libstdc++ change breaks simple code

[Mixtim <mixtim at home dot com>]

Here is the code in question:

#include <cmath>

using namespace std;

int
main()
{
   double d = sqrt(1.0);
   return 0;
}

gcc version 3.0 20010520 (prerelease) compiles this fine.

gcc version 3.0 20010525 (prerelease) barfs.
mixtim@cg392862-a ~/work> g++ test.cc       
test.cc: In function `int main()':
test.cc:8: call of overloaded `__glibcpp_sqrt(double)' is ambiguous
/home/mixtim/gcc/lib/gcc-lib/i386-unknown-freebsd4.3/3.0/include/math.h:135: candidates
   are: double __glibcpp_sqrt(double)
/home/mixtim/gcc/include/g++-v3/bits/std_cmath.h:528:                 long 
   double std::__glibcpp_sqrt(long double)
/home/mixtim/gcc/include/g++-v3/bits/std_cmath.h:524:                 double 
   std::__glibcpp_sqrt(double)
/home/mixtim/gcc/include/g++-v3/bits/std_cmath.h:520:                 float 
   std::__glibcpp_sqrt(float)

gcc version 3.0 20010520 has the following defs for sqrt:

#if _GLIBCPP_HAVE___BUILTIN_SQRTF
  inline float 
  sqrt(float __x) { return __builtin_sqrtf(__x); }
#elif _GLIBCPP_HAVE_SQRTF
  inline float 
  sqrt(float __x) { return ::sqrtf(__x); }
#else
  inline float 
  sqrt(float __x) { return ::sqrt(static_cast<double>(__x)); }
#endif

while gcc version 3.0 20010525 has the following:

  // sqrt.
  inline float
  sqrt(float __x)
  { return __builtin_sqrtf(__x); }
	
  inline double
  sqrt(double __x)
  { return __builtin_fsqrt(__x); }
	      
  inline long double
  sqrt(long double __x)
  { return __builtin_sqrtl(__x); }

Why was this done?