mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-28 05:51:04 +00:00
286 lines
10 KiB
ArmAsm
286 lines
10 KiB
ArmAsm
/*
|
|
* (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.
|
|
*/
|
|
|
|
/*
|
|
A faster strcpy.
|
|
|
|
by
|
|
|
|
Jerry Huck (aligned case)
|
|
Daryl Odnert (equal-alignment case)
|
|
Edgar Circenis (non-aligned case)
|
|
*/
|
|
/*
|
|
* strcpy(s1, s2)
|
|
*
|
|
* Copy string s2 to s1. s1 must be large enough.
|
|
* return s1
|
|
*/
|
|
|
|
#include "DEFS.h"
|
|
|
|
#define d_addr r26
|
|
#define s_addr r25
|
|
#define tmp6 r24
|
|
#define tmp1 r19
|
|
#define evenside r19
|
|
#define tmp2 r20
|
|
#define oddside r20
|
|
#define tmp3 r21
|
|
#define tmp4 r22
|
|
#define tmp5 arg3
|
|
#define save r1
|
|
|
|
|
|
ENTRY(strcpy)
|
|
/* Do some quick alignment checking on and fast path both word aligned */
|
|
extru,<> s_addr,31,2,tmp6 /*Is source word aligned? */
|
|
ldwm 4(0,s_addr),oddside /*Assume yes and guess that it
|
|
is double-word aligned. */
|
|
dep,= d_addr,29,2,tmp6 /*Is target word aligned? */
|
|
b case_analysis
|
|
copy d_addr,ret0
|
|
/* Both are aligned. First source word already loaded assuming that
|
|
source was oddword aligned. Fall through (therefore fastest) code
|
|
shuffles the registers to join the main loop */
|
|
bothaligned:
|
|
bb,>= s_addr,29,twoatatime /*Branch if source was odd aligned*/
|
|
uxor,nbz oddside,r0,save
|
|
|
|
/* Even aligned source. save holds that operand.
|
|
Do one iteration of the main copy loop juggling the registers to avoid
|
|
one copy. */
|
|
b,n nullfound
|
|
ldwm 4(s_addr),oddside
|
|
stwm save,4(d_addr)
|
|
uxor,nbz oddside,r0,save
|
|
b,n nullfound
|
|
ldwm 4(s_addr),evenside
|
|
stwm oddside,4(d_addr)
|
|
uxor,nbz evenside,r0,save
|
|
b,n nullfound
|
|
ldwm 4(s_addr),oddside
|
|
|
|
/* Main loop body. Entry expects evenside still to be stored, oddside
|
|
just loaded. */
|
|
loop:
|
|
stwm evenside,4(d_addr)
|
|
uxor,nbz oddside,r0,save
|
|
|
|
/* mid loop entry */
|
|
twoatatime:
|
|
b,n nullfound
|
|
ldwm 4(s_addr),evenside
|
|
stwm oddside,4(d_addr)
|
|
uxor,sbz evenside,r0,save
|
|
b loop
|
|
ldwm 4(s_addr),oddside
|
|
|
|
/* fall through when null found in evenside. oddside actually loaded */
|
|
nullfound: /* adjust d_addr and store final word */
|
|
|
|
extru,<> save,7,8,r0 /* pick up leftmost byte */
|
|
addib,tr,n 1,d_addr,store_final
|
|
extru,<> save,15,8,r0
|
|
addib,tr,n 2,d_addr,store_final
|
|
extru,<> save,23,8,r0
|
|
addib,tr 3,d_addr,store_final2
|
|
bv 0(rp)
|
|
stw save,0(d_addr)
|
|
|
|
store_final:
|
|
bv 0(rp)
|
|
store_final2:
|
|
stbys,e save,0(d_addr) /* delay slot */
|
|
|
|
case_analysis:
|
|
|
|
blr tmp6,r0
|
|
nop
|
|
|
|
/* NOTE: the delay slots for the non-aligned cases load a */
|
|
/* shift quantity which is TGT-SRC into tmp3. */
|
|
/* Note also, the case for both strings being word aligned */
|
|
/* is already checked before the BLR is executed, so that */
|
|
/* case can never occur. */
|
|
|
|
/* TGT SRC */
|
|
nop /* 00 00 can't happen */
|
|
nop
|
|
b neg_aligned_copy /* 00 01 */
|
|
ldi -1,tmp3 /* load shift quantity. delay slot */
|
|
b neg_aligned_copy /* 00 10 */
|
|
ldi -2,tmp3 /* load shift quantity. delay slot */
|
|
b neg_aligned_copy /* 00 11 */
|
|
ldi -3,tmp3 /* load shift quantity. delay slot */
|
|
b pos_aligned_copy0 /* 01 00 */
|
|
ldi 1,tmp3 /* load shift quantity. delay slot */
|
|
b equal_alignment_1 /* 01 01 */
|
|
ldbs,ma 1(s_addr),tmp1
|
|
b neg_aligned_copy /* 01 10 */
|
|
ldi -1,tmp3 /* load shift quantity. delay slot */
|
|
b neg_aligned_copy /* 01 11 */
|
|
ldi -2,tmp3 /* load shift quantity. delay slot */
|
|
b pos_aligned_copy0 /* 10 00 */
|
|
ldi 2,tmp3 /* load shift quantity. delay slot */
|
|
b pos_aligned_copy /* 10 01 */
|
|
ldi 1,tmp3 /* load shift quantity. delay slot */
|
|
b equal_alignment_2 /* 10 10 */
|
|
ldhs,ma 2(s_addr),tmp1
|
|
b neg_aligned_copy /* 10 11 */
|
|
ldi -1,tmp3 /* load shift quantity. delay slot */
|
|
b pos_aligned_copy0 /* 11 00 */
|
|
ldi 3,tmp3 /* load shift quantity. delay slot */
|
|
b pos_aligned_copy /* 11 01 */
|
|
ldi 2,tmp3 /* load shift quantity. delay slot */
|
|
b pos_aligned_copy /* 11 10 */
|
|
ldi 1,tmp3 /* load shift quantity. delay slot */
|
|
ldbs,ma 1(s_addr),tmp1 /* 11 11 */
|
|
comiclr,<> r0,tmp1,r0
|
|
bv 0(rp) /* return if 1st byte was null */
|
|
stbs,ma tmp1,1(d_addr) /* store a byte to dst string */
|
|
b bothaligned /* can now goto word_aligned */
|
|
ldwm 4(s_addr),oddside /* load next word of source */
|
|
|
|
equal_alignment_1:
|
|
comiclr,<> r0,tmp1,r0 /* nullify next if tmp1 <> 0 */
|
|
bv 0(rp) /* return if null byte found */
|
|
stbs,ma tmp1,1(d_addr) /* store a byte to dst string */
|
|
ldhs,ma 2(s_addr),tmp1 /* load next halfword */
|
|
equal_alignment_2:
|
|
extru,<> tmp1,23,8,tmp6 /* look at left byte of halfword */
|
|
bv 0(rp) /* return if 1st byte was null */
|
|
stbs,ma tmp6,1(d_addr)
|
|
extru,<> tmp1,31,8,r0
|
|
bv 0(rp) /* return if 2nd byte was null */
|
|
stbs,ma tmp1,1(d_addr)
|
|
b bothaligned
|
|
ldwm 4(s_addr),oddside /* load next word */
|
|
|
|
/* source and destination are not aligned, so we do it the hard way. */
|
|
|
|
/* target alignment is greater than source alignment */
|
|
pos_aligned_copy0:
|
|
addi -4,s_addr,s_addr
|
|
pos_aligned_copy:
|
|
extru d_addr,31,2,tmp6 /* Extract low 2 bits of the dest addr */
|
|
extru s_addr,31,2,tmp1 /* Extract low 2 bits of the src addr */
|
|
dep r0,31,2,s_addr /* Compute word address of the source. */
|
|
sh3add tmp3,r0,tmp4 /* compute shift amt */
|
|
ldwm 4(0,s_addr),tmp2 /* get 1st source word */
|
|
sh3add tmp1,r0,save /* setup mask shift amount */
|
|
mtctl save,r11 /* set-up cr11 for mask */
|
|
zvdepi -2,32,save /* create mask */
|
|
or save,tmp2,tmp2 /* mask unused bytes in src */
|
|
ldi -1,tmp1 /* load tmp1 with 0xffffffff */
|
|
mtctl tmp4,r11 /* shift count -> shift count reg */
|
|
vshd tmp1,tmp2,tmp3 /* position data ! */
|
|
uxor,nbz tmp3,r0,save
|
|
b,n first_null
|
|
uxor,nbz tmp2,r0,save
|
|
b nullfound1
|
|
mtctl tmp4,r11 /* re-load shift cnt (delay slot) */
|
|
b loop_entry
|
|
ldwm 4(0,s_addr),tmp1 /* get next word. delay slot */
|
|
|
|
neg_aligned_copy:
|
|
extru d_addr,31,2,tmp6 /* Extract low 2 bits of the dest addr */
|
|
extru s_addr,31,2,tmp2 /* Extract low 2 bits of the src addr */
|
|
dep r0,31,2,s_addr /* Compute word address of the source. */
|
|
sh3add tmp3,r0,tmp4 /* compute shift amt */
|
|
ldwm 4(0,s_addr),tmp1 /* load first word from source. */
|
|
/* check to see if next word can be read safely */
|
|
sh3add tmp2,r0,save
|
|
mtctl save,r11 /* shift count -> shift count reg */
|
|
zvdepi -2,32,save
|
|
or save, tmp1, tmp1
|
|
uxor,nbz tmp1,r0,save /* any nulls in first word? */
|
|
b first_null0
|
|
mtctl tmp4,r11
|
|
ldwm 4(0,s_addr),tmp2 /* load second word from source */
|
|
combt,= tmp6,r0,chunk1 /* don't mask if whole word valid */
|
|
vshd tmp1,tmp2,tmp3 /* position data ! */
|
|
sh3add tmp6,r0,save /* setup r1 */
|
|
mtctl save,r11 /* set-up cr11 for mask */
|
|
zvdepi -2,32,save
|
|
or save, tmp3, tmp3
|
|
uxor,nbz tmp3,r0,save
|
|
b,n first_null
|
|
uxor,nbz tmp2,r0,save
|
|
b nullfound1
|
|
mtctl tmp4,r11 /* re-load shift cnt (delay slot) */
|
|
b loop_entry
|
|
ldwm 4(0,s_addr),tmp1 /* get next word. delay slot */
|
|
|
|
chunk1:
|
|
uxor,nbz tmp2,r0,save
|
|
b nullfound0
|
|
vshd tmp1,tmp2,tmp3
|
|
did_mask:
|
|
ldwm 4(0,s_addr),tmp1 /* get next word ! */
|
|
loop_entry:
|
|
stbys,b,m tmp3,4(0,d_addr) /* store ! */
|
|
|
|
uxor,nbz tmp1, r0, save
|
|
b nullfound2
|
|
vshd tmp2,tmp1,tmp3 /* position data ! */
|
|
ldwm 4(s_addr),tmp2
|
|
stwm tmp3,4(d_addr)
|
|
uxor,sbz tmp2,r0,save
|
|
b did_mask
|
|
nullfound0:
|
|
vshd tmp1,tmp2,tmp3 /* delay slot */
|
|
uxor,nbz tmp3,r0,save
|
|
b,n nullfound
|
|
nullfound1:
|
|
stbys,b,m tmp3,4(0,d_addr)
|
|
b nullfound
|
|
vshd tmp2,r0,save /* delay slot */
|
|
|
|
nullfound2:
|
|
uxor,nbz tmp3,r0,save
|
|
b,n nullfound
|
|
stwm tmp3,4(d_addr)
|
|
b nullfound
|
|
/* notice that delay slot is in next routine */
|
|
|
|
first_null0: /* null found in first word of non-aligned (wrt d_addr) */
|
|
vshd tmp1,r0,save /* delay slot */
|
|
combt,= tmp6,r0,check4
|
|
extru save,7,8,tmp4
|
|
first_null:
|
|
addibt,= -1,tmp6,check3 /* check last 3 bytes of word */
|
|
extru save,15,8,tmp4
|
|
addibt,=,n -1,tmp6,check2 /* check last 2 bytes */
|
|
bv 0(rp) /* null in last byte--store and exit */
|
|
stbys,b save, 0(d_addr)
|
|
|
|
check4:
|
|
combt,= tmp4,r0,done
|
|
stbs,ma tmp4,1(d_addr)
|
|
extru,<> save,15,8,tmp4
|
|
check3:
|
|
combt,= tmp4,r0,done
|
|
stbs,ma tmp4,1(d_addr)
|
|
check2:
|
|
extru,<> save,23,8,tmp4
|
|
bv 0(rp)
|
|
stbs,ma tmp4,1(d_addr)
|
|
bv 0(rp)
|
|
stbs r0,0(d_addr)
|
|
|
|
done:
|
|
EXIT(strcpy)
|