1/******************************************************************************* 2 * 3 * Copyright (c) 1993 Intel Corporation 4 * 5 * Intel hereby grants you permission to copy, modify, and distribute this 6 * software and its documentation. Intel grants this permission provided 7 * that the above copyright notice appears in all copies and that both the 8 * copyright notice and this permission notice appear in supporting 9 * documentation. In addition, Intel grants this permission provided that 10 * you prominently mark as "not part of the original" any modifications 11 * made to this software or documentation, and that the name of Intel 12 * Corporation not be used in advertising or publicity pertaining to 13 * distribution of the software or the documentation without specific, 14 * written prior permission. 15 * 16 * Intel Corporation provides this AS IS, WITHOUT ANY WARRANTY, EXPRESS OR 17 * IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY 18 * OR FITNESS FOR A PARTICULAR PURPOSE. Intel makes no guarantee or 19 * representations regarding the use of, or the results of the use of, 20 * the software and documentation in terms of correctness, accuracy, 21 * reliability, currentness, or otherwise; and you rely on the software, 22 * documentation and results solely at your own risk. 23 * 24 * IN NO EVENT SHALL INTEL BE LIABLE FOR ANY LOSS OF USE, LOSS OF BUSINESS, 25 * LOSS OF PROFITS, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES 26 * OF ANY KIND. IN NO EVENT SHALL INTEL'S TOTAL LIABILITY EXCEED THE SUM 27 * PAID TO INTEL FOR THE PRODUCT LICENSED HEREUNDER. 28 * 29 ******************************************************************************/ 30 31#include <picolibc.h> 32 33 .file "memset.s" 34#ifdef __PIC 35 .pic 36#endif 37#ifdef __PID 38 .pid 39#endif 40/* 41 * (c) copyright 1989,1993 Intel Corp., all rights reserved 42 */ 43 44/* 45 procedure memset (optimized assembler version: 80960K series, 80960CA) 46 47 dest_addr = memset (dest_addr, char, len) 48 49 Fill len bytes pointed to by dest_addr with the value of char. 50 Return the original address of dest_addr. 51 52 This program avoids performing unaligned accesses. It stores 53 from zero to seven bytes, and then stores aligned longwords, 54 and then stores from zero to seven bytes, as necessary to 55 store len bytes starting at dest_addr. 56 57 At the time of this writing, only g0 thru g7 and g13 are available 58 for use in this leafproc; other registers would have to be saved and 59 restored. These nine registers, plus tricky use of g14 are sufficient 60 to implement the routine. 61*/ 62 63 .globl _memset 64 .globl __memset 65 .leafproc _memset, __memset 66 .align 2 67_memset: 68#ifndef __PIC 69 lda Lrett,g14 70#else 71 lda Lrett-(.+8)(ip),g14 72#endif 73__memset: 74 cmpo 7,g2 # are there fewer than seven characters to move? 75 lda (g14),g13 # save return address 76 notand g0,7,g3 # test for non-aligned dest_ptr 77 lda 0,g14 # conform to register conventions 78 shlo 24,g1,g4 # prepare word of char 79 lda (g0),g6 # preserve dest_ptr for return 80 shro 8,g4,g5 81 bge.f Lcloop_setup 82 cmpo g3,g0 # is dest longword aligned 83 lda 7(g3),g3 # bump dest_ptr to next longword boundary 84 or g4,g5,g4 85 be.t Lwloop_setup 86 87Lbgn_cloop: 88 cmpo g6,g3 # Have we reached longword boundary? 89 stob g1,(g6) # store one byte of char 90 subo 1,g2,g2 # decrement len 91 lda 1(g6),g6 # increment dest_ptr 92 bne.t Lbgn_cloop # loop if more bytes to store before longword 93 94 cmpobge.f 7,g2,Lcloop 95 96Lwloop_setup: 97 shro 16,g4,g5 98 or g4,g5,g4 99 mov g4,g5 # now have a longword of char 100 101Lwloop: 102 cmpo 15,g2 # Do we have to store more longwords? 103 stl g4,(g6) # Store longword of char 104 subo 8,g2,g2 # Decrement len 105 lda 8(g6),g6 # Increment dest_ptr 106 bl.t Lwloop # loop if more longwords to store 107 108Lcloop_setup: 109 cmpobge.t 0,g2,Lexit 110 111Lcloop: 112 cmpo 1,g2 # Is len exhausted? 113 stob g1,(g6) # Store byte 114 subo 1,g2,g2 # Decrement len 115 lda 1(g6),g6 # Increment dest_ptr 116 bne.t Lcloop # loop if more bytes to store 117 118Lexit: 119 bx (g13) 120Lrett: 121 ret 122 123/* end of memset */ 124