; LLVM IR from div-bargali/Data-Structures-and-Algorithms :: C++/Algorithms/Pattern-Searching (boyermoore)

; 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 void @_Z16badCharHeuristicNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiPi(ptr noundef %0, i32 noundef %1, ptr noundef %2) #0 {
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca ptr, align 8
  %7 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store i32 %1, ptr %5, align 4, !tbaa !9
  store ptr %2, ptr %6, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #3
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %8

8:                                                ; preds = %16, %3
  %9 = load i32, ptr %7, align 4, !tbaa !9
  %10 = icmp slt i32 %9, 256
  br i1 %10, label %11, label %19

11:                                               ; preds = %8
  %12 = load ptr, ptr %6, align 8, !tbaa !5
  %13 = load i32, ptr %7, align 4, !tbaa !9
  %14 = sext i32 %13 to i64
  %15 = getelementptr inbounds i32, ptr %12, i64 %14
  store i32 -1, ptr %15, align 4, !tbaa !9
  br label %16

16:                                               ; preds = %11
  %17 = load i32, ptr %7, align 4, !tbaa !9
  %18 = add nsw i32 %17, 1
  store i32 %18, ptr %7, align 4, !tbaa !9
  br label %8, !llvm.loop !11

19:                                               ; preds = %8
  store i32 0, ptr %7, align 4, !tbaa !9
  br label %20

20:                                               ; preds = %34, %19
  %21 = load i32, ptr %7, align 4, !tbaa !9
  %22 = load i32, ptr %5, align 4, !tbaa !9
  %23 = icmp slt i32 %21, %22
  br i1 %23, label %24, label %37

24:                                               ; preds = %20
  %25 = load i32, ptr %7, align 4, !tbaa !9
  %26 = load ptr, ptr %6, align 8, !tbaa !5
  %27 = load i32, ptr %7, align 4, !tbaa !9
  %28 = sext i32 %27 to i64
  %29 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %28)
  %30 = load i8, ptr %29, align 1, !tbaa !13
  %31 = sext i8 %30 to i32
  %32 = sext i32 %31 to i64
  %33 = getelementptr inbounds i32, ptr %26, i64 %32
  store i32 %25, ptr %33, align 4, !tbaa !9
  br label %34

34:                                               ; preds = %24
  %35 = load i32, ptr %7, align 4, !tbaa !9
  %36 = add nsw i32 %35, 1
  store i32 %36, ptr %7, align 4, !tbaa !9
  br label %20, !llvm.loop !14

37:                                               ; preds = %20
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #3
  ret void
}

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

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) #2 align 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 = { 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 #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 = distinct !{!11, !12}
!12 = !{!"llvm.loop.mustprogress"}
!13 = !{!7, !7, i64 0}
!14 = distinct !{!14, !12}


; 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 nounwind uwtable
define dso_local void @_Z16badCharHeuristicNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEiPi(ptr noundef %0, i32 noundef %1, ptr nocapture noundef writeonly %2) local_unnamed_addr #0 {
.preheader:
  tail call void @llvm.memset.p0.i64(ptr noundef nonnull align 4 dereferenceable(1024) %2, i8 -1, i64 1024, i1 false), !tbaa !5
  %3 = icmp sgt i32 %1, 0
  br i1 %3, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %.preheader
  %wide.trip.count = zext nneg i32 %1 to i64
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.lr.ph
  %indvars.iv = phi i64 [ 0, %.lr.ph.preheader ], [ %indvars.iv.next, %.lr.ph ]
  %4 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %0, i64 noundef %indvars.iv)
  %5 = load i8, ptr %4, align 1, !tbaa !9
  %6 = sext i8 %5 to i64
  %7 = getelementptr inbounds i32, ptr %2, i64 %6
  %8 = trunc nuw nsw i64 %indvars.iv to i32
  store i32 %8, ptr %7, align 4, !tbaa !5
  %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 !10

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

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) local_unnamed_addr #0 align 2

; Function Attrs: nocallback nofree nounwind willreturn memory(argmem: write)
declare void @llvm.memset.p0.i64(ptr nocapture writeonly, i8, i64, i1 immarg) #1

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" }
attributes #1 = { nocallback nofree nounwind willreturn memory(argmem: write) }

!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 = !{!7, !7, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}


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