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acadia-newlib/newlib/libc/machine/hppa/strncpy.S

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/*
* (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.
*/
/* HPUX_ID: @(#) $Revision$ */
/*
* strncpy(s1, s2, n)
*
* Copy s2 to s1, truncating or null-padding to always copy n bytes
* return s1
*/
#include "DEFS.h"
#define d_addr r26
#define s_addr r25
#define count r24
#define tmp1 r19
#define tmp2 r20
#define tmp3 r21
#define tmp4 r22
#define tmp5 arg3
#define save r1
ENTRY(strncpy)
combt,= s_addr,r0,pad_null_bytes1 /* if s2==NULL then pad nulls and exit */
copy d_addr,ret0 /* The return value is defined to be the value of d_addr. DELAY SLOT*/
addibt,<,n -4,count,byteloop /* If count is <= 4 don't get fancy.*/
extru s_addr,31,2,tmp1 /* Extract the low two bits of the source address.*/
extru d_addr,31,2,tmp5 /* Extract the low two bits of the destination address.*/
add count,tmp5,count /* pre increment the count by the byte address so that the count is*/
comb,<> tmp5,tmp1,not_aligned /* branch if tmp5<>tmp1. */
dep 0,31,2,s_addr /* Compute the word address of the source. DELAY SLOT.*/
/* aligned*/
combt,= tmp5,r0,skip_mask
ldwm 4(0,s_addr),tmp1 /* tmp1 = *s_addr s_addr += 4 (DELAY SLOT)*/
sh3add tmp5,r0,save /* compute mask in save*/
mtctl save,11
zvdepi -2,32,save
b skip_mask /* don't reload tmp1*/
or save,tmp1,tmp1 /* or mask with data*/
chunks:
ldwm 4(0,s_addr),tmp1 /* get a word*/
skip_mask:
uxor,nbz tmp1,r0,save /* check for null*/
b,n null1
addibf,< -4,count,chunks
stbys,b,m tmp1,4(0,d_addr) /* store word (delay slot)*/
/* back_porch last word to store*/
addibt,=,n 4,count,done /* if count = 0 we're, of course, done !*/
ldws 0(s_addr),tmp1 /* load up the back_porch*/
add d_addr,count,d_addr/* final store address is +1 too high !*/
sh3add count,r0, save /* setup right mask based on count*/
mtctl save,r11
zvdepi -2,32,save /*save now has left-hand mask*/
uaddcm r0,save,save /*form right hand mask */
or tmp1,save,tmp1 /*and insert data*/
uxor,nbz tmp1,r0,save /* check for null*/
b,n null2
bv 0(r2)
stbys,e tmp1,0(d_addr) /* done */
/* Begin non_aligned code. */
not_aligned:
sub,>= tmp5,tmp1,tmp3 /* compute the shift amt.and skip load if tmp5 > tmp1.*/
ldwm 4(0,s_addr),tmp1 /* load up the first word from the source. tmp1 = *s_addr++*/
zdep tmp3,28,29,tmp4 /* compute the number of bits to shift */
mtctl tmp4,11 /* load the shift count into cr11 = shift count register.*/
addibt,<,n -4,count,chkchnk2 /* first step in pre adjustment of count for looping.*/
ldwm 4(0,s_addr),tmp2 /* get either first or second word from source. */
combt,= tmp5,r0,skip_mask2 /* don't mask if whole word is valid*/
vshd tmp1,tmp2,tmp3 /* position data ! (delay slot)*/
sh3add tmp5,r0,save /* setup r1*/
mtctl save,r11 /* setup mask in save*/
zvdepi -2,32,save
or save, tmp3, tmp3
mtctl tmp4,11 /* re-load the shift count into cr11 */
b skip_mask2
copy r0, tmp5 /* zero out tmp5 so we don't try to mask again*/
chunk2:
ldwm 4(0,s_addr),tmp2
vshd tmp1,tmp2,tmp3
skip_mask2:
uxor,nbz tmp3, r0, save
b,n null3
stbys,b,m tmp3,4(0,d_addr) /* store ! */
ldwm 4(0,s_addr),tmp1 /* get 2nd word ! */
vshd tmp2,tmp1,tmp3 /* position data ! */
uxor,nbz tmp3, r0, save
b,n null4
addibf,< -8,count,chunk2 /* If count is still >= 8 do another loop.*/
stbys,b,m tmp3,4(0,d_addr) /* store !*/
chkchnk2:
addibt,<,n 4,count,bp_0 /* if we don't have 4 bytes left then do the back porch (bp_0)*/
subchnk2: /* we have less than 8 chars to copy*/
ldwm 4(0,s_addr),tmp2 /* get next word !*/
combt,= tmp5,r0,skip_mask3
vshd tmp1,tmp2,tmp3 /* position data !*/
sh3add tmp5,r0,save /* setup r1*/
mtctl save,r11 /* setup mask in save*/
zvdepi -2,32,save
or save, tmp3, tmp3
mtctl tmp4,11 /* restore shift value again */
copy r0, tmp5 /* zero out tmp5 so we don't try to mask again*/
skip_mask3:
uxor,nbz tmp3,r0,save
b,n null4
b bp_1 /* we now have less than 4 bytes to move*/
stbys,b,m tmp3,4(0,d_addr) /* store !*/
bp_0:
copy tmp1,tmp2 /* switch registers used in the shift process.*/
addibt,<=,n 4,count,done /* if count = -4 this implies that count = 0 -> done */
bp_1:
ldwm 4(0,s_addr),tmp1 /* get final word ! */
vshd tmp2,tmp1,tmp3 /* position data !*/
uxor,sbz tmp3,r0,save /* if some-byte-zero */
b no_null /* don't goto no_null-find which null instead */
add d_addr,count,d_addr /* get d_addr ready for stbys,e */
extru,<> save,7,8,r0
b found_null5
copy r0, tmp5
extru,<> save,15,8,r0
b found_null5
ldil 0x1FE000,tmp5 /* setup mask (FF000000)*/
extru,<> save,23,8,r0
b found_null5
ldil 0x1FFFE0,tmp5 /* setup mask (FFFF0000)*/
ldo -1(r0),tmp5 /* setup mask (FFFFFFFF)*/
found_null5:
and tmp3,tmp5,tmp3 /* zero out tmp5 based on mask in tmp5*/
no_null:
bv 0(r2) /* were done*/
stbys,e tmp3,0(0,d_addr) /* store the data !*/
/* here we do ye old byte-at-a-time moves.*/
byteloop:
addibt,=,n 4,count,done
comb,= 0,s_addr,done
stbs r0,0(d_addr) /* store null in case s_addr == NULL */
ldbs,ma 1(s_addr),tmp1
encore:
combt,=,n tmp1,r0, pad_null_bytes1
stbs,ma tmp1,1(d_addr)
addibf,=,n -1,count,encore
ldbs,ma 1(s_addr),tmp1
b,n done
pnb_1:
addibt,=,n 4,count,done /* if count was already 0 then we're done*/
pad_null_bytes1:
combt,=,n count,r0,done /* if count==0 then exit */
pad_null_bytes2:
addibf,= -1,count,pad_null_bytes2
stbs,ma r0,1(d_addr)
b,n done
pad_nulls:
addibf,<=,n -4,count,pad_nulls
stwm r0,4(d_addr)
b,n pnb_1
null1:
extru,<> save,7,8,r0
b found_null1
copy r0, tmp5
extru,<> save,15,8,r0
b found_null1
ldil 0x1FE000,tmp5 /* setup mask (FF000000)*/
extru,<> save,23,8,r0
b found_null1
ldil 0x1FFFE0,tmp5 /* setup mask (FFFF0000)*/
ldo -1(r0),tmp5 /* setup mask (FFFFFFFF)*/
found_null1:
and tmp1,tmp5,tmp1 /*zero out tmp1 according to mask*/
b pad_nulls /* nullify remaining count bytes*/
stbys,b,m tmp1,4(0,d_addr) /* first word (account for alignment)*/
null2: /* back porch case. We have less than 4 bytes to go.*/
extru,<> save,7,8,r0 /* is null in 1st byte? */
b found_null2
copy r0, tmp5
extru,<> save,15,8,r0 /* is null in 2nd byte? */
b found_null2
ldil 0x1FE000,tmp5 /* setup mask (FF000000)*/
b found_null2 /* null must be in 3rd byte */
ldil 0x1FFFE0,tmp5 /* setup mask (FFFF0000)*/
found_null2:
and tmp1,tmp5,tmp1 /*zero out tmp1 according to mask*/
bv 0(r2) /* we're done*/
stbys,e tmp1,0(0,d_addr) /* last word (back porch)*/
null3: /* not_aligned case where null is found in first of two words--adjust count*/
extru,<> save,7,8,r0
b found_null3
copy r0, tmp5
extru,<> save,15,8,r0
b found_null3
ldil 0x1FE000,tmp5 /* setup mask (FF000000)*/
extru,<> save,23,8,r0
b found_null3
ldil 0x1FFFE0,tmp5 /* setup mask (FFFF0000)*/
ldo -1(r0),tmp5 /* setup mask (FFFFFFFF)*/
found_null3:
addi 4,count,count /* fix count since null is in first of two words*/
and tmp3,tmp5,tmp3 /*zero out tmp3 according to mask*/
b pad_nulls /* nullify remaining count bytes*/
stbys,b,m tmp3,4(d_addr)
null4: /* not_aligned case where null is found in second of two words*/
extru,<> save,7,8,r0
b found_null4
copy r0, tmp5
extru,<> save,15,8,r0
b found_null4
ldil 0x1FE000,tmp5 /* setup mask (FF000000)*/
extru,<> save,23,8,r0
b found_null4
ldil 0x1FFFE0,tmp5 /* setup mask (FFFF0000)*/
ldo -1(r0),tmp5 /* setup mask (FFFFFFFF)*/
found_null4:
and tmp3,tmp5,tmp3 /*zero out tmp4 according to mask*/
b pad_nulls /* nullify remaining count bytes*/
stbys,b,m tmp3,4(d_addr)
done:
EXIT(strncpy)
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