; LLVM IR from Ayon-SSP/The-SDE-Prep :: 1]_Data Structures/3]_Stack (StringPalindromeusingstack)

; 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"

%struct.node = type { i8, ptr }

@.str.2 = external hidden unnamed_addr constant [31 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [4 x i8], align 1

declare i32 @printf(ptr noundef, ...) #0

; Function Attrs: nounwind uwtable
define dso_local void @printStack(ptr noundef %0) #1 {
  %2 = alloca ptr, align 8
  store ptr %0, ptr %2, align 8, !tbaa !5
  %3 = call i32 (ptr, ...) @printf(ptr noundef @.str.2)
  br label %4

4:                                                ; preds = %7, %1
  %5 = load ptr, ptr %2, align 8, !tbaa !5
  %6 = icmp ne ptr %5, null
  br i1 %6, label %7, label %16

7:                                                ; preds = %4
  %8 = load ptr, ptr %2, align 8, !tbaa !5
  %9 = getelementptr inbounds %struct.node, ptr %8, i32 0, i32 0
  %10 = load i8, ptr %9, align 8, !tbaa !9
  %11 = sext i8 %10 to i32
  %12 = call i32 (ptr, ...) @printf(ptr noundef @.str.3, i32 noundef %11)
  %13 = load ptr, ptr %2, align 8, !tbaa !5
  %14 = getelementptr inbounds %struct.node, ptr %13, i32 0, i32 1
  %15 = load ptr, ptr %14, align 8, !tbaa !11
  store ptr %15, ptr %2, align 8, !tbaa !5
  br label %4, !llvm.loop !12

16:                                               ; preds = %4
  ret void
}

attributes #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 = { 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 = !{!"any pointer", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!10, !7, i64 0}
!10 = !{!"node", !7, i64 0, !6, i64 8}
!11 = !{!10, !6, i64 8}
!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"

@.str.2 = external hidden unnamed_addr constant [31 x i8], align 1
@.str.3 = external hidden unnamed_addr constant [4 x i8], align 1

; Function Attrs: nofree nounwind
declare noundef i32 @printf(ptr nocapture noundef readonly, ...) local_unnamed_addr #0

; Function Attrs: nofree nounwind uwtable
define dso_local void @printStack(ptr noundef readonly %0) local_unnamed_addr #1 {
  %2 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.2)
  %.not3 = icmp eq ptr %0, null
  br i1 %.not3, label %._crit_edge, label %.lr.ph

.lr.ph:                                           ; preds = %1, %.lr.ph
  %.04 = phi ptr [ %7, %.lr.ph ], [ %0, %1 ]
  %3 = load i8, ptr %.04, align 8, !tbaa !5
  %4 = sext i8 %3 to i32
  %5 = tail call i32 (ptr, ...) @printf(ptr noundef nonnull dereferenceable(1) @.str.3, i32 noundef %4)
  %6 = getelementptr inbounds i8, ptr %.04, i64 8
  %7 = load ptr, ptr %6, align 8, !tbaa !10
  %.not = icmp eq ptr %7, null
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !11

._crit_edge:                                      ; preds = %.lr.ph, %1
  ret void
}

attributes #0 = { nofree nounwind "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 = { 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, !7, i64 0}
!6 = !{!"node", !7, i64 0, !9, i64 8}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C/C++ TBAA"}
!9 = !{!"any pointer", !7, i64 0}
!10 = !{!6, !9, i64 8}
!11 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}


; Effective O3 passes: EarlyCSEPass,GlobalOptPass,InferFunctionAttrsPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass,TailCallElimPass