1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * Copyright (C) 1999-2000 Hewlett-Packard Co 4 * Copyright (C) 1999-2000 David Mosberger-Tang <davidm@hpl.hp.com> 5 * 6 * 64-bit integer division. 7 * 8 * This code is based on the application note entitled "Divide, Square Root 9 * and Remainder Algorithms for the IA-64 Architecture". This document 10 * is available as Intel document number 248725-002 or via the web at 11 * http://developer.intel.com/software/opensource/numerics/ 12 * 13 * For more details on the theory behind these algorithms, see "IA-64 14 * and Elementary Functions" by Peter Markstein; HP Professional Books 15 * (http://www.goodreads.com/book/show/2019887.Ia_64_and_Elementary_Functions) 16 */ 17 18#include <asm/asmmacro.h> 19#include <asm/export.h> 20 21#ifdef MODULO 22# define OP mod 23#else 24# define OP div 25#endif 26 27#ifdef UNSIGNED 28# define SGN u 29# define INT_TO_FP(a,b) fcvt.xuf.s1 a=b 30# define FP_TO_INT(a,b) fcvt.fxu.trunc.s1 a=b 31#else 32# define SGN 33# define INT_TO_FP(a,b) fcvt.xf a=b 34# define FP_TO_INT(a,b) fcvt.fx.trunc.s1 a=b 35#endif 36 37#define PASTE1(a,b) a##b 38#define PASTE(a,b) PASTE1(a,b) 39#define NAME PASTE(PASTE(__,SGN),PASTE(OP,di3)) 40 41GLOBAL_ENTRY(NAME) 42 .regstk 2,0,0,0 43 // Transfer inputs to FP registers. 44 setf.sig f8 = in0 45 setf.sig f9 = in1 46 ;; 47 // Convert the inputs to FP, to avoid FP software-assist faults. 48 INT_TO_FP(f8, f8) 49 INT_TO_FP(f9, f9) 50 ;; 51 frcpa.s1 f11, p6 = f8, f9 // y0 = frcpa(b) 52 ;; 53(p6) fmpy.s1 f7 = f8, f11 // q0 = a*y0 54(p6) fnma.s1 f6 = f9, f11, f1 // e0 = -b*y0 + 1 55 ;; 56(p6) fma.s1 f10 = f7, f6, f7 // q1 = q0*e0 + q0 57(p6) fmpy.s1 f7 = f6, f6 // e1 = e0*e0 58 ;; 59#ifdef MODULO 60 sub in1 = r0, in1 // in1 = -b 61#endif 62(p6) fma.s1 f10 = f10, f7, f10 // q2 = q1*e1 + q1 63(p6) fma.s1 f6 = f11, f6, f11 // y1 = y0*e0 + y0 64 ;; 65(p6) fma.s1 f6 = f6, f7, f6 // y2 = y1*e1 + y1 66(p6) fnma.s1 f7 = f9, f10, f8 // r = -b*q2 + a 67 ;; 68#ifdef MODULO 69 setf.sig f8 = in0 // f8 = a 70 setf.sig f9 = in1 // f9 = -b 71#endif 72(p6) fma.s1 f11 = f7, f6, f10 // q3 = r*y2 + q2 73 ;; 74 FP_TO_INT(f11, f11) // q = trunc(q3) 75 ;; 76#ifdef MODULO 77 xma.l f11 = f11, f9, f8 // r = q*(-b) + a 78 ;; 79#endif 80 getf.sig r8 = f11 // transfer result to result register 81 br.ret.sptk.many rp 82END(NAME) 83EXPORT_SYMBOL(NAME) 84