projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| ee188d55 RM |
1 | /* |
| 2 | * Written by J.T. Conklin <jtc@netbsd.org>. | |
| 3 | * Public domain. | |
| 4 | * | |
| 5 | * Adapted for `long double' by Ulrich Drepper <drepper@cygnus.com>. | |
| 6 | */ | |
| 7 | ||
| 8 | #include <machine/asm.h> | |
| 9 | ||
| 10 | RCSID("$NetBSD: $") | |
| 11 | ||
| 12 | /* e^x = 2^(x * log2l(e)) */ | |
| 13 | ENTRY(__ieee754_expl) | |
| 14 | fldt 4(%esp) | |
| 15 | /* I added the following ugly construct because expl(+-Inf) resulted | |
| 16 | in NaN. The ugliness results from the bright minds at Intel. | |
| cccda09f | 17 | For the i686 the code can be written better. |
| ee188d55 RM |
18 | -- drepper@cygnus.com. */ |
| 19 | fxam /* Is NaN or +-Inf? */ | |
| 20 | fstsw %ax | |
| 21 | sahf | |
| 22 | jnc .LnoInfNaN /* No, jump. */ | |
| 23 | jp .LisInf /* Is +-Inf, jump. */ | |
| 24 | .LnoInfNaN: | |
| 25 | fldl2e | |
| 26 | fmulp /* x * log2(e) */ | |
| 27 | fstl %st(1) | |
| 28 | frndint /* int(x * log2(e)) */ | |
| 29 | fstl %st(2) | |
| 30 | fsubrp /* fract(x * log2(e)) */ | |
| 31 | f2xm1 /* 2^(fract(x * log2(e))) - 1 */ | |
| 32 | fld1 | |
| 33 | faddp /* 2^(fract(x * log2(e))) */ | |
| 34 | fscale /* e^x */ | |
| 35 | ret | |
| 36 | ||
| 37 | .LisInf: | |
| 38 | andb $2, %ah /* Test sign. */ | |
| 39 | jz .LpInf /* If positive, jump. */ | |
| 40 | fldz /* Set result to 0. */ | |
| 41 | .LpInf: ret | |
| cccda09f | 42 | PSEUDO_END (__ieee754_expl) |