; LLVM IR from ritikbanger/Hacktoberfest2022-DSA :: 11. Stack/EqualStacks.ll (Z8readlinePc)

; 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 uwtable
define dso_local noundef i32 @_Z8readlinePc(ptr noundef %0) #0 {
  %2 = alloca ptr, align 8
  %3 = alloca i32, align 4
  %4 = alloca i8, align 1
  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 1, ptr %4) #3
  br label %5

5:                                                ; preds = %10, %1
  %6 = call i32 @getchar()
  %7 = trunc i32 %6 to i8
  store i8 %7, ptr %4, align 1, !tbaa !11
  %8 = sext i8 %7 to i32
  %9 = icmp ne i32 %8, 10
  br i1 %9, label %10, label %17

10:                                               ; preds = %5
  %11 = load i8, ptr %4, align 1, !tbaa !11
  %12 = load ptr, ptr %2, align 8, !tbaa !5
  %13 = load i32, ptr %3, align 4, !tbaa !9
  %14 = add nsw i32 %13, 1
  store i32 %14, ptr %3, align 4, !tbaa !9
  %15 = sext i32 %13 to i64
  %16 = getelementptr inbounds i8, ptr %12, i64 %15
  store i8 %11, ptr %16, align 1, !tbaa !11
  br label %5, !llvm.loop !12

17:                                               ; preds = %5
  %18 = load ptr, ptr %2, align 8, !tbaa !5
  %19 = load i32, ptr %3, align 4, !tbaa !9
  %20 = sext i32 %19 to i64
  %21 = getelementptr inbounds i8, ptr %18, i64 %20
  store i8 0, ptr %21, align 1, !tbaa !11
  %22 = load i32, ptr %3, align 4, !tbaa !9
  call void @llvm.lifetime.end.p0(i64 1, ptr %4) #3
  call void @llvm.lifetime.end.p0(i64 4, ptr %3) #3
  ret i32 %22
}

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

; Function Attrs: inlinehint mustprogress uwtable
declare i32 @getchar() #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 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 = { inlinehint mustprogress 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 #3 = { 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++ 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: mustprogress nofree nounwind uwtable
define dso_local noundef i32 @_Z8readlinePc(ptr nocapture noundef writeonly %0) local_unnamed_addr #0 {
  %2 = tail call i32 @getchar()
  %sext.mask5 = and i32 %2, 255
  %.not6 = icmp eq i32 %sext.mask5, 10
  br i1 %.not6, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %indvars.iv = phi i64 [ %indvars.iv.next, %.lr.ph ], [ 0, %1 ]
  %3 = phi i32 [ %6, %.lr.ph ], [ %2, %1 ]
  %4 = trunc i32 %3 to i8
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %5 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv
  store i8 %4, ptr %5, align 1, !tbaa !5
  %6 = tail call i32 @getchar()
  %sext.mask = and i32 %6, 255
  %.not = icmp eq i32 %sext.mask, 10
  br i1 %.not, label %._crit_edge.loopexit, label %.lr.ph, !llvm.loop !8

._crit_edge.loopexit:                             ; preds = %.lr.ph
  %7 = trunc nuw i64 %indvars.iv.next to i32
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.loopexit, %1
  %.0.lcssa = phi i32 [ 0, %1 ], [ %7, %._crit_edge.loopexit ]
  %8 = zext nneg i32 %.0.lcssa to i64
  %9 = getelementptr inbounds i8, ptr %0, i64 %8
  store i8 0, ptr %9, align 1, !tbaa !5
  ret i32 %.0.lcssa
}

; Function Attrs: inlinehint mustprogress nofree nounwind uwtable
declare noundef i32 @getchar() local_unnamed_addr #1

attributes #0 = { mustprogress nofree 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 = { inlinehint mustprogress nofree 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++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


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