| Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 |
| Sina Hamedian | a9eb221 | 2016-01-30 22:07:31 -0800 | [diff] [blame] | 15 | * (http://www.goodreads.com/book/show/2019887.Ia_64_and_Elementary_Functions) |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | */ |
| 17 | |
| 18 | #include <asm/asmmacro.h> |
| Al Viro | e007c53 | 2016-01-17 01:13:41 -0500 | [diff] [blame] | 19 | #include <asm/export.h> |
| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
| 41 | GLOBAL_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 |
| 82 | END(NAME) |
| Al Viro | e007c53 | 2016-01-17 01:13:41 -0500 | [diff] [blame] | 83 | EXPORT_SYMBOL(NAME) |