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[libc++] Refactor num_get optimization to not be ABI breaking #121690

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Merged
merged 1 commit into from
Jan 30, 2025
Merged

[libc++] Refactor num_get optimization to not be ABI breaking #121690

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2 changes: 0 additions & 2 deletions libcxx/include/__configuration/abi.h
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Original file line number Diff line number Diff line change
Expand Up @@ -57,8 +57,6 @@
// because it changes the mangling of the virtual function located in the vtable, which
// changes how it gets signed.
# define _LIBCPP_ABI_BAD_FUNCTION_CALL_GOOD_WHAT_MESSAGE
// Enable optimized version of __do_get_(un)signed which avoids redundant copies.
# define _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
// Give reverse_iterator<T> one data member of type T, not two.
// Also, in C++17 and later, don't derive iterator types from std::iterator.
# define _LIBCPP_ABI_NO_ITERATOR_BASES
Expand Down
97 changes: 42 additions & 55 deletions libcxx/include/locale
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Original file line number Diff line number Diff line change
Expand Up @@ -400,8 +400,9 @@ struct __num_get : protected __num_get_base {
unsigned*& __g_end,
unsigned& __dc,
_CharT* __atoms);
# ifndef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
static string __stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep);

[[__deprecated__("This exists only for ABI compatibility")]] static string
__stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep);
static int __stage2_int_loop(
_CharT __ct,
int __base,
Expand All @@ -414,55 +415,32 @@ struct __num_get : protected __num_get_base {
unsigned*& __g_end,
_CharT* __atoms);

# else
static string __stage2_int_prep(ios_base& __iob, _CharT& __thousands_sep) {
_LIBCPP_HIDE_FROM_ABI static string __stage2_int_prep(ios_base& __iob, _CharT& __thousands_sep) {
locale __loc = __iob.getloc();
const numpunct<_CharT>& __np = use_facet<numpunct<_CharT> >(__loc);
__thousands_sep = __np.thousands_sep();
return __np.grouping();
}

const _CharT* __do_widen(ios_base& __iob, _CharT* __atoms) const { return __do_widen_p(__iob, __atoms); }

static int __stage2_int_loop(
_CharT __ct,
int __base,
char* __a,
char*& __a_end,
unsigned& __dc,
_CharT __thousands_sep,
const string& __grouping,
unsigned* __g,
unsigned*& __g_end,
const _CharT* __atoms);
_LIBCPP_HIDE_FROM_ABI const _CharT* __do_widen(ios_base& __iob, _CharT* __atoms) const {
return __do_widen_p(__iob, __atoms);
}

private:
template <typename _Tp>
const _Tp* __do_widen_p(ios_base& __iob, _Tp* __atoms) const {
_LIBCPP_HIDE_FROM_ABI const _Tp* __do_widen_p(ios_base& __iob, _Tp* __atoms) const {
locale __loc = __iob.getloc();
use_facet<ctype<_Tp> >(__loc).widen(__src, __src + __int_chr_cnt, __atoms);
return __atoms;
}

const char* __do_widen_p(ios_base& __iob, char* __atoms) const {
_LIBCPP_HIDE_FROM_ABI const char* __do_widen_p(ios_base& __iob, char* __atoms) const {
(void)__iob;
(void)__atoms;
return __src;
}
# endif
};

# ifndef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
template <class _CharT>
string __num_get<_CharT>::__stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep) {
locale __loc = __iob.getloc();
std::use_facet<ctype<_CharT> >(__loc).widen(__src, __src + __int_chr_cnt, __atoms);
const numpunct<_CharT>& __np = std::use_facet<numpunct<_CharT> >(__loc);
__thousands_sep = __np.thousands_sep();
return __np.grouping();
}
# endif

template <class _CharT>
string __num_get<_CharT>::__stage2_float_prep(
ios_base& __iob, _CharT* __atoms, _CharT& __decimal_point, _CharT& __thousands_sep) {
Expand All @@ -475,18 +453,17 @@ string __num_get<_CharT>::__stage2_float_prep(
}

template <class _CharT>
int
# ifndef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
__num_get<_CharT>::__stage2_int_loop(_CharT __ct, int __base, char* __a, char*& __a_end,
unsigned& __dc, _CharT __thousands_sep, const string& __grouping,
unsigned* __g, unsigned*& __g_end, _CharT* __atoms)
# else
__num_get<_CharT>::__stage2_int_loop(_CharT __ct, int __base, char* __a, char*& __a_end,
unsigned& __dc, _CharT __thousands_sep, const string& __grouping,
unsigned* __g, unsigned*& __g_end, const _CharT* __atoms)

# endif
{
int __num_get<_CharT>::__stage2_int_loop(
_CharT __ct,
int __base,
char* __a,
char*& __a_end,
unsigned& __dc,
_CharT __thousands_sep,
const string& __grouping,
unsigned* __g,
unsigned*& __g_end,
_CharT* __atoms) {
if (__a_end == __a && (__ct == __atoms[24] || __ct == __atoms[25])) {
*__a_end++ = __ct == __atoms[24] ? '+' : '-';
__dc = 0;
Expand Down Expand Up @@ -856,14 +833,9 @@ _InputIterator num_get<_CharT, _InputIterator>::__do_get_signed(
// Stage 2
char_type __thousands_sep;
const int __atoms_size = __num_get_base::__int_chr_cnt;
# ifdef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
char_type __atoms1[__atoms_size];
const char_type* __atoms = this->__do_widen(__iob, __atoms1);
string __grouping = this->__stage2_int_prep(__iob, __thousands_sep);
# else
char_type __atoms[__atoms_size];
string __grouping = this->__stage2_int_prep(__iob, __atoms, __thousands_sep);
# endif
string __buf;
__buf.resize(__buf.capacity());
char* __a = &__buf[0];
Expand All @@ -879,7 +851,17 @@ _InputIterator num_get<_CharT, _InputIterator>::__do_get_signed(
__a = &__buf[0];
__a_end = __a + __tmp;
}
if (this->__stage2_int_loop(*__b, __base, __a, __a_end, __dc, __thousands_sep, __grouping, __g, __g_end, __atoms))
if (this->__stage2_int_loop(
*__b,
__base,
__a,
__a_end,
__dc,
__thousands_sep,
__grouping,
__g,
__g_end,
const_cast<char_type*>(__atoms)))
break;
}
if (__grouping.size() != 0 && __g_end - __g < __num_get_base::__num_get_buf_sz)
Expand All @@ -905,14 +887,9 @@ _InputIterator num_get<_CharT, _InputIterator>::__do_get_unsigned(
// Stage 2
char_type __thousands_sep;
const int __atoms_size = __num_get_base::__int_chr_cnt;
# ifdef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
char_type __atoms1[__atoms_size];
const char_type* __atoms = this->__do_widen(__iob, __atoms1);
string __grouping = this->__stage2_int_prep(__iob, __thousands_sep);
# else
char_type __atoms[__atoms_size];
string __grouping = this->__stage2_int_prep(__iob, __atoms, __thousands_sep);
# endif
string __buf;
__buf.resize(__buf.capacity());
char* __a = &__buf[0];
Expand All @@ -928,7 +905,17 @@ _InputIterator num_get<_CharT, _InputIterator>::__do_get_unsigned(
__a = &__buf[0];
__a_end = __a + __tmp;
}
if (this->__stage2_int_loop(*__b, __base, __a, __a_end, __dc, __thousands_sep, __grouping, __g, __g_end, __atoms))
if (this->__stage2_int_loop(
*__b,
__base,
__a,
__a_end,
__dc,
__thousands_sep,
__grouping,
__g,
__g_end,
const_cast<char_type*>(__atoms)))
break;
}
if (__grouping.size() != 0 && __g_end - __g < __num_get_base::__num_get_buf_sz)
Expand Down
10 changes: 10 additions & 0 deletions libcxx/src/locale.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5650,6 +5650,16 @@ void moneypunct_byname<wchar_t, true>::init(const char* nm) {

void __do_nothing(void*) {}

// Legacy ABI __num_get functions - the new ones are _LIBCPP_HIDE_FROM_ABI
template <class _CharT>
string __num_get<_CharT>::__stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep) {
locale __loc = __iob.getloc();
std::use_facet<ctype<_CharT> >(__loc).widen(__src, __src + __int_chr_cnt, __atoms);
const numpunct<_CharT>& __np = std::use_facet<numpunct<_CharT> >(__loc);
__thousands_sep = __np.thousands_sep();
return __np.grouping();
}

template class _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS collate<char>;
_LIBCPP_IF_WIDE_CHARACTERS(template class _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS collate<wchar_t>;)

Expand Down