1b2441318SGreg Kroah-Hartman/* SPDX-License-Identifier: GPL-2.0 */ 21da177e4SLinus Torvalds/* 31da177e4SLinus Torvalds * Copyright (C) 2000 Hewlett-Packard Co 41da177e4SLinus Torvalds * Copyright (C) 2000 David Mosberger-Tang <davidm@hpl.hp.com> 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * 32-bit integer division. 71da177e4SLinus Torvalds * 81da177e4SLinus Torvalds * This code is based on the application note entitled "Divide, Square Root 91da177e4SLinus Torvalds * and Remainder Algorithms for the IA-64 Architecture". This document 101da177e4SLinus Torvalds * is available as Intel document number 248725-002 or via the web at 111da177e4SLinus Torvalds * http://developer.intel.com/software/opensource/numerics/ 121da177e4SLinus Torvalds * 131da177e4SLinus Torvalds * For more details on the theory behind these algorithms, see "IA-64 141da177e4SLinus Torvalds * and Elementary Functions" by Peter Markstein; HP Professional Books 15a9eb221aSSina Hamedian * (http://www.goodreads.com/book/show/2019887.Ia_64_and_Elementary_Functions) 161da177e4SLinus Torvalds */ 171da177e4SLinus Torvalds 18*ab03e604SMasahiro Yamada#include <linux/export.h> 191da177e4SLinus Torvalds#include <asm/asmmacro.h> 201da177e4SLinus Torvalds 211da177e4SLinus Torvalds#ifdef MODULO 221da177e4SLinus Torvalds# define OP mod 231da177e4SLinus Torvalds#else 241da177e4SLinus Torvalds# define OP div 251da177e4SLinus Torvalds#endif 261da177e4SLinus Torvalds 271da177e4SLinus Torvalds#ifdef UNSIGNED 281da177e4SLinus Torvalds# define SGN u 291da177e4SLinus Torvalds# define EXTEND zxt4 301da177e4SLinus Torvalds# define INT_TO_FP(a,b) fcvt.xuf.s1 a=b 311da177e4SLinus Torvalds# define FP_TO_INT(a,b) fcvt.fxu.trunc.s1 a=b 321da177e4SLinus Torvalds#else 331da177e4SLinus Torvalds# define SGN 341da177e4SLinus Torvalds# define EXTEND sxt4 351da177e4SLinus Torvalds# define INT_TO_FP(a,b) fcvt.xf a=b 361da177e4SLinus Torvalds# define FP_TO_INT(a,b) fcvt.fx.trunc.s1 a=b 371da177e4SLinus Torvalds#endif 381da177e4SLinus Torvalds 391da177e4SLinus Torvalds#define PASTE1(a,b) a##b 401da177e4SLinus Torvalds#define PASTE(a,b) PASTE1(a,b) 411da177e4SLinus Torvalds#define NAME PASTE(PASTE(__,SGN),PASTE(OP,si3)) 421da177e4SLinus Torvalds 431da177e4SLinus TorvaldsGLOBAL_ENTRY(NAME) 441da177e4SLinus Torvalds .regstk 2,0,0,0 451da177e4SLinus Torvalds // Transfer inputs to FP registers. 461da177e4SLinus Torvalds mov r2 = 0xffdd // r2 = -34 + 65535 (fp reg format bias) 471da177e4SLinus Torvalds EXTEND in0 = in0 // in0 = a 481da177e4SLinus Torvalds EXTEND in1 = in1 // in1 = b 491da177e4SLinus Torvalds ;; 501da177e4SLinus Torvalds setf.sig f8 = in0 511da177e4SLinus Torvalds setf.sig f9 = in1 521da177e4SLinus Torvalds#ifdef MODULO 531da177e4SLinus Torvalds sub in1 = r0, in1 // in1 = -b 541da177e4SLinus Torvalds#endif 551da177e4SLinus Torvalds ;; 561da177e4SLinus Torvalds // Convert the inputs to FP, to avoid FP software-assist faults. 571da177e4SLinus Torvalds INT_TO_FP(f8, f8) 581da177e4SLinus Torvalds INT_TO_FP(f9, f9) 591da177e4SLinus Torvalds ;; 601da177e4SLinus Torvalds setf.exp f7 = r2 // f7 = 2^-34 611da177e4SLinus Torvalds frcpa.s1 f6, p6 = f8, f9 // y0 = frcpa(b) 621da177e4SLinus Torvalds ;; 631da177e4SLinus Torvalds(p6) fmpy.s1 f8 = f8, f6 // q0 = a*y0 641da177e4SLinus Torvalds(p6) fnma.s1 f6 = f9, f6, f1 // e0 = -b*y0 + 1 651da177e4SLinus Torvalds ;; 661da177e4SLinus Torvalds#ifdef MODULO 671da177e4SLinus Torvalds setf.sig f9 = in1 // f9 = -b 681da177e4SLinus Torvalds#endif 691da177e4SLinus Torvalds(p6) fma.s1 f8 = f6, f8, f8 // q1 = e0*q0 + q0 701da177e4SLinus Torvalds(p6) fma.s1 f6 = f6, f6, f7 // e1 = e0*e0 + 2^-34 711da177e4SLinus Torvalds ;; 721da177e4SLinus Torvalds#ifdef MODULO 731da177e4SLinus Torvalds setf.sig f7 = in0 741da177e4SLinus Torvalds#endif 751da177e4SLinus Torvalds(p6) fma.s1 f6 = f6, f8, f8 // q2 = e1*q1 + q1 761da177e4SLinus Torvalds ;; 771da177e4SLinus Torvalds FP_TO_INT(f6, f6) // q = trunc(q2) 781da177e4SLinus Torvalds ;; 791da177e4SLinus Torvalds#ifdef MODULO 801da177e4SLinus Torvalds xma.l f6 = f6, f9, f7 // r = q*(-b) + a 811da177e4SLinus Torvalds ;; 821da177e4SLinus Torvalds#endif 831da177e4SLinus Torvalds getf.sig r8 = f6 // transfer result to result register 841da177e4SLinus Torvalds br.ret.sptk.many rp 851da177e4SLinus TorvaldsEND(NAME) 86e007c533SAl ViroEXPORT_SYMBOL(NAME) 87