; LLVM IR from steps3d/graphics-book :: Code/Core/stringUtils.ll/Z7getPathRKNSt7 (cxx1112basic_stringIcSt11char_traitsIcESaIcEEE)

; 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"

%"class.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }
%"class.std::allocator" = type { i8 }

@.str = external hidden unnamed_addr constant [1 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) #0 align 2

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

; Function Attrs: mustprogress uwtable
declare void @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6substrEmm(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef nonnull align 8 dereferenceable(32), i64 noundef, 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

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) #0 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress uwtable
define dso_local void @_Z7getPathRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull align 8 dereferenceable(32) %1) #2 personality ptr @__gxx_personality_v0 {
  %3 = alloca ptr, align 8
  %4 = alloca ptr, align 8
  %5 = alloca i32, align 4
  %6 = alloca i32, align 4
  %7 = alloca i8, align 1
  %8 = alloca %"class.std::allocator", align 1
  %9 = alloca ptr, align 8
  %10 = alloca i32, align 4
  store ptr %0, ptr %3, align 8
  store ptr %1, ptr %4, align 8, !tbaa !5
  call void @llvm.lifetime.start.p0(i64 4, ptr %5) #3
  %11 = load ptr, ptr %4, align 8, !tbaa !5
  %12 = call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %11) #3
  %13 = trunc i64 %12 to i32
  %14 = sub nsw i32 %13, 1
  store i32 %14, ptr %5, align 4, !tbaa !9
  br label %15

15:                                               ; preds = %45, %2
  %16 = load i32, ptr %5, align 4, !tbaa !9
  %17 = icmp sge i32 %16, 0
  br i1 %17, label %19, label %18

18:                                               ; preds = %15
  store i32 2, ptr %6, align 4
  br label %48

19:                                               ; preds = %15
  call void @llvm.lifetime.start.p0(i64 1, ptr %7) #3
  %20 = load ptr, ptr %4, align 8, !tbaa !5
  %21 = load i32, ptr %5, align 4, !tbaa !9
  %22 = sext i32 %21 to i64
  %23 = call noundef nonnull align 1 dereferenceable(1) ptr @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %20, i64 noundef %22) #3
  %24 = load i8, ptr %23, align 1, !tbaa !11
  store i8 %24, ptr %7, align 1, !tbaa !11
  %25 = load i8, ptr %7, align 1, !tbaa !11
  %26 = sext i8 %25 to i32
  %27 = icmp eq i32 %26, 92
  br i1 %27, label %36, label %28

28:                                               ; preds = %19
  %29 = load i8, ptr %7, align 1, !tbaa !11
  %30 = sext i8 %29 to i32
  %31 = icmp eq i32 %30, 47
  br i1 %31, label %36, label %32

32:                                               ; preds = %28
  %33 = load i8, ptr %7, align 1, !tbaa !11
  %34 = sext i8 %33 to i32
  %35 = icmp eq i32 %34, 58
  br i1 %35, label %36, label %41

36:                                               ; preds = %32, %28, %19
  %37 = load ptr, ptr %4, align 8, !tbaa !5
  %38 = load i32, ptr %5, align 4, !tbaa !9
  %39 = add nsw i32 %38, 1
  %40 = sext i32 %39 to i64
  call void @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6substrEmm(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull align 8 dereferenceable(32) %37, i64 noundef 0, i64 noundef %40)
  store i32 1, ptr %6, align 4
  br label %42

41:                                               ; preds = %32
  store i32 0, ptr %6, align 4
  br label %42

42:                                               ; preds = %41, %36
  call void @llvm.lifetime.end.p0(i64 1, ptr %7) #3
  %43 = load i32, ptr %6, align 4
  switch i32 %43, label %48 [
    i32 0, label %44
  ]

44:                                               ; preds = %42
  br label %45

45:                                               ; preds = %44
  %46 = load i32, ptr %5, align 4, !tbaa !9
  %47 = add nsw i32 %46, -1
  store i32 %47, ptr %5, align 4, !tbaa !9
  br label %15, !llvm.loop !12

48:                                               ; preds = %42, %18
  call void @llvm.lifetime.end.p0(i64 4, ptr %5) #3
  %49 = load i32, ptr %6, align 4
  switch i32 %49, label %62 [
    i32 2, label %50
    i32 1, label %56
  ]

50:                                               ; preds = %48
  call void @llvm.lifetime.start.p0(i64 1, ptr %8) #3
  call void @_ZNSaIcEC2Ev(ptr noundef nonnull align 1 dereferenceable(1) %8) #3
  invoke void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2IS3_EEPKcRKS3_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef @.str, ptr noundef nonnull align 1 dereferenceable(1) %8)
          to label %51 unwind label %52

51:                                               ; preds = %50
  call void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1) %8) #3
  call void @llvm.lifetime.end.p0(i64 1, ptr %8) #3
  br label %56

52:                                               ; preds = %50
  %53 = landingpad { ptr, i32 }
          cleanup
  %54 = extractvalue { ptr, i32 } %53, 0
  store ptr %54, ptr %9, align 8
  %55 = extractvalue { ptr, i32 } %53, 1
  store i32 %55, ptr %10, align 4
  call void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1) %8) #3
  call void @llvm.lifetime.end.p0(i64 1, ptr %8) #3
  br label %57

56:                                               ; preds = %51, %48
  ret void

57:                                               ; preds = %52
  %58 = load ptr, ptr %9, align 8
  %59 = load i32, ptr %10, align 4
  %60 = insertvalue { ptr, i32 } poison, ptr %58, 0
  %61 = insertvalue { ptr, i32 } %60, i32 %59, 1
  resume { ptr, i32 } %61

62:                                               ; preds = %48
  unreachable
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSaIcEC2Ev(ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2IS3_EEPKcRKS3_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef, ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #0 align 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 = { nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #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 = !{!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"

%"class.std::__cxx11::basic_string" = type { %"struct.std::__cxx11::basic_string<char>::_Alloc_hider", i64, %union.anon }
%"struct.std::__cxx11::basic_string<char>::_Alloc_hider" = type { ptr }
%union.anon = type { i64, [8 x i8] }
%"class.std::allocator" = type { i8 }

@.str = external hidden unnamed_addr constant [1 x i8], align 1

; Function Attrs: mustprogress nounwind uwtable
declare noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32)) local_unnamed_addr #0 align 2

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

; Function Attrs: mustprogress uwtable
declare void @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6substrEmm(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8, ptr noundef nonnull align 8 dereferenceable(32), i64 noundef, i64 noundef) local_unnamed_addr #2 align 2

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

; Function Attrs: mustprogress nounwind uwtable
declare noundef nonnull align 1 dereferenceable(1) ptr @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32), i64 noundef) local_unnamed_addr #0 align 2

declare i32 @__gxx_personality_v0(...)

; Function Attrs: mustprogress uwtable
define dso_local void @_Z7getPathRKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE(ptr dead_on_unwind noalias writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull align 8 dereferenceable(32) %1) local_unnamed_addr #2 personality ptr @__gxx_personality_v0 {
  %3 = alloca %"class.std::allocator", align 1
  %4 = tail call noundef i64 @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6lengthEv(ptr noundef nonnull align 8 dereferenceable(32) %1) #3
  %5 = trunc i64 %4 to i32
  %6 = icmp sgt i32 %5, 0
  br i1 %6, label %.lr.ph.preheader, label %._crit_edge

.lr.ph.preheader:                                 ; preds = %2
  %7 = and i64 %4, 2147483647
  br label %.lr.ph

.lr.ph:                                           ; preds = %.lr.ph.preheader, %.backedge
  %indvars.iv = phi i64 [ %7, %.lr.ph.preheader ], [ %indvars.iv.next, %.backedge ]
  %indvars.iv.next = add nsw i64 %indvars.iv, -1
  %8 = tail call noundef nonnull align 1 dereferenceable(1) ptr @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEixEm(ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef %indvars.iv.next) #3
  %9 = load i8, ptr %8, align 1, !tbaa !5
  switch i8 %9, label %.backedge [
    i8 92, label %10
    i8 58, label %10
    i8 47, label %10
  ]

10:                                               ; preds = %.lr.ph, %.lr.ph, %.lr.ph
  tail call void @_ZNKSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEE6substrEmm(ptr dead_on_unwind writable sret(%"class.std::__cxx11::basic_string") align 8 %0, ptr noundef nonnull align 8 dereferenceable(32) %1, i64 noundef 0, i64 noundef %indvars.iv)
  switch i8 %9, label %.backedge [
    i8 92, label %.thread25
    i8 58, label %.thread25
    i8 47, label %.thread25
  ]

.backedge:                                        ; preds = %10, %.lr.ph
  %11 = icmp ugt i64 %indvars.iv, 1
  br i1 %11, label %.lr.ph, label %._crit_edge, !llvm.loop !8

._crit_edge:                                      ; preds = %.backedge, %2
  call void @llvm.lifetime.start.p0(i64 1, ptr nonnull %3) #3
  call void @_ZNSaIcEC2Ev(ptr noundef nonnull align 1 dereferenceable(1) %3) #3
  invoke void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2IS3_EEPKcRKS3_(ptr noundef nonnull align 8 dereferenceable(32) %0, ptr noundef nonnull @.str, ptr noundef nonnull align 1 dereferenceable(1) %3)
          to label %12 unwind label %13

12:                                               ; preds = %._crit_edge
  call void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1) %3) #3
  call void @llvm.lifetime.end.p0(i64 1, ptr nonnull %3) #3
  br label %.thread25

13:                                               ; preds = %._crit_edge
  %14 = landingpad { ptr, i32 }
          cleanup
  call void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1) %3) #3
  call void @llvm.lifetime.end.p0(i64 1, ptr nonnull %3) #3
  resume { ptr, i32 } %14

.thread25:                                        ; preds = %10, %10, %10, %12
  ret void
}

; Function Attrs: mustprogress nounwind uwtable
declare void @_ZNSaIcEC2Ev(ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #0 align 2

; Function Attrs: mustprogress uwtable
declare dso_local void @_ZNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEC2IS3_EEPKcRKS3_(ptr noundef nonnull align 8 dereferenceable(32), ptr noundef, ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #2 align 2

; Function Attrs: mustprogress nounwind uwtable
declare dso_local void @_ZNSt15__new_allocatorIcED2Ev(ptr noundef nonnull align 1 dereferenceable(1)) unnamed_addr #0 align 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 = { mustprogress nocallback nofree nosync nounwind willreturn memory(argmem: readwrite) }
attributes #2 = { 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 #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 = !{!"omnipotent char", !7, i64 0}
!7 = !{!"Simple C++ TBAA"}
!8 = distinct !{!8, !9}
!9 = !{!"llvm.loop.mustprogress"}


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