forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
86 lines
2.2 KiB
86 lines
2.2 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
|
/* |
|
* Copyright (C) 2000 Hewlett-Packard Co |
|
* Copyright (C) 2000 David Mosberger-Tang <davidm@hpl.hp.com> |
|
* |
|
* 32-bit integer division. |
|
* |
|
* This code is based on the application note entitled "Divide, Square Root |
|
* and Remainder Algorithms for the IA-64 Architecture". This document |
|
* is available as Intel document number 248725-002 or via the web at |
|
* http://developer.intel.com/software/opensource/numerics/ |
|
* |
|
* For more details on the theory behind these algorithms, see "IA-64 |
|
* and Elementary Functions" by Peter Markstein; HP Professional Books |
|
* (http://www.goodreads.com/book/show/2019887.Ia_64_and_Elementary_Functions) |
|
*/ |
|
|
|
#include <asm/asmmacro.h> |
|
#include <asm/export.h> |
|
|
|
#ifdef MODULO |
|
# define OP mod |
|
#else |
|
# define OP div |
|
#endif |
|
|
|
#ifdef UNSIGNED |
|
# define SGN u |
|
# define EXTEND zxt4 |
|
# define INT_TO_FP(a,b) fcvt.xuf.s1 a=b |
|
# define FP_TO_INT(a,b) fcvt.fxu.trunc.s1 a=b |
|
#else |
|
# define SGN |
|
# define EXTEND sxt4 |
|
# define INT_TO_FP(a,b) fcvt.xf a=b |
|
# define FP_TO_INT(a,b) fcvt.fx.trunc.s1 a=b |
|
#endif |
|
|
|
#define PASTE1(a,b) a##b |
|
#define PASTE(a,b) PASTE1(a,b) |
|
#define NAME PASTE(PASTE(__,SGN),PASTE(OP,si3)) |
|
|
|
GLOBAL_ENTRY(NAME) |
|
.regstk 2,0,0,0 |
|
// Transfer inputs to FP registers. |
|
mov r2 = 0xffdd // r2 = -34 + 65535 (fp reg format bias) |
|
EXTEND in0 = in0 // in0 = a |
|
EXTEND in1 = in1 // in1 = b |
|
;; |
|
setf.sig f8 = in0 |
|
setf.sig f9 = in1 |
|
#ifdef MODULO |
|
sub in1 = r0, in1 // in1 = -b |
|
#endif |
|
;; |
|
// Convert the inputs to FP, to avoid FP software-assist faults. |
|
INT_TO_FP(f8, f8) |
|
INT_TO_FP(f9, f9) |
|
;; |
|
setf.exp f7 = r2 // f7 = 2^-34 |
|
frcpa.s1 f6, p6 = f8, f9 // y0 = frcpa(b) |
|
;; |
|
(p6) fmpy.s1 f8 = f8, f6 // q0 = a*y0 |
|
(p6) fnma.s1 f6 = f9, f6, f1 // e0 = -b*y0 + 1 |
|
;; |
|
#ifdef MODULO |
|
setf.sig f9 = in1 // f9 = -b |
|
#endif |
|
(p6) fma.s1 f8 = f6, f8, f8 // q1 = e0*q0 + q0 |
|
(p6) fma.s1 f6 = f6, f6, f7 // e1 = e0*e0 + 2^-34 |
|
;; |
|
#ifdef MODULO |
|
setf.sig f7 = in0 |
|
#endif |
|
(p6) fma.s1 f6 = f6, f8, f8 // q2 = e1*q1 + q1 |
|
;; |
|
FP_TO_INT(f6, f6) // q = trunc(q2) |
|
;; |
|
#ifdef MODULO |
|
xma.l f6 = f6, f9, f7 // r = q*(-b) + a |
|
;; |
|
#endif |
|
getf.sig r8 = f6 // transfer result to result register |
|
br.ret.sptk.many rp |
|
END(NAME) |
|
EXPORT_SYMBOL(NAME)
|
|
|