1 struct ieee754_double { 2 double d; 3 }; 4 extern const float __exp_deltatable[178]; __ieee754_expf(float x)5float __ieee754_expf (float x) 6 { 7 static const float himark = 88.72283935546875; 8 static const float lomark = -103.972084045410; 9 if (__builtin_isless(x, himark) && __builtin_isgreater(x, lomark)) 10 { 11 int tval; 12 double x22, t, result, dx; 13 float delta; 14 struct ieee754_double ex2_u; 15 dx -= t; 16 tval = (int) (t * 512.0); 17 if (t >= 0) 18 delta = - __exp_deltatable[tval]; 19 else 20 delta = __exp_deltatable[-tval]; 21 x22 = (0.5000000496709180453 * dx + 1.0000001192102037084) * dx + delta; 22 result = x22 * ex2_u.d + ex2_u.d; 23 return (float) result; 24 } 25 return x; 26 } 27