projects / thirdparty / glibc.git / blame
| Commit | Line | Data |
|---|---|---|
| e7fd8a39 UD |
1 | /* |
| 2 | * Written by J.T. Conklin <jtc@netbsd.org>. | |
| 3 | * Adapted for use as log2 by Ulrich Drepper <drepper@cygnus.com>. | |
| 4 | * Public domain. | |
| 5 | * | |
| 6 | * Changed to use fyl2xp1 for values near 1, <drepper@cygnus.com>. | |
| 7 | */ | |
| 8 | ||
| 9 | #include <machine/asm.h> | |
| 10 | ||
| 11 | #ifdef __ELF__ | |
| 0ac5ae23 | 12 | .section .rodata.cst8,"aM",@progbits,8 |
| e7fd8a39 UD |
13 | #else |
| 14 | .text | |
| 15 | #endif | |
| 0ac5ae23 | 16 | .p2align 3 |
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17 | ASM_TYPE_DIRECTIVE(one,@object) |
| 18 | one: .double 1.0 | |
| 19 | ASM_SIZE_DIRECTIVE(one) | |
| 20 | /* It is not important that this constant is precise. It is only | |
| 21 | a value which is known to be on the safe side for using the | |
| 22 | fyl2xp1 instruction. */ | |
| 23 | ASM_TYPE_DIRECTIVE(limit,@object) | |
| 24 | limit: .double 0.29 | |
| 25 | ASM_SIZE_DIRECTIVE(limit) | |
| 26 | ||
| 27 | ||
| 28 | #ifdef PIC | |
| 0ac5ae23 | 29 | # define MO(op) op##@GOTOFF(%edx) |
| e7fd8a39 | 30 | #else |
| 0ac5ae23 | 31 | # define MO(op) op |
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32 | #endif |
| 33 | ||
| 34 | .text | |
| 601d2942 | 35 | ENTRY(__ieee754_log2l) |
| e7fd8a39 | 36 | #ifdef PIC |
| fee732e5 | 37 | LOAD_PIC_REG (dx) |
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38 | #endif |
| 39 | fldl MO(one) | |
| 40 | fldt 4(%esp) // x : 1 | |
| 15daa639 UD |
41 | fxam |
| 42 | fnstsw | |
| e7fd8a39 | 43 | fld %st // x : x : 1 |
| 15daa639 UD |
44 | sahf |
| 45 |