, !tbaa !9
  %37 = add nsw i32 %36, 1
  %38 = sext i32 %37 to i64
  %39 = getelementptr inbounds i8, ptr %35, i64 %38
  store i8 0, ptr %39, align 1, !tbaa !11
  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 void
}

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"}
!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: nounwind uwtable
declare dso_local i32 @isWhiteSpace(i8 noundef signext) local_unnamed_addr #0

; Function Attrs: nounwind uwtable
define dso_local void @trimTrailingWhiteSpaces(ptr nocapture noundef %0) local_unnamed_addr #0 {
  br label %2

2:                                                ; preds = %2, %1
  %indvars.iv = phi i64 [ %indvars.iv.next, %2 ], [ 0, %1 ]
  %3 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv
  %4 = load i8, ptr %3, align 1, !tbaa !5
  %.not = icmp eq i8 %4, 0
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  br i1 %.not, label %.preheader, label %2, !llvm.loop !8

.preheader:                                       ; preds = %2, %.preheader
  %indvars.iv12 = phi i64 [ %indvars.iv.next13, %.preheader ], [ %indvars.iv, %2 ]
  %indvars.iv.next13 = add nsw i64 %indvars.iv12, -1
  %5 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv.next13
  %6 = load i8, ptr %5, align 1, !tbaa !5
  %7 = tail call i32 @isWhiteSpace(i8 noundef signext %6)
  %.not10 = icmp eq i32 %7, 0
  br i1 %.not10, label %8, label %.preheader, !llvm.loop !10

8:                                                ; preds = %.preheader
  %sext = shl i64 %indvars.iv12, 32
  %9 = ashr exact i64 %sext, 32
  %10 = getelementptr inbounds i8, ptr %0, i64 %9
  store i8 0, ptr %10, align 1, !tbaa !5
  ret void
}

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" }

!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: GVNPass,GlobalOptPass,IndVarSimplifyPass,InferFunctionAttrsPass,InstCombinePass,InstSimplifyPass,LCSSAPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass