| /* |
| * (c) Copyright 1986 HEWLETT-PACKARD COMPANY |
| * |
| * To anyone who acknowledges that this file is provided "AS IS" |
| * without any express or implied warranty: |
| * permission to use, copy, modify, and distribute this file |
| * for any purpose is hereby granted without fee, provided that |
| * the above copyright notice and this notice appears in all |
| * copies, and that the name of Hewlett-Packard Company not be |
| * used in advertising or publicity pertaining to distribution |
| * of the software without specific, written prior permission. |
| * Hewlett-Packard Company makes no representations about the |
| * suitability of this software for any purpose. |
| */ |
| |
| /* SPECTRUM_ID: @(#)memset.s 37.4 86/08/25 */ |
| /* |
| * memset(s, c, n) |
| * |
| * Sets first n chars in memory area s to value of character c. |
| * Returns s. |
| */ |
| #ifndef _NAMESPACE_CLEAN |
| #define NOSECDEF /* prevent _memset from being defined as entry */ |
| #endif |
| |
| #include "DEFS.h" |
| |
| #define TO arg0 |
| #define FILLCHAR arg1 |
| #define COUNT arg2 |
| #define TMP r31 |
| |
| ENTRY(memset) |
| comb,<= COUNT,r0,msexit /* return if count not positive */ |
| copy TO,ret0 /* return value is start of copy */ |
| comibf,<,n 5,COUNT,msbyteloop /* be straightforward */ |
| |
| dep FILLCHAR,23,8,FILLCHAR /* dup low byte */ |
| dep FILLCHAR,15,16,FILLCHAR /* into high bytes */ |
| |
| add TO,COUNT,TMP /* TMP points just past fill area */ |
| stbys,m FILLCHAR,0(TO) /* fill out first word */ |
| /* |
| * If we're pointing to high-order byte, no fill will happen, |
| * but permissions will be checked. We don't want this (we |
| * might be pointing at the beginning of a protected region), |
| * so we branch around stbys if neither low bits are set. |
| */ |
| bb,<,n TMP,31,filend /* if low bit is set, stbys */ |
| bb,>=,n TMP,30,endfil /* if next lowest bit isn't set */ |
| /* (and lowest isn't, either) */ |
| /* do not stbys */ |
| filend: |
| stbys,m,e FILLCHAR,0(TMP) /* fill out the last */ |
| endfil: |
| addi 4, TO, TO |
| sub TMP,TO,COUNT /* will now divide by 4 */ |
| comb,=,n COUNT,r0,msexit /* If count is zero ret. */ |
| |
| extru,<> COUNT,31,4,r1 |
| b msquadloop |
| depi 0,31,4,COUNT /* will now divide by 16 */ |
| |
| |
| mswordloop: |
| addib,<> -4,r1,mswordloop |
| stws,ma FILLCHAR,4(TO) |
| |
| comb,=,n COUNT,r0,msexit /* If count is zero ret. */ |
| |
| msquadloop: |
| stws,ma FILLCHAR,4(TO) |
| stws,ma FILLCHAR,4(TO) |
| stws,ma FILLCHAR,4(TO) |
| addib,<> -16,COUNT,msquadloop |
| stws,ma FILLCHAR,4(TO) |
| b,n msexit |
| |
| msbyteloop: |
| addib,<> -1,COUNT,msbyteloop |
| stbs,ma FILLCHAR,1(TO) |
| |
| msexit: |
| EXIT(memset) |
