; LLVM IR from NishkarshRaj/Design-and-Analysis-of-Algorithms :: Backtracking/Nqueen.ll (Z5placeii)

; 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"

@board = external dso_local global [20 x i32], align 16

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #0

; Function Attrs: mustprogress nounwind uwtable
define dso_local noundef i32 @_Z5placeii(i32 noundef %0, i32 noundef %1) #1 {
  %3 = alloca i32, align 4
  %4 = alloca i32, align 4
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store i32 %0, ptr %4, align 4, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #3
  store i32 1, ptr %6, align 4, !tbaa !5
  br label %8

8:                                                ; preds = %37, %2
  %9 = load i32, ptr %6, align 4, !tbaa !5
  %10 = load i32, ptr %4, align 4, !tbaa !5
  %11 = sub nsw i32 %10, 1
  %12 = icmp sle i32 %9, %11
  br i1 %12, label %13, label %40

13:                                               ; preds = %8
  %14 = load i32, ptr %6, align 4, !tbaa !5
  %15 = sext i32 %14 to i64
  %16 = getelementptr inbounds [20 x i32], ptr @board, i64 0, i64 %15
  %17 = load i32, ptr %16, align 4, !tbaa !5
  %18 = load i32, ptr %5, align 4, !tbaa !5
  %19 = icmp eq i32 %17, %18
  br i1 %19, label %20, label %21

20:                                               ; preds = %13
  store i32 0, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %41

21:                                               ; preds = %13
  %22 = load i32, ptr %6, align 4, !tbaa !5
  %23 = sext i32 %22 to i64
  %24 = getelementptr inbounds [20 x i32], ptr @board, i64 0, i64 %23
  %25 = load i32, ptr %24, align 4, !tbaa !5
  %26 = load i32, ptr %5, align 4, !tbaa !5
  %27 = sub nsw i32 %25, %26
  %28 = call i32 @llvm.abs.i32(i32 %27, i1 true)
  %29 = load i32, ptr %6, align 4, !tbaa !5
  %30 = load i32, ptr %4, align 4, !tbaa !5
  %31 = sub nsw i32 %29, %30
  %32 = call i32 @llvm.abs.i32(i32 %31, i1 true)
  %33 = icmp eq i32 %28, %32
  br i1 %33, label %34, label %35

34:                                               ; preds = %21
  store i32 0, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %41

35:                                               ; preds = %21
  br label %36

36:                                               ; preds = %35
  br label %37

37:                                               ; preds = %36
  %38 = load i32, ptr %6, align 4, !tbaa !5
  %39 = add nsw i32 %38, 1
  store i32 %39, ptr %6, align 4, !tbaa !5
  br label %8, !llvm.loop !9

40:                                               ; preds = %8
  store i32 1, ptr %3, align 4
  store i32 1, ptr %7, align 4
  br label %41

41:                                               ; preds = %40, %34, %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #3
  %42 = load i32, ptr %3, align 4
  ret i32 %42
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.abs.i32(i32, i1 immarg) #2

attributes #0 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #1 = { mustprogress 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 #2 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
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 = !{!"int", !7, i64 0}
!7 = !{!"omnipotent char", !8, i64 0}
!8 = !{!"Simple C++ TBAA"}
!9 = distinct !{!9, !10}
!10 = !{!"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"

@board = external dso_local local_unnamed_addr global [20 x i32], align 16

; Function Attrs: mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, inaccessiblemem: none) uwtable
define dso_local noundef range(i32 0, 2) i32 @_Z5placeii(i32 noundef %0, i32 noundef %1) local_unnamed_addr #0 {
  %.not.not13 = icmp sgt i32 %0, 1
  br i1 %.not.not13, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %wide.trip.count = zext nneg i32 %0 to i64
  br label %.lr.ph

3:                                                ; preds = %7
  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
  %exitcond.not = icmp eq i64 %indvars.iv.next, %wide.trip.count
  br i1 %exitcond.not, label %._crit_edge, label %.lr.ph, !llvm.loop !5

.lr.ph:                                           ; preds = %.lr.ph.preheader, %3
  %indvars.iv = phi i64 [ 1, %.lr.ph.preheader ], [ %indvars.iv.next, %3 ]
  %4 = getelementptr inbounds [20 x i32], ptr @board, i64 0, i64 %indvars.iv
  %5 = load i32, ptr %4, align 4, !tbaa !7
  %6 = icmp eq i32 %5, %1
  br i1 %6, label %._crit_edge, label %7

7:                                                ; preds = %.lr.ph
  %8 = sub nsw i32 %5, %1
  %9 = tail call i32 @llvm.abs.i32(i32 %8, i1 true)
  %10 = trunc i64 %indvars.iv to i32
  %11 = sub i32 %10, %0
  %12 = tail call i32 @llvm.abs.i32(i32 %11, i1 true)
  %13 = icmp eq i32 %9, %12
  br i1 %13, label %._crit_edge, label %3

._crit_edge:                                      ; preds = %.lr.ph, %7, %3, %2
  %.010 = phi i32 [ 1, %2 ], [ 1, %3 ], [ 0, %7 ], [ 0, %.lr.ph ]
  ret i32 %.010
}

; Function Attrs: mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i32 @llvm.abs.i32(i32, i1 immarg) #1

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, argmem: none, 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" }
attributes #1 = { mustprogress nocallback nofree nosync nounwind speculatable willreturn memory(none) }

!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 = distinct !{!5, !6}
!6 = !{!"llvm.loop.mustprogress"}
!7 = !{!8, !8, i64 0}
!8 = !{!"int", !9, i64 0}
!9 = !{!"omnipotent char", !10, i64 0}
!10 = !{!"Simple C++ TBAA"}


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