1 #define _GNU_SOURCE 2 #include <float.h> 3 #include <math.h> 4 #include "libm.h" 5 6 #if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 7 long double exp10l(long double x) 8 { 9 return exp10(x); 10 } 11 #elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384 12 long double exp10l(long double x) 13 { 14 static const long double p10[] = { 15 1e-15L, 1e-14L, 1e-13L, 1e-12L, 1e-11L, 1e-10L, 16 1e-9L, 1e-8L, 1e-7L, 1e-6L, 1e-5L, 1e-4L, 1e-3L, 1e-2L, 1e-1L, 17 1, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 18 1e10, 1e11, 1e12, 1e13, 1e14, 1e15 19 }; 20 long double n, y = modfl(x, &n); 21 union ldshape u = {n}; 22 /* fabsl(n) < 16 without raising invalid on nan */ 23 if ((u.i.se & 0x7fff) < 0x3fff+4) { 24 if (!y) return p10[(int)n+15]; 25 y = exp2l(3.32192809488736234787031942948939L * y); 26 return y * p10[(int)n+15]; 27 } 28 return powl(10.0, x); 29 } 30 #endif 31 32 weak_alias(exp10l, pow10l); 33