1 2#include <machine/asm.h> 3#include <i386-math-asm.h> 4#include <libm-alias-finite.h> 5 6DEFINE_DBL_MIN 7 8#ifdef PIC 9# define MO(op) op##@GOTOFF(%ecx) 10#else 11# define MO(op) op 12#endif 13 14 .text 15/* 10^x = 2^(x * log2(10)) */ 16ENTRY(__ieee754_exp10) 17#ifdef PIC 18 LOAD_PIC_REG (cx) 19#endif 20 fldl 4(%esp) 21/* I added the following ugly construct because exp(+-Inf) resulted 22 in NaN. The ugliness results from the bright minds at Intel. 23 For the i686 the code can be written better. 24 -- drepper@cygnus.com. */ 25 fxam /* Is NaN or +-Inf? */ 26 fstsw %ax 27 movb $0x45, %dh 28 andb %ah, %dh 29 cmpb $0x05, %dh 30 je 1f /* Is +-Inf, jump. */ 31 fldl2t 32 fmulp /* x * log2(10) */ 33 fld %st 34 frndint /* int(x * log2(10)) */ 35 fsubr %st,%st(1) /* fract(x * log2(10)) */ 36 fxch 37 f2xm1 /* 2^(fract(x * log2(10))) - 1 */ 38 fld1 39 faddp /* 2^(fract(x * log2(10))) */ 40 fscale /* e^x */ 41 fstp %st(1) 42 DBL_NARROW_EVAL_UFLOW_NONNEG_NAN 43 ret 44 451: testl $0x200, %eax /* Test sign. */ 46 jz 2f /* If positive, jump. */ 47 fstp %st 48 fldz /* Set result to 0. */ 492: ret 50END (__ieee754_exp10) 51libm_alias_finite (__ieee754_exp10, __exp10) 52