| /* Copyright (c) 2002 Michael Stumpf <mistumpf@de.pepperl-fuchs.com> |
| Copyright (c) 2006 Dmitry Xmelkov |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are met: |
| |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in |
| the documentation and/or other materials provided with the |
| distribution. |
| * Neither the name of the copyright holders nor the names of |
| contributors may be used to endorse or promote products derived |
| from this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| POSSIBILITY OF SUCH DAMAGE. */ |
| |
| /* $Id: cosh.S 1174 2007-01-14 15:13:54Z dmix $ */ |
| |
| #include "fp32def.h" |
| #include "asmdef.h" |
| |
| /* float cosh (float x); |
| The cosh() function returns the hyperbolic cosine of x, which is |
| defined mathematically as (exp(x) + exp(-x)) / 2. |
| |
| Notes: |
| ldexp() is called twice to avoid overflow with too big x argument. |
| */ |
| |
| #define exp_lo r20 |
| #define exp_hi r21 |
| |
| ENTRY cosh |
| ; A = exp(-fabs(x))/2 negative to exclude an extra inversion |
| ori rA3, 0x80 |
| rcall _U(exp) |
| ldi exp_lo, lo8(-1) |
| ldi exp_hi, hi8(-1) |
| rcall _U(ldexp) |
| ; save A and calculate exp(fabs(x))/2 |
| push rA3 |
| push rA2 |
| push rA1 |
| push rA0 |
| ldi exp_lo, lo8(2) |
| ldi exp_hi, hi8(2) |
| rcall _U(ldexp) |
| rcall _U(inverse) |
| ; exp(x)/2 + exp(-x)/2 |
| pop rB0 |
| pop rB1 |
| pop rB2 |
| pop rB3 |
| rjmp _U(__addsf3) |
| ENDFUNC |