1 ;; SPDX-License-Identifier: GPL-2.0-or-later 2 ;; Copyright 2010 Free Software Foundation, Inc. 3 ;; Contributed by Bernd Schmidt <bernds@codesourcery.com>. 4 ;; 5 6 #include <linux/linkage.h> 7 8 ;; ABI considerations for the divide functions 9 ;; The following registers are call-used: 10 ;; __c6xabi_divi A0,A1,A2,A4,A6,B0,B1,B2,B4,B5 11 ;; __c6xabi_divu A0,A1,A2,A4,A6,B0,B1,B2,B4 12 ;; __c6xabi_remi A1,A2,A4,A5,A6,B0,B1,B2,B4 13 ;; __c6xabi_remu A1,A4,A5,A7,B0,B1,B2,B4 14 ;; 15 ;; In our implementation, divu and remu are leaf functions, 16 ;; while both divi and remi call into divu. 17 ;; A0 is not clobbered by any of the functions. 18 ;; divu does not clobber B2 either, which is taken advantage of 19 ;; in remi. 20 ;; divi uses B5 to hold the original return address during 21 ;; the call to divu. 22 ;; remi uses B2 and A5 to hold the input values during the 23 ;; call to divu. It stores B3 in on the stack. 24 25 .text 26 ENTRY(__c6xabi_divi) 27 call .s2 __c6xabi_divu 28 || mv .d2 B3, B5 29 || cmpgt .l1 0, A4, A1 30 || cmpgt .l2 0, B4, B1 31 32 [A1] neg .l1 A4, A4 33 || [B1] neg .l2 B4, B4 34 || xor .s1x A1, B1, A1 35 [A1] addkpc .s2 _divu_ret, B3, 4 36 _divu_ret: 37 neg .l1 A4, A4 38 || mv .l2 B3,B5 39 || ret .s2 B5 40 nop 5 41 ENDPROC(__c6xabi_divi) 42