; LLVM IR from ippeb/ACM-ICPC :: dynamic_programming/LCS/subseq.ll (Z6subseqPcS_)

; 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 nounwind uwtable
define dso_local noundef i32 @_Z6subseqPcS_(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  br label %6

6:                                                ; preds = %27, %2
  %7 = load ptr, ptr %5, align 8, !tbaa !5
  %8 = load i8, ptr %7, align 1, !tbaa !9
  %9 = sext i8 %8 to i32
  %10 = icmp ne i32 %9, 0
  br i1 %10, label %11, label %28

11:                                               ; preds = %6
  %12 = load ptr, ptr %4, align 8, !tbaa !5
  %13 = load i8, ptr %12, align 1, !tbaa !9
  %14 = sext i8 %13 to i32
  %15 = load ptr, ptr %5, align 8, !tbaa !5
  %16 = getelementptr inbounds i8, ptr %15, i32 1
  store ptr %16, ptr %5, align 8, !tbaa !5
  %17 = load i8, ptr %15, align 1, !tbaa !9
  %18 = sext i8 %17 to i32
  %19 = icmp eq i32 %14, %18
  br i1 %19, label %20, label %27

20:                                               ; preds = %11
  %21 = load ptr, ptr %4, align 8, !tbaa !5
  %22 = getelementptr inbounds i8, ptr %21, i32 1
  store ptr %22, ptr %4, align 8, !tbaa !5
  %23 = load i8, ptr %22, align 1, !tbaa !9
  %24 = sext i8 %23 to i32
  %25 = icmp eq i32 %24, 0
  br i1 %25, label %26, label %27

26:                                               ; preds = %20
  store i32 1, ptr %3, align 4
  br label %29

27:                                               ; preds = %20, %11
  br label %6, !llvm.loop !10

28:                                               ; preds = %6
  store i32 0, ptr %3, align 4
  br label %29

29:                                               ; preds = %28, %26
  %30 = load i32, ptr %3, align 4
  ret i32 %30
}

attributes #0 = { 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" }

!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 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"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 norecurse nosync nounwind willreturn memory(read, inaccessiblemem: none) uwtable
define dso_local noundef range(i32 0, 2) i32 @_Z6subseqPcS_(ptr nocapture noundef readonly %0, ptr nocapture noundef readonly %1) local_unnamed_addr #0 {
  %3 = load i8, ptr %1, align 1, !tbaa !5
  %.not7 = icmp eq i8 %3, 0
  br i1 %.not7, label %._crit_edge, label %.lr.ph.preheader

.lr.ph.preheader:                                 ; preds = %2
  %.pre = load i8, ptr %0, align 1, !tbaa !5
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %12
  %4 = phi i8 [ %13, %12 ], [ %.pre, %.lr.ph.preheader ]
  %5 = phi i8 [ %14, %12 ], [ %3, %.lr.ph.preheader ]
  %.09 = phi ptr [ %6, %12 ], [ %1, %.lr.ph.preheader ]
  %.048 = phi ptr [ %.1, %12 ], [ %0, %.lr.ph.preheader ]
  %6 = getelementptr inbounds i8, ptr %.09, i64 1
  %7 = icmp eq i8 %4, %5
  br i1 %7, label %8, label %12

8:                                                ; preds = %.lr.ph
  %9 = getelementptr inbounds i8, ptr %.048, i64 1
  %10 = load i8, ptr %9, align 1, !tbaa !5
  %11 = icmp eq i8 %10, 0
  br i1 %11, label %._crit_edge, label %12

12:                                               ; preds = %8, %.lr.ph
  %13 = phi i8 [ %10, %8 ], [ %4, %.lr.ph ]
  %.1 = phi ptr [ %9, %8 ], [ %.048, %.lr.ph ]
  %14 = load i8, ptr %6, align 1, !tbaa !5
  %.not = icmp eq i8 %14, 0
  br i1 %.not, label %._crit_edge, label %.lr.ph, !llvm.loop !8

._crit_edge:                                      ; preds = %8, %12, %2
  %.05 = phi i32 [ 0, %2 ], [ 0, %12 ], [ 1, %8 ]
  ret i32 %.05
}

attributes #0 = { mustprogress nofree norecurse nosync nounwind willreturn memory(read, 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" }

!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: EarlyCSEPass,GVNPass,GlobalOptPass,IPSCCPPass,InstCombinePass,JumpThreadingPass,LoopRotatePass,LoopSimplifyPass,LoopUnrollPass,PostOrderFunctionAttrsPass,SROAPass,SimplifyCFGPass