| /* |
| * (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: 1.1 $ */ |
| /* |
| * 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) |
