use Inline C => Config =>
  BUILD_NOISY =>1,
  LD => 'g++ -static-libgcc',
  INC => '-IC:/MinGW/msys/1.0/local/include';

use Inline C => <<'EOC';

SV * foo(SV * x, SV * y) {
  return newSVnv(SvNV(x) * SvNV(y));
}

EOC

$x = foo(2.3, 1.1);
print $x, "\n";