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1//===------------ udivmodqi4.S - uint8 div & mod --------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// As described at10// https://gcc.gnu.org/wiki/avr-gcc#Exceptions_to_the_Calling_Convention, the11// prototype is `struct {uint8, uint8} __udivmodqi4(uint8, uint8)`.12// The uint8 quotient is returned via R24, and the uint8 remainder is returned13// via R25, while R23 is clobbered.14//15//===----------------------------------------------------------------------===//16 17 .text18 .align 219 20 .globl __udivmodqi421 .type __udivmodqi4, @function22 23__udivmodqi4:24 sub r25, r25 ; Initialize the remainder to zero.25 ldi r23, 9 ; Only loop 8 rounds for uint8.26 27__udivmodqi4_loop:28 adc r24, r2429 dec r2330 breq __udivmodqi4_end31 adc r25, r2532 cp r25, r22 ; Compare with the divisor.33 brcs __udivmodqi4_loop34 sub r25, r22 ; Subtract the divisor.35 rjmp __udivmodqi4_loop36 37__udivmodqi4_end:38 com r24 ; The uint8 quotient is returned via R24.39 ret ; The uint8 remainder is returned via R25.40