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/*******************************************************************************
 * 
 * Copyright (c) 1993 Intel Corporation
 * 
 * Intel hereby grants you permission to copy, modify, and distribute this
 * software and its documentation.  Intel grants this permission provided
 * that the above copyright notice appears in all copies and that both the
 * copyright notice and this permission notice appear in supporting
 * documentation.  In addition, Intel grants this permission provided that
 * you prominently mark as "not part of the original" any modifications
 * made to this software or documentation, and that the name of Intel
 * Corporation not be used in advertising or publicity pertaining to
 * distribution of the software or the documentation without specific,
 * written prior permission.
 * 
 * Intel Corporation provides this AS IS, WITHOUT ANY WARRANTY, EXPRESS OR
 * IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY
 * OR FITNESS FOR A PARTICULAR PURPOSE.  Intel makes no guarantee or
 * representations regarding the use of, or the results of the use of,
 * the software and documentation in terms of correctness, accuracy,
 * reliability, currentness, or otherwise; and you rely on the software,
 * documentation and results solely at your own risk.
 *
 * IN NO EVENT SHALL INTEL BE LIABLE FOR ANY LOSS OF USE, LOSS OF BUSINESS,
 * LOSS OF PROFITS, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES
 * OF ANY KIND.  IN NO EVENT SHALL INTEL'S TOTAL LIABILITY EXCEED THE SUM
 * PAID TO INTEL FOR THE PRODUCT LICENSED HEREUNDER.
 * 
 ******************************************************************************/

        .file "memset.s"
#ifdef  __PIC
        .pic
#endif
#ifdef  __PID
        .pid
#endif
/*
 * (c) copyright 1989,1993 Intel Corp., all rights reserved
 */

/*
        procedure memset  (optimized assembler version: 80960K series, 80960CA)

        dest_addr = memset (dest_addr, char, len)

        Fill len bytes pointed to by dest_addr with the value of char.
        Return the original address of dest_addr.

        This program avoids performing unaligned accesses.  It stores
        from zero to seven bytes, and then stores aligned longwords,
        and then stores from zero to seven bytes, as necessary to
        store len bytes starting at dest_addr.

        At the time of this writing, only g0 thru g7 and g13 are available 
        for use in this leafproc;  other registers would have to be saved and
        restored.  These nine registers, plus tricky use of g14 are sufficient
        to implement the routine.
*/

        .globl  _memset
        .globl  __memset
        .leafproc       _memset, __memset
        .align  2
_memset:
#ifndef __PIC
        lda     Lrett,g14
#else
        lda     Lrett-(.+8)(ip),g14
#endif
__memset:
        cmpo    7,g2            # are there fewer than seven characters to move?
         lda    (g14),g13       # save return address
        notand  g0,7,g3         # test for non-aligned dest_ptr
         lda    0,g14           # conform to register conventions
        shlo    24,g1,g4        # prepare word of char
         lda    (g0),g6         # preserve dest_ptr for return
        shro    8,g4,g5
         bge.f  Lcloop_setup
        cmpo    g3,g0           # is dest longword aligned
         lda    7(g3),g3        # bump dest_ptr to next longword boundary
        or      g4,g5,g4
         be.t   Lwloop_setup

Lbgn_cloop:
        cmpo    g6,g3           # Have we reached longword boundary?
         stob   g1,(g6)         # store one byte of char
        subo    1,g2,g2         # decrement len
         lda    1(g6),g6        # increment dest_ptr
        bne.t   Lbgn_cloop      # loop if more bytes to store before longword

        cmpobge.f 7,g2,Lcloop

Lwloop_setup:
        shro    16,g4,g5
        or      g4,g5,g4
        mov     g4,g5           # now have a longword of char

Lwloop:
        cmpo    15,g2           # Do we have to store more longwords?
         stl    g4,(g6)         # Store longword of char
        subo    8,g2,g2         # Decrement len
         lda    8(g6),g6        # Increment dest_ptr
        bl.t    Lwloop          # loop if more longwords to store

Lcloop_setup:
        cmpobge.t 0,g2,Lexit

Lcloop:
        cmpo    1,g2            # Is len exhausted?
         stob   g1,(g6)         # Store byte
        subo    1,g2,g2         # Decrement len
         lda    1(g6),g6        # Increment dest_ptr
        bne.t   Lcloop          # loop if more bytes to store

Lexit:  
        bx      (g13)
Lrett:  
        ret

/* end of memset */