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122 lines
3.9 KiB
ArmAsm
122 lines
3.9 KiB
ArmAsm
/*******************************************************************************
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*
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* Copyright (c) 1993 Intel Corporation
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*
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* Intel hereby grants you permission to copy, modify, and distribute this
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* software and its documentation. Intel grants this permission provided
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* that the above copyright notice appears in all copies and that both the
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* copyright notice and this permission notice appear in supporting
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* documentation. In addition, Intel grants this permission provided that
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* you prominently mark as "not part of the original" any modifications
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* made to this software or documentation, and that the name of Intel
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* Corporation not be used in advertising or publicity pertaining to
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* distribution of the software or the documentation without specific,
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* written prior permission.
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*
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* Intel Corporation provides this AS IS, WITHOUT ANY WARRANTY, EXPRESS OR
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* IMPLIED, INCLUDING, WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY
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* OR FITNESS FOR A PARTICULAR PURPOSE. Intel makes no guarantee or
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* representations regarding the use of, or the results of the use of,
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* the software and documentation in terms of correctness, accuracy,
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* reliability, currentness, or otherwise; and you rely on the software,
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* documentation and results solely at your own risk.
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*
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* IN NO EVENT SHALL INTEL BE LIABLE FOR ANY LOSS OF USE, LOSS OF BUSINESS,
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* LOSS OF PROFITS, INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES
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* OF ANY KIND. IN NO EVENT SHALL INTEL'S TOTAL LIABILITY EXCEED THE SUM
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* PAID TO INTEL FOR THE PRODUCT LICENSED HEREUNDER.
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*
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******************************************************************************/
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.file "memset.s"
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#ifdef __PIC
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.pic
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#endif
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#ifdef __PID
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.pid
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#endif
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/*
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* (c) copyright 1989,1993 Intel Corp., all rights reserved
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*/
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/*
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procedure memset (optimized assembler version: 80960K series, 80960CA)
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dest_addr = memset (dest_addr, char, len)
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Fill len bytes pointed to by dest_addr with the value of char.
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Return the original address of dest_addr.
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This program avoids performing unaligned accesses. It stores
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from zero to seven bytes, and then stores aligned longwords,
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and then stores from zero to seven bytes, as necessary to
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store len bytes starting at dest_addr.
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At the time of this writing, only g0 thru g7 and g13 are available
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for use in this leafproc; other registers would have to be saved and
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restored. These nine registers, plus tricky use of g14 are sufficient
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to implement the routine.
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*/
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.globl _memset
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.globl __memset
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.leafproc _memset, __memset
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.align 2
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_memset:
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#ifndef __PIC
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lda Lrett,g14
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#else
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lda Lrett-(.+8)(ip),g14
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#endif
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__memset:
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cmpo 7,g2 # are there fewer than seven characters to move?
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lda (g14),g13 # save return address
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notand g0,7,g3 # test for non-aligned dest_ptr
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lda 0,g14 # conform to register conventions
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shlo 24,g1,g4 # prepare word of char
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lda (g0),g6 # preserve dest_ptr for return
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shro 8,g4,g5
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bge.f Lcloop_setup
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cmpo g3,g0 # is dest longword aligned
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lda 7(g3),g3 # bump dest_ptr to next longword boundary
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or g4,g5,g4
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be.t Lwloop_setup
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Lbgn_cloop:
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cmpo g6,g3 # Have we reached longword boundary?
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stob g1,(g6) # store one byte of char
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subo 1,g2,g2 # decrement len
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lda 1(g6),g6 # increment dest_ptr
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bne.t Lbgn_cloop # loop if more bytes to store before longword
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cmpobge.f 7,g2,Lcloop
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Lwloop_setup:
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shro 16,g4,g5
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or g4,g5,g4
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mov g4,g5 # now have a longword of char
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Lwloop:
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cmpo 15,g2 # Do we have to store more longwords?
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stl g4,(g6) # Store longword of char
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subo 8,g2,g2 # Decrement len
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lda 8(g6),g6 # Increment dest_ptr
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bl.t Lwloop # loop if more longwords to store
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Lcloop_setup:
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cmpobge.t 0,g2,Lexit
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Lcloop:
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cmpo 1,g2 # Is len exhausted?
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stob g1,(g6) # Store byte
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subo 1,g2,g2 # Decrement len
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lda 1(g6),g6 # Increment dest_ptr
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bne.t Lcloop # loop if more bytes to store
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Lexit:
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bx (g13)
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Lrett:
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ret
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/* end of memset */
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