; LLVM IR from gzc/CLRS :: C32-String-Matching (KMP)

; 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: nounwind uwtable
declare dso_local ptr @compute_prefix_function(ptr noundef) #0

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

; Function Attrs: nounwind willreturn memory(read)
declare i64 @strlen(ptr noundef) #2

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

; Function Attrs: nounwind uwtable
define dso_local i32 @KMP_match(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca i32, align 4
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  %8 = alloca ptr, align 8
  %9 = alloca i32, align 4
  %10 = alloca i32, align 4
  %11 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #4
  %12 = load ptr, ptr %4, align 8, !tbaa !5
  %13 = call i64 @strlen(ptr noundef %12) #5
  %14 = trunc i64 %13 to i32
  store i32 %14, ptr %6, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %7) #4
  %15 = load ptr, ptr %5, align 8, !tbaa !5
  %16 = call i64 @strlen(ptr noundef %15) #5
  %17 = trunc i64 %16 to i32
  store i32 %17, ptr %7, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 8, ptr %8) #4
  %18 = load ptr, ptr %5, align 8, !tbaa !5
  %19 = call ptr @compute_prefix_function(ptr noundef %18)
  store ptr %19, ptr %8, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %9) #4
  store i32 0, ptr %9, align 4, !tbaa !9
  call void @llvm.lifetime.start.p0(i64 4, ptr %10) #4
  store i32 0, ptr %10, align 4, !tbaa !9
  br label %20

20:                                               ; preds = %78, %2
  %21 = load i32, ptr %10, align 4, !tbaa !9
  %22 = load i32, ptr %6, align 4, !tbaa !9
  %23 = icmp slt i32 %21, %22
  br i1 %23, label %24, label %81

24:                                               ; preds = %20
  br label %25

25:                                               ; preds = %44, %24
  %26 = load i32, ptr %9, align 4, !tbaa !9
  %27 = icmp sgt i32 %26, 0
  br i1 %27, label %28, label %42

28:                                               ; preds = %25
  %29 = load ptr, ptr %5, align 8, !tbaa !5
  %30 = load i32, ptr %9, align 4, !tbaa !9
  %31 = sext i32 %30 to i64
  %32 = getelementptr inbounds i8, ptr %29, i64 %31
  %33 = load i8, ptr %32, align 1, !tbaa !11
  %34 = sext i8 %33 to i32
  %35 = load ptr, ptr %4, align 8, !tbaa !5
  %36 = load i32, ptr %10, align 4, !tbaa !9
  %37 = sext i32 %36 to i64
  %38 = getelementptr inbounds i8, ptr %35, i64 %37
  %39 = load i8, ptr %38, align 1, !tbaa !11
  %40 = sext i8 %39 to i32
  %41 = icmp ne i32 %34, %40
  br label %42

42:                                               ; preds = %28, %25
  %43 = phi i1 [ false, %25 ], [ %41, %28 ]
  br i1 %43, label %44, label %51

44:                                               ; preds = %42
  %45 = load ptr, ptr %8, align 8, !tbaa !5
  %46 = load i32, ptr %9, align 4, !tbaa !9
  %47 = sub nsw i32 %46, 1
  %48 = sext i32 %47 to i64
  %49 = getelementptr inbounds i32, ptr %45, i64 %48
  %50 = load i32, ptr %49, align 4, !tbaa !9
  store i32 %50, ptr %9, align 4, !tbaa !9
  br label %25, !llvm.loop !12

51:                                               ; preds = %42
  %52 = load ptr, ptr %5, align 8, !tbaa !5
  %53 = load i32, ptr %9, align 4, !tbaa !9
  %54 = sext i32 %53 to i64
  %55 = getelementptr inbounds i8, ptr %52, i64 %54
  %56 = load i8, ptr %55, align 1, !tbaa !11
  %57 = sext i8 %56 to i32
  %58 = load ptr, ptr %4, align 8, !tbaa !5
  %59 = load i32, ptr %10, align 4, !tbaa !9
  %60 = sext i32 %59 to i64
  %61 = getelementptr inbounds i8, ptr %58, i64 %60
  %62 = load i8, ptr %61, align 1, !tbaa !11
  %63 = sext i8 %62 to i32
  %64 = icmp eq i32 %57, %63
  br i1 %64, label %65, label %68

65:                                               ; preds = %51
  %66 = load i32, ptr %9, align 4, !tbaa !9
  %67 = add nsw i32 %66, 1
  store i32 %67, ptr %9, align 4, !tbaa !9
  br label %68

68:                                               ; preds = %65, %51
  %69 = load i32, ptr %9, align 4, !tbaa !9
  %70 = load i32, ptr %7, align 4, !tbaa !9
  %71 = icmp eq i32 %69, %70
  br i1 %71, label %72, label %77

72:                                               ; preds = %68
  %73 = load i32, ptr %10, align 4, !tbaa !9
  %74 = add nsw i32 %73, 1
  %75 = load i32, ptr %7, align 4, !tbaa !9
  %76 = sub nsw i32 %74, %75
  store i32 %76, ptr %3, align 4
  store i32 1, ptr %11, align 4
  br label %83

77:                                               ; preds = %68
  br label %78

78:                                               ; preds = %77
  %79 = load i32, ptr %10, align 4, !tbaa !9
  %80 = add nsw i32 %79, 1
  store i32 %80, ptr %10, align 4, !tbaa !9
  br label %20, !llvm.loop !14

81:                                               ; preds = %20
  %82 = load ptr, ptr %8, align 8, !tbaa !5
  call void @free(ptr noundef %82) #4
  store i32 -1, ptr %3, align 4
  store i32 1, ptr %11, align 4
  br label %83

83:                                               ; preds = %81, %72
  call void @llvm.lifetime.end.p0(i64 4, ptr %10) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %9) #4
  call void @llvm.lifetime.end.p0(i64 8, ptr %8) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %7) #4
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #4
  %84 = load i32, ptr %3, align 4
  ret i32 %84
}

; Function Attrs: nounwind
declare void @free(ptr noundef) #3

attributes #0 = { 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 nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { nounwind willreturn memory(read) "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 "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 #4 = { nounwind }
attributes #5 = { nounwind willreturn memory(read) }

!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, !10, i64 0}
!10 = !{!"int", !7, i64 0}
!11 = !{!7, !7, i64 0}
!12 = distinct !{!12, !13}
!13 = !{!"llvm.loop.mustprogress"}
!14 = distinct !{!14, !13}


; 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: nounwind uwtable
declare dso_local ptr @compute_prefix_function(ptr noundef) local_unnamed_addr #0

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: read)
declare i64 @strlen(ptr nocapture noundef) local_unnamed_addr #1

; Function Attrs: nounwind uwtable
define dso_local i32 @KMP_match(ptr nocapture noundef readonly %0, ptr noundef %1) local_unnamed_addr #0 {
  %3 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %0) #3
  %4 = trunc i64 %3 to i32
  %5 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) #3
  %6 = trunc i64 %5 to i32
  %7 = tail call ptr @compute_prefix_function(ptr noundef %1)
  %8 = icmp sgt i32 %4, 0
  br i1 %8, label %.preheader.lr.ph, label %._crit_edge

.preheader.lr.ph:                                 ; preds = %2
  %invariant.gep = getelementptr i8, ptr %7, i64 -4
  %wide.trip.count = and i64 %3, 2147483647
  br label %.preheader

.preheader:                                       ; preds = %.preheader.lr.ph, %27
  %indvars.iv = phi i64 [ 0, %.preheader.lr.ph ], [ %indvars.iv.next, %27 ]
  %.02330 = phi i32 [ 0, %.preheader.lr.ph ], [ %spec.select, %27 ]
  %9 = icmp sgt i32 %.02330, 0
  %10 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv
  %11 = load i8, ptr %10, align 1, !tbaa !5
  br i1 %9, label %.lr.ph, label %.critedge

.lr.ph:                                           ; preds = %.preheader, %15
  %.127 = phi i32 [ %16, %15 ], [ %.02330, %.preheader ]
  %12 = zext nneg i32 %.127 to i64
  %13 = getelementptr inbounds i8, ptr %1, i64 %12
  %14 = load i8, ptr %13, align 1, !tbaa !5
  %.not = icmp eq i8 %14, %11
  br i1 %.not, label %.critedge, label %15

15:                                               ; preds = %.lr.ph
  %gep = getelementptr i32, ptr %invariant.gep, i64 %12
  %16 = load i32, ptr %gep, align 4, !tbaa !8
  %17 = icmp sgt i32 %16, 0
  br i1 %17, label %.lr.ph, label %.critedge, !llvm.loop !10

.critedge:                                        ; preds = %.lr.ph, %15, %.preheader
  %.1.lcssa = phi i32 [ %.02330, %.preheader ], [ %16, %15 ], [ %.127, %.lr.ph ]
  %18 = sext i32 %.1.lcssa to i64
  %19 = getelementptr inbounds i8, ptr %1, i64 %18
  %20 = load i8, ptr %19, align 1, !tbaa !5
  %21 = icmp eq i8 %20, %11
  %22 = zext i1 %21 to i32
  %spec.select = add nsw i32 %.1.lcssa, %22
  %23 = icmp eq i32 %spec.select, %6
  br i1 %23, label %24, label %27

24:                                               ; preds = %.critedge
  %25 = trunc nuw nsw i64 %indvars.iv to i32
  %reass.sub = sub i32 %25, %6
  %26 = add i32 %reass.sub, 1
  br label %28

27:                                               ; preds = %.critedge
  %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 %.preheader, !llvm.loop !12

._crit_edge:                                      ; preds = %27, %2
  tail call void @free(ptr noundef %7) #4
  br label %28

28:                                               ; preds = %._crit_edge, %24
  %.024 = phi i32 [ %26, %24 ], [ -1, %._crit_edge ]
  ret i32 %.024
}

; Function Attrs: mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite)
declare void @free(ptr allocptr nocapture noundef) local_unnamed_addr #2

attributes #0 = { 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 = { mustprogress nofree nounwind willreturn memory(argmem: read) "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 = { mustprogress nounwind willreturn allockind("free") memory(argmem: readwrite, inaccessiblemem: readwrite) "alloc-family"="malloc" "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 willreturn memory(read) }
attributes #4 = { 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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C/C++ TBAA"}
!8 = !{!9, !9, i64 0}
!9 = !{!"int", !6, i64 0}
!10 = distinct !{!10, !11}
!11 = !{!"llvm.loop.mustprogress"}
!12 = distinct !{!12, !11}


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