; LLVM IR from UtkarshPathrabe/Competitive-Coding :: Cracking the Coding Interview/Chapter 01/Question04.ll (Z7isEqualPcS_)

; 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 zeroext i1 @_Z7isEqualPcS_(ptr noundef %0, ptr noundef %1) #0 {
  %3 = alloca i1, align 1
  %4 = alloca ptr, align 8
  %5 = alloca ptr, align 8
  %6 = alloca i32, align 4
  %7 = alloca i32, align 4
  store ptr %0, ptr %4, align 8, !tbaa !5
  store ptr %1, ptr %5, align 8, !tbaa !5
  %8 = load ptr, ptr %4, align 8, !tbaa !5
  %9 = call i64 @strlen(ptr noundef %8) #3
  %10 = load ptr, ptr %5, align 8, !tbaa !5
  %11 = call i64 @strlen(ptr noundef %10) #3
  %12 = icmp ne i64 %9, %11
  br i1 %12, label %13, label %14

13:                                               ; preds = %2
  store i1 false, ptr %3, align 1
  br label %44

14:                                               ; preds = %2
  call void @llvm.lifetime.start.p0(i64 4, ptr %6) #4
  store i32 0, ptr %6, align 4, !tbaa !9
  br label %15

15:                                               ; preds = %38, %14
  %16 = load i32, ptr %6, align 4, !tbaa !9
  %17 = sext i32 %16 to i64
  %18 = load ptr, ptr %4, align 8, !tbaa !5
  %19 = call i64 @strlen(ptr noundef %18) #3
  %20 = icmp ult i64 %17, %19
  br i1 %20, label %22, label %21

21:                                               ; preds = %15
  store i32 2, ptr %7, align 4
  br label %41

22:                                               ; preds = %15
  %23 = load ptr, ptr %4, align 8, !tbaa !5
  %24 = load i32, ptr %6, align 4, !tbaa !9
  %25 = sext i32 %24 to i64
  %26 = getelementptr inbounds i8, ptr %23, i64 %25
  %27 = load i8, ptr %26, align 1, !tbaa !11
  %28 = sext i8 %27 to i32
  %29 = load ptr, ptr %5, align 8, !tbaa !5
  %30 = load i32, ptr %6, 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 = icmp ne i32 %28, %34
  br i1 %35, label %36, label %37

36:                                               ; preds = %22
  store i1 false, ptr %3, align 1
  store i32 1, ptr %7, align 4
  br label %41

37:                                               ; preds = %22
  br label %38

38:                                               ; preds = %37
  %39 = load i32, ptr %6, align 4, !tbaa !9
  %40 = add nsw i32 %39, 1
  store i32 %40, ptr %6, align 4, !tbaa !9
  br label %15, !llvm.loop !12

41:                                               ; preds = %36, %21
  call void @llvm.lifetime.end.p0(i64 4, ptr %6) #4
  %42 = load i32, ptr %7, align 4
  switch i32 %42, label %46 [
    i32 2, label %43
    i32 1, label %44
  ]

43:                                               ; preds = %41
  store i1 true, ptr %3, align 1
  br label %44

44:                                               ; preds = %43, %41, %13
  %45 = load i1, ptr %3, align 1
  ret i1 %45

46:                                               ; preds = %41
  unreachable
}

; Function Attrs: nounwind willreturn memory(read)
declare i64 @strlen(ptr noundef) #1

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.start.p0(i64 immarg, ptr nocapture) #2

; Function Attrs: nocallback nofree nosync nounwind willreturn memory(argmem: readwrite)
declare void @llvm.lifetime.end.p0(i64 immarg, ptr nocapture) #2

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 = { 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 #2 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
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 = !{!"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 = !{!7, !7, i64 0}
!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"

; Function Attrs: mustprogress nofree nounwind willreturn memory(argmem: read) uwtable
define dso_local noundef zeroext i1 @_Z7isEqualPcS_(ptr nocapture noundef readonly %0, ptr nocapture noundef readonly %1) local_unnamed_addr #0 {
  %3 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %0) #2
  %4 = tail call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) #2
  %.not = icmp eq i64 %3, %4
  br i1 %.not, label %.preheader, label %.loopexit

.preheader:                                       ; preds = %2
  %5 = icmp eq i64 %3, 0
  br i1 %5, label %.loopexit, label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph, %.preheader
  %indvars.iv = phi i64 [ 0, %.preheader ], [ %indvars.iv.next, %.lr.ph ]
  %6 = getelementptr inbounds i8, ptr %0, i64 %indvars.iv
  %7 = load i8, ptr %6, align 1, !tbaa !5
  %8 = getelementptr inbounds i8, ptr %1, i64 %indvars.iv
  %9 = load i8, ptr %8, align 1, !tbaa !5
  %.not13 = icmp eq i8 %7, %9
  %.not13.not = xor i1 %.not13, true
  %indvars.iv.next = add nuw i64 %indvars.iv, 1
  %exitcond = icmp eq i64 %indvars.iv.next, %3
  %or.cond = select i1 %.not13.not, i1 true, i1 %exitcond
  br i1 %or.cond, label %.loopexit, label %.lr.ph, !llvm.loop !8

.loopexit:                                        ; preds = %.lr.ph, %.preheader, %2
  %.1 = phi i1 [ false, %2 ], [ true, %.preheader ], [ %.not13, %.lr.ph ]
  ret i1 %.1
}

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

attributes #0 = { mustprogress nofree nounwind willreturn memory(argmem: read) 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 = { 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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


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