projects / unix-history / blame
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|---|---|---|
| e0a11985 KB |
1 | /*- |
| 2 | * Copyright (c) 1990 The Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * This code is derived from software contributed to Berkeley by | |
| 6 | * the Systems Programming Group of the University of Utah Computer | |
| 7 | * Science Department. | |
| 8 | * | |
| 9 | * %sccs.include.redist.c% | |
| 10 | * | |
| 11 | * @(#)floor.s 5.1 (Berkeley) %G% | |
| 12 | */ | |
| 13 | ||
| 14 | .text | |
| 15 | .globl _floor,_ceil,_rint | |
| 16 | ||
| 17 | | floor(x) | |
| 18 | | the largest integer no larger than x | |
| 19 | _floor: | |
| 20 | fmovel fpcr,d0 | save old FPCR | |
| 21 | fmoved sp@(4),fp0 | get argument | |
| 22 | fbun Lret | if NaN, return NaN | |
| 23 | fboge Lrtz | >=0, round to zero | |
| 24 | fmovel #0x20,fpcr | <0, round to -inf | |
| 25 | jra Ldoit | |
| 26 | ||
| 27 | | ceil(x) | |
| 28 | | -floor(-x), for all real x | |
| 29 | _ceil: | |
| 30 | fmovel fpcr,d0 | save old FPCR | |
| 31 | fmoved sp@(4),fp0 | get argument | |
| 32 | fbun Lret | if NaN, return NaN | |
| 33 | fbolt Lrtz | <0, round to zero | |
| 34 | fmovel #0x30,fpcr | >=0, round to inf | |
| 35 | jra Ldoit | |
| 36 | ||
| 37 | Lrtz: | |
| 38 | fmovel #0x10,fpcr | |
| 39 | Ldoit: | |
| 40 | fintd sp@(4),fp0 | truncate | |
| 41 | fmovel d0,fpcr | restore old FPCR | |
| 42 | Lret: | |
| 43 | fmoved fp0,sp@- | |
| 44 | movel sp@+,d0 | |
| 45 | movel sp@+,d1 | |
| 46 | rts | |
| 47 | ||
| 48 | | rint(x) | |
| 49 | | delivers integer nearest x in direction of prevailing rounding mode | |
| 50 | _rint: | |
| 51 | fintd sp@(4),fp0 | use prevailing rounding mode | |
| 52 | jra Lret |