standard std::min/max use crefs for passing arguments.
such behaviour isn't optimal for primitive types.
so called call_traits ( vide boost ) could improve std::
algorithms.
e.g.:
#include <algorithm>
#include <boost/call_traits.hpp>
long foo( long x, long y )
{
return std::max( x, y );
}
template < typename T >
typename boost::call_traits< T >::param_type boosted_max(
typename boost::call_traits< T >::param_type x,
typename boost::call_traits< T >::param_type y )
{
return ( x > y ? x : y );
}
long bar( long x, long y )
{
return boosted_max< long >( x, y );
}
foo(long, long):
leaq -16(%rsp), %rax #, tmp63
leaq -8(%rsp), %rdx #, tmp64
cmpq %rsi, %rdi # y,
movq %rdi, -8(%rsp) # x, x
movq %rsi, -16(%rsp) # y, y
cmovge %rdx, %rax # tmp64,, tmp63
movq (%rax), %rax #, tmp62
ret
bar(long, long):
cmpq %rdi, %rsi # x, y
cmovge %rsi, %rdi # y,, x
movq %rdi, %rax # x, <result>
ret
are there any plans of implementing call_traits in std::(trX) ?
--
Summary: unoptimal std::min/max (missed call_traits).
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: libstdc++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: pluto at agmk dot net
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30261
