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 .file "memset.s" 32#ifdef __PIC 33 .pic 34#endif 35#ifdef __PID 36 .pid 37#endif 38/* 39 * (c) copyright 1989,1993 Intel Corp., all rights reserved 40 */ 41 42/* 43 procedure memset (optimized assembler version: 80960K series, 80960CA) 44 45 dest_addr = memset (dest_addr, char, len) 46 47 Fill len bytes pointed to by dest_addr with the value of char. 48 Return the original address of dest_addr. 49 50 This program avoids performing unaligned accesses. It stores 51 from zero to seven bytes, and then stores aligned longwords, 52 and then stores from zero to seven bytes, as necessary to 53 store len bytes starting at dest_addr. 54 55 At the time of this writing, only g0 thru g7 and g13 are available 56 for use in this leafproc; other registers would have to be saved and 57 restored. These nine registers, plus tricky use of g14 are sufficient 58 to implement the routine. 59*/ 60 61 .globl _memset 62 .globl __memset 63 .leafproc _memset, __memset 64 .align 2 65_memset: 66#ifndef __PIC 67 lda Lrett,g14 68#else 69 lda Lrett-(.+8)(ip),g14 70#endif 71__memset: 72 cmpo 7,g2 # are there fewer than seven characters to move? 73 lda (g14),g13 # save return address 74 notand g0,7,g3 # test for non-aligned dest_ptr 75 lda 0,g14 # conform to register conventions 76 shlo 24,g1,g4 # prepare word of char 77 lda (g0),g6 # preserve dest_ptr for return 78 shro 8,g4,g5 79 bge.f Lcloop_setup 80 cmpo g3,g0 # is dest longword aligned 81 lda 7(g3),g3 # bump dest_ptr to next longword boundary 82 or g4,g5,g4 83 be.t Lwloop_setup 84 85Lbgn_cloop: 86 cmpo g6,g3 # Have we reached longword boundary? 87 stob g1,(g6) # store one byte of char 88 subo 1,g2,g2 # decrement len 89 lda 1(g6),g6 # increment dest_ptr 90 bne.t Lbgn_cloop # loop if more bytes to store before longword 91 92 cmpobge.f 7,g2,Lcloop 93 94Lwloop_setup: 95 shro 16,g4,g5 96 or g4,g5,g4 97 mov g4,g5 # now have a longword of char 98 99Lwloop: 100 cmpo 15,g2 # Do we have to store more longwords? 101 stl g4,(g6) # Store longword of char 102 subo 8,g2,g2 # Decrement len 103 lda 8(g6),g6 # Increment dest_ptr 104 bl.t Lwloop # loop if more longwords to store 105 106Lcloop_setup: 107 cmpobge.t 0,g2,Lexit 108 109Lcloop: 110 cmpo 1,g2 # Is len exhausted? 111 stob g1,(g6) # Store byte 112 subo 1,g2,g2 # Decrement len 113 lda 1(g6),g6 # Increment dest_ptr 114 bne.t Lcloop # loop if more bytes to store 115 116Lexit: 117 bx (g13) 118Lrett: 119 ret 120 121/* end of memset */ 122