ubuntu-buildroot/output/build/glibc-2.36-81-g4f4d7a13edfd.../sysdeps/i386/fpu/e_exp10.S

52 lines
1.1 KiB
ArmAsm
Raw Permalink Normal View History

2024-04-01 15:19:46 +00:00
#include <machine/asm.h>
#include <i386-math-asm.h>
#include <libm-alias-finite.h>
DEFINE_DBL_MIN
#ifdef PIC
# define MO(op) op##@GOTOFF(%ecx)
#else
# define MO(op) op
#endif
.text
/* 10^x = 2^(x * log2(10)) */
ENTRY(__ieee754_exp10)
#ifdef PIC
LOAD_PIC_REG (cx)
#endif
fldl 4(%esp)
/* I added the following ugly construct because exp(+-Inf) resulted
in NaN. The ugliness results from the bright minds at Intel.
For the i686 the code can be written better.
-- drepper@cygnus.com. */
fxam /* Is NaN or +-Inf? */
fstsw %ax
movb $0x45, %dh
andb %ah, %dh
cmpb $0x05, %dh
je 1f /* Is +-Inf, jump. */
fldl2t
fmulp /* x * log2(10) */
fld %st
frndint /* int(x * log2(10)) */
fsubr %st,%st(1) /* fract(x * log2(10)) */
fxch
f2xm1 /* 2^(fract(x * log2(10))) - 1 */
fld1
faddp /* 2^(fract(x * log2(10))) */
fscale /* e^x */
fstp %st(1)
DBL_NARROW_EVAL_UFLOW_NONNEG_NAN
ret
1: testl $0x200, %eax /* Test sign. */
jz 2f /* If positive, jump. */
fstp %st
fldz /* Set result to 0. */
2: ret
END (__ieee754_exp10)
libm_alias_finite (__ieee754_exp10, __exp10)