| 1 | #
|
|---|
| 2 | # Copyright (c) 2014 Martin Decky
|
|---|
| 3 | # All rights reserved.
|
|---|
| 4 | #
|
|---|
| 5 | # Redistribution and use in source and binary forms, with or without
|
|---|
| 6 | # modification, are permitted provided that the following conditions
|
|---|
| 7 | # are met:
|
|---|
| 8 | #
|
|---|
| 9 | # - Redistributions of source code must retain the above copyright
|
|---|
| 10 | # notice, this list of conditions and the following disclaimer.
|
|---|
| 11 | # - Redistributions in binary form must reproduce the above copyright
|
|---|
| 12 | # notice, this list of conditions and the following disclaimer in the
|
|---|
| 13 | # documentation and/or other materials provided with the distribution.
|
|---|
| 14 | # - The name of the author may not be used to endorse or promote products
|
|---|
| 15 | # derived from this software without specific prior written permission.
|
|---|
| 16 | #
|
|---|
| 17 | # THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|---|
| 18 | # IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|---|
| 19 | # OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|---|
| 20 | # IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|---|
| 21 | # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|---|
| 22 | # NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|---|
| 23 | # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|---|
| 24 | # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|---|
| 25 | # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|---|
| 26 | # THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|---|
| 27 | #
|
|---|
| 28 |
|
|---|
| 29 | #include <libarch/x87.h>
|
|---|
| 30 |
|
|---|
| 31 | .text
|
|---|
| 32 |
|
|---|
| 33 | .global cos
|
|---|
| 34 |
|
|---|
| 35 | cos:
|
|---|
| 36 | pushq %rbp
|
|---|
| 37 | movq %rsp, %rbp
|
|---|
| 38 |
|
|---|
| 39 | # compute cosine (using red zone)
|
|---|
| 40 |
|
|---|
| 41 | movsd %xmm0, -8(%rbp)
|
|---|
| 42 | fldl -8(%rbp)
|
|---|
| 43 |
|
|---|
| 44 | fcos
|
|---|
| 45 |
|
|---|
| 46 | # detect if source operand is out of range
|
|---|
| 47 |
|
|---|
| 48 | fnstsw %ax
|
|---|
| 49 | andw $X87_STATUS_WORD_C2_MASK, %ax
|
|---|
| 50 | jnz fix_range
|
|---|
| 51 |
|
|---|
| 52 | fstpl -8(%rbp)
|
|---|
| 53 | movsd -8(%rbp), %xmm0
|
|---|
| 54 |
|
|---|
| 55 | leave
|
|---|
| 56 | retq
|
|---|
| 57 |
|
|---|
| 58 | # argument reduction
|
|---|
| 59 |
|
|---|
| 60 | fix_range:
|
|---|
| 61 | fldpi
|
|---|
| 62 | fadd %st(0)
|
|---|
| 63 | fxch %st(1)
|
|---|
| 64 |
|
|---|
| 65 | reduce:
|
|---|
| 66 | fprem1
|
|---|
| 67 | fnstsw %ax
|
|---|
| 68 | andw $X87_STATUS_WORD_C2_MASK, %ax
|
|---|
| 69 | jnz reduce
|
|---|
| 70 |
|
|---|
| 71 | fstpl %st(1)
|
|---|
| 72 | fcos
|
|---|
| 73 |
|
|---|
| 74 | fstpl -8(%rbp)
|
|---|
| 75 | movsd -8(%rbp), %xmm0
|
|---|
| 76 |
|
|---|
| 77 | leave
|
|---|
| 78 | retq
|
|---|
