1*81ad6265SDimitry Andric//===------------- divmodhi4.S - sint16 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 {sint16, sint16} __divmodhi4(sint16, sint16)`. 12*81ad6265SDimitry Andric// The sint16 quotient is returned via R23:R22, and the sint16 remainder is 13*81ad6265SDimitry Andric// returned via R25:R24, while registers R21/R26/27/Rtmp and bit T in SREG 14*81ad6265SDimitry Andric// are clobbered. 15*81ad6265SDimitry Andric// 16*81ad6265SDimitry Andric//===----------------------------------------------------------------------===// 17*81ad6265SDimitry Andric 18*81ad6265SDimitry Andric .text 19*81ad6265SDimitry Andric .align 2 20*81ad6265SDimitry Andric 21*81ad6265SDimitry Andric#ifdef __AVR_TINY__ 22*81ad6265SDimitry Andric .set __tmp_reg__, 16 23*81ad6265SDimitry Andric#else 24*81ad6265SDimitry Andric .set __tmp_reg__, 0 25*81ad6265SDimitry Andric#endif 26*81ad6265SDimitry Andric 27*81ad6265SDimitry Andric .globl __divmodhi4 28*81ad6265SDimitry Andric .type __divmodhi4, @function 29*81ad6265SDimitry Andric 30*81ad6265SDimitry Andric__divmodhi4: 31*81ad6265SDimitry Andric bst r25, 7 32*81ad6265SDimitry Andric mov __tmp_reg__, r23 33*81ad6265SDimitry Andric brtc __divmodhi4_a 34*81ad6265SDimitry Andric com __tmp_reg__ 35*81ad6265SDimitry Andric rcall __divmodhi4_b 36*81ad6265SDimitry Andric 37*81ad6265SDimitry Andric__divmodhi4_a: 38*81ad6265SDimitry Andric sbrc r23, 7 39*81ad6265SDimitry Andric rcall __divmodhi4_c 40*81ad6265SDimitry Andric rcall __udivmodhi4 ; Call __udivmodhi4 to do real calculation. 41*81ad6265SDimitry Andric sbrc __tmp_reg__, 7 42*81ad6265SDimitry Andric rcall __divmodhi4_c 43*81ad6265SDimitry Andric brtc __divmodhi4_exit 44*81ad6265SDimitry Andric 45*81ad6265SDimitry Andric__divmodhi4_b: 46*81ad6265SDimitry Andric com r25 47*81ad6265SDimitry Andric neg r24 48*81ad6265SDimitry Andric sbci r25, 255 49*81ad6265SDimitry Andric ret ; Return quotient via R23:R22 and remainder via R25:R24. 50*81ad6265SDimitry Andric 51*81ad6265SDimitry Andric__divmodhi4_c: 52*81ad6265SDimitry Andric com r23 53*81ad6265SDimitry Andric neg r22 54*81ad6265SDimitry Andric sbci r23, 255 55*81ad6265SDimitry Andric 56*81ad6265SDimitry Andric__divmodhi4_exit: 57*81ad6265SDimitry Andric ret ; Return quotient via R23:R22 and remainder via R25:r24. 58