realAscot/kicad-source
1
0
Fork 0
mirror of https://gitlab.com/kicad/code/kicad.git synced 2025-09-13 17:53:11 +02:00
Code Issues Packages Projects Releases Wiki Activity

Add fast_float for float parsing.

Browse Source 
2x faster than both std::from_chars and strtod on Windows.

macOS will get to benefit from a modern from_chars impl too.
This commit is contained in:
Mark Roszko 2025-08-29 21:32:15 -04:00
parent 8acf5c1a25
commit b3de964eff
4 changed files with 31 additions and 63 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
common/CMakeLists.txt
View File

@ -269,6 +269,7 @@ target_link_libraries( kicommon
kiplatform
nlohmann_json
nlohmann_json_schema_validator
FastFloat::fast_float
fmt::fmt
CURL::libcurl
picosha2

41
common/dsnlexer.cpp
View File

@ -22,7 +22,7 @@
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <charconv>
#include <fast_float/fast_float.h>
#include <cstdarg>
#include <cstdio>
#include <cstdlib> // bsearch()
@ -861,43 +861,13 @@ wxArrayString* DSNLEXER::ReadCommentLines()
double DSNLEXER::parseDouble()
{
// We try here to be locale independent to avoid the need to switch to a "C" locale
#if ( defined( __GNUC__ ) && __GNUC__ < 11 ) || ( defined( __clang__ ) && __clang_major__ < 13 )
// GCC older than 11 "supports" C++17 without supporting the C++17 std::from_chars for doubles
// clang is similar
// Use wxString::ToCDouble() which is designed to be locale independent
wxString tmp = CurStr();
double fval;
bool success = tmp.ToCDouble( &fval );
if( !success )
{
wxString error;
error.Printf( _( "Invalid floating point number in\nfile: '%s'\nline: %d\noffset: %d" ),
CurSource(), CurLineNumber(), CurOffset() );
THROW_IO_ERROR( error );
}
return fval;
#else
// Use std::from_chars which is designed to be locale independent and performance oriented
// for data interchange
// Use fast_float::from_chars which is designed to be locale independent and significantly
// faster than strtod and std::from_chars
const std::string& str = CurStr();
// Offset any leading whitespace, this is one thing from_chars does not handle
size_t woff = 0;
while( std::isspace( str[woff] ) && woff < str.length() )
{
woff++;
}
double dval{};
std::from_chars_result res =
std::from_chars( str.data() + woff, str.data() + str.size(), dval );
fast_float::from_chars_result res = fast_float::from_chars( str.data(), str.data() + str.size(), dval,
fast_float::chars_format::skip_white_space );
if( res.ec != std::errc() )
{
@ -906,5 +876,4 @@ double DSNLEXER::parseDouble()
}
return dval;
#endif
}

50
eeschema/sim/sim_value.cpp
View File

@ -22,7 +22,7 @@
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <charconv>
#include <fast_float/fast_float.h>
#include <sim/sim_value.h>
#include <wx/translation.h>
#include <ki_exception.h>
@ -382,22 +382,20 @@ std::string SIM_VALUE::ConvertNotation( const std::string& aString, NOTATION aFr
int exponent = parseResult.exponent ? *parseResult.exponent : 0;
exponent += parseResult.unitPrefixExponent ? *parseResult.unitPrefixExponent : 0;
try
{
int expReduction = 0;
std::string prefix = SIM_VALUE_PARSER::ExponentToUnitPrefix( exponent, expReduction,
aToNotation );
double significand{};
wxString( parseResult.significand ).ToCDouble( &significand );
int expReduction = 0;
std::string prefix = SIM_VALUE_PARSER::ExponentToUnitPrefix( exponent, expReduction,
aToNotation );
double significand{};
exponent -= expReduction;
return fmt::format( "{:g}{}", significand * std::pow( 10, exponent ),
prefix );
}
catch( const std::invalid_argument& )
{
// best efforts
}
fast_float::from_chars(
parseResult.significand.data(),
parseResult.significand.data() + parseResult.significand.size(),
significand,
fast_float::chars_format::skip_white_space | fast_float::chars_format::allow_leading_plus );
exponent -= expReduction;
return fmt::format( "{:g}{}", significand * std::pow( 10, exponent ),
prefix );
}
return aString;
@ -446,19 +444,17 @@ double SIM_VALUE::ToDouble( const std::string& aString, double aDefault )
if( parseResult.isOk && !parseResult.isEmpty && !parseResult.significand.empty() )
{
try
{
LOCALE_IO toggle;
int exponent = parseResult.exponent ? *parseResult.exponent : 0;
int exponent = parseResult.exponent ? *parseResult.exponent : 0;
exponent += parseResult.unitPrefixExponent ? *parseResult.unitPrefixExponent : 0;
exponent += parseResult.unitPrefixExponent ? *parseResult.unitPrefixExponent : 0;
double significand{};
return std::stod( parseResult.significand ) * std::pow( 10, exponent );
}
catch( const std::invalid_argument& )
{
// best efforts
}
fast_float::from_chars( parseResult.significand.data(),
parseResult.significand.data() + parseResult.significand.size(),
significand,
fast_float::chars_format::skip_white_space | fast_float::chars_format::allow_leading_plus );
return significand * std::pow( 10, exponent );
}
return aDefault;

2
thirdparty/CMakeLists.txt vendored
View File

@ -48,6 +48,8 @@ add_subdirectory( delaunator )
add_subdirectory( dxflib_qcad )
add_subdirectory( dynamic_bitset )
add_subdirectory( expected )
set( FASTFLOAT_INSTALL OFF )
add_subdirectory( fast_float )
set( FMT_INSTALL OFF )
add_subdirectory( fmt )
add_subdirectory( gzip-hpp )