1;; Copyright 2010 Free Software Foundation, Inc. 2;; Contributed by Bernd Schmidt <bernds@codesourcery.com>. 3;; 4;; This program is free software; you can redistribute it and/or modify 5;; it under the terms of the GNU General Public License as published by 6;; the Free Software Foundation; either version 2 of the License, or 7;; (at your option) any later version. 8;; 9;; This program is distributed in the hope that it will be useful, 10;; but WITHOUT ANY WARRANTY; without even the implied warranty of 11;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12;; GNU General Public License for more details. 13;; 14;; You should have received a copy of the GNU General Public License 15;; along with this program; if not, write to the Free Software 16;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 17 18#include <linux/linkage.h> 19 20 ;; ABI considerations for the divide functions 21 ;; The following registers are call-used: 22 ;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5 23 ;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4 24 ;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4 25 ;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4 26 ;; 27 ;; In our implementation, divu and remu are leaf functions, 28 ;; while both divi and remi call into divu. 29 ;; A0 is not clobbered by any of the functions. 30 ;; divu does not clobber B2 either, which is taken advantage of 31 ;; in remi. 32 ;; divi uses B5 to hold the original return address during 33 ;; the call to divu. 34 ;; remi uses B2 and A5 to hold the input values during the 35 ;; call to divu. It stores B3 in on the stack. 36 37 38 .text 39 40ENTRY(__c6xabi_remu) 41 ;; The ABI seems designed to prevent these functions calling each other, 42 ;; so we duplicate most of the divsi3 code here. 43 mv .s2x A4, B1 44 lmbd .l2 1, B4, B1 45|| [!B1] b .s2 B3 ; RETURN A 46|| [!B1] mvk .d2 1, B4 47 48 mv .l1x B1, A7 49|| shl .s2 B4, B1, B4 50 51 cmpltu .l1x A4, B4, A1 52 [!A1] sub .l1x A4, B4, A4 53 shru .s2 B4, 1, B4 54 55_remu_loop: 56 cmpgt .l2 B1, 7, B0 57|| [B1] subc .l1x A4,B4,A4 58|| [B1] add .s2 -1, B1, B1 59 ;; RETURN A may happen here (note: must happen before the next branch) 60 [B1] subc .l1x A4,B4,A4 61|| [B1] add .s2 -1, B1, B1 62|| [B0] b .s1 _remu_loop 63 [B1] subc .l1x A4,B4,A4 64|| [B1] add .s2 -1, B1, B1 65 [B1] subc .l1x A4,B4,A4 66|| [B1] add .s2 -1, B1, B1 67 [B1] subc .l1x A4,B4,A4 68|| [B1] add .s2 -1, B1, B1 69 [B1] subc .l1x A4,B4,A4 70|| [B1] add .s2 -1, B1, B1 71 [B1] subc .l1x A4,B4,A4 72|| [B1] add .s2 -1, B1, B1 73 ;; loop backwards branch happens here 74 75 ret .s2 B3 76 [B1] subc .l1x A4,B4,A4 77|| [B1] add .s2 -1, B1, B1 78 [B1] subc .l1x A4,B4,A4 79 80 extu .s1 A4, A7, A4 81 nop 2 82ENDPROC(__c6xabi_remu) 83