projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| c9cf6dde AJ |
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 | * Adapted for x86-64 by Andreas Jaeger <aj@suse.de>. | |
| 7 | */ | |
| 8 | ||
| 9 | #include <machine/asm.h> | |
| 10 | ||
| 11 | RCSID("$NetBSD: $") | |
| 12 | ||
| 13 | ||
| 14 | #ifdef __ELF__ | |
| 15 | .section .rodata | |
| 16 | #else | |
| 17 | .text | |
| 18 | #endif | |
| 19 | .align ALIGNARG(4) | |
| 20 | ASM_TYPE_DIRECTIVE(one,@object) | |
| 21 | one: .double 1.0 | |
| 22 | ASM_SIZE_DIRECTIVE(one) | |
| 23 | /* It is not important that this constant is precise. It is only | |
| 24 | a value which is known to be on the safe side for using the | |
| 25 | fyl2xp1 instruction. */ | |
| 26 | ASM_TYPE_DIRECTIVE(limit,@object) | |
| 27 | limit: .double 0.29 | |
| 28 | ASM_SIZE_DIRECTIVE(limit) | |
| 29 | ||
| 30 | ||
| 31 | #ifdef PIC | |
| 32 | #define MO(op) op##(%rip) | |
| 33 | #else | |
| 34 | #define MO(op) op | |
| 35 | #endif | |
| 36 | ||
| 37 | .text | |
| 38 | ENTRY(__ieee754_logl) | |
| 39 | fldln2 // log(2) | |
| 40 | fldt 8(%rsp) // x : log(2) | |
| 41 | fld %st // x : x : log(2) | |
| 11bf311e | 42 | fsubl MO(one) // x-1 : x : log(2) |
| c9cf6dde AJ |
43 | fld %st // x-1 : x-1 : x : log(2) |
| 44 | fabs // |x-1| : x-1 : x : log(2) | |
| 45 | fcompl MO(limit) // x-1 : x : log(2) | |
| 46 | fnstsw // x-1 : x : log(2) | |
| 47 | andb $0x45, %ah | |
| 48 | jz 2f | |
| 49 | fstp %st(1) // x-1 : log(2) | |
| 50 | fyl2xp1 // log(x) | |
| 51 | ret | |
| 52 | ||
| 53 | 2: fstp %st(0) // x : log(2) | |
| 54 | fyl2x // log(x) | |
| 55 | ret | |
| 56 | END (__ieee754_logl) |