1*81ad6265SDimitry Andric//===------------- divmodqi4.S - sint8 div & mod --------------------------===// 2*81ad6265SDimitry Andric// 3*81ad6265SDimitry Andric// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*81ad6265SDimitry Andric// See https://llvm.org/LICENSE.txt for license information. 5*81ad6265SDimitry Andric// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*81ad6265SDimitry Andric// 7*81ad6265SDimitry Andric//===----------------------------------------------------------------------===// 8*81ad6265SDimitry Andric// 9*81ad6265SDimitry Andric// As described at 10*81ad6265SDimitry Andric// https://gcc.gnu.org/wiki/avr-gcc#Exceptions_to_the_Calling_Convention, the 11*81ad6265SDimitry Andric// prototype is `struct {sint8, sint8} __divmodqi4(sint8, sint8)`. 12*81ad6265SDimitry Andric// The sint8 quotient is returned via R24, and the sint8 remainder is returned 13*81ad6265SDimitry Andric// via R25, while registers R23/Rtmp and bit T in SREG are clobbered. 14*81ad6265SDimitry Andric// 15*81ad6265SDimitry Andric//===----------------------------------------------------------------------===// 16*81ad6265SDimitry Andric 17*81ad6265SDimitry Andric .text 18*81ad6265SDimitry Andric .align 2 19*81ad6265SDimitry Andric 20*81ad6265SDimitry Andric#ifdef __AVR_TINY__ 21*81ad6265SDimitry Andric .set __tmp_reg__, 16 22*81ad6265SDimitry Andric#else 23*81ad6265SDimitry Andric .set __tmp_reg__, 0 24*81ad6265SDimitry Andric#endif 25*81ad6265SDimitry Andric 26*81ad6265SDimitry Andric .globl __divmodqi4 27*81ad6265SDimitry Andric .type __divmodqi4, @function 28*81ad6265SDimitry Andric 29*81ad6265SDimitry Andric__divmodqi4: 30*81ad6265SDimitry Andric bst r24, 7 31*81ad6265SDimitry Andric mov __tmp_reg__, r24 32*81ad6265SDimitry Andric eor __tmp_reg__, r22 33*81ad6265SDimitry Andric sbrc r24, 7 34*81ad6265SDimitry Andric neg r24 35*81ad6265SDimitry Andric sbrc r22, 7 36*81ad6265SDimitry Andric neg r22 37*81ad6265SDimitry Andric rcall __udivmodqi4 ; Call __udivmodqi4 to do real calculation. 38*81ad6265SDimitry Andric brtc __divmodqi4_1 39*81ad6265SDimitry Andric neg r25 40*81ad6265SDimitry Andric 41*81ad6265SDimitry Andric__divmodqi4_1: 42*81ad6265SDimitry Andric sbrc __tmp_reg__, 7 43*81ad6265SDimitry Andric neg r24 44*81ad6265SDimitry Andric ret ; Return quotient via R24 and remainder via R25. 45