projects / unix-history / blame
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|---|---|---|
| 586c39b1 DF |
1 | /* |
| 2 | * Copyright (c) 1983 Regents of the University of California. | |
| 493b70ca KB |
3 | * All rights reserved. |
| 4 | * | |
| 5 | * Redistribution and use in source and binary forms are permitted | |
| f4f66d2c KB |
6 | * provided that the above copyright notice and this paragraph are |
| 7 | * duplicated in all such forms and that any documentation, | |
| 8 | * advertising materials, and other materials related to such | |
| 9 | * distribution and use acknowledge that the software was developed | |
| 10 | * by the University of California, Berkeley. The name of the | |
| 11 | * University may not be used to endorse or promote products derived | |
| 12 | * from this software without specific prior written permission. | |
| 13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR | |
| 14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED | |
| 15 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. | |
| 586c39b1 DF |
16 | */ |
| 17 | ||
| f4f66d2c KB |
18 | #if defined(LIBC_SCCS) && !defined(lint) |
| 19 | .asciz "@(#)rindex.s 5.5 (Berkeley) %G%" | |
| 20 | #endif /* LIBC_SCCS and not lint */ | |
| a01b1b6c SL |
21 | |
| 22 | /* | |
| 23 | * Find the last occurence of c in the string cp. | |
| 24 | * Return pointer to match or null pointer. | |
| 25 | * | |
| 26 | * char * | |
| 27 | * rindex(cp, c) | |
| 28 | * char *cp, c; | |
| 29 | */ | |
| dadab5a2 | 30 | #include "DEFS.h" |
| a01b1b6c | 31 | |
| dadab5a2 | 32 | ENTRY(rindex, 0) |
| a01b1b6c SL |
33 | movq 4(ap),r1 # r1 = cp; r2 = c |
| 34 | tstl r2 # check for special case c == '\0' | |
| 35 | bneq 2f | |
| 36 | 1: | |
| 37 | locc $0,$65535,(r1) # just find end of string | |
| 38 | beql 1b # still looking | |
| 39 | movl r1,r0 # found it | |
| 40 | ret | |
| 41 | 2: | |
| 8f899db2 KM |
42 | moval tbl,r3 # r3 = address of table |
| 43 | bbss $0,(r3),5f # insure not reentering | |
| 44 | movab (r3)[r2],r5 # table entry for c | |
| a01b1b6c SL |
45 | incb (r5) |
| 46 | clrl r4 # last found | |
| 47 | 3: | |
| 8f899db2 | 48 | scanc $65535,(r1),(r3),$1 # look for c or '\0' |
| a01b1b6c SL |
49 | beql 3b # keep looking |
| 50 | tstb (r1) # if have found '\0' | |
| 51 | beql 4f # we are done | |
| 52 | movl r1,r4 # save most recently found | |
| 53 | incl r1 # skip over character | |
| 54 | jbr 3b # keep looking | |
| 55 | 4: | |
| 56 | movl r4,r0 # return last found (if any) | |
| 57 | clrb (r5) # clean up table | |
| 8f899db2 | 58 | clrb (r3) |
| a01b1b6c SL |
59 | ret |
| 60 | ||
| 61 | .data | |
| 8f899db2 | 62 | tbl: .space 256 |
| a01b1b6c | 63 | .text |
| 8f899db2 KM |
64 | |
| 65 | /* | |
| 66 | * Reentrant, but slower version of rindex | |
| 67 | */ | |
| 68 | 5: | |
| 69 | movl r1,r3 | |
| 70 | clrl r4 # r4 = pointer to last match | |
| 71 | 6: | |
| 72 | locc $0,$65535,(r3) # look for '\0' | |
| 73 | bneq 8f | |
| 74 | decw r0 # r0 = 65535 | |
| 75 | 1: | |
| 76 | locc r2,r0,(r3) # look for c | |
| 77 | bneq 7f | |
| 78 | movl r1,r3 # reset pointer and ... | |
| 79 | jbr 6b # ... try again | |
| 80 | 7: | |
| 81 | movl r1,r4 # stash pointer ... | |
| 82 | addl3 $1,r1,r3 # ... skip over match and ... | |
| 83 | decl r0 # ... decrement count | |
| 84 | jbr 6b # ... try again | |
| 85 | 8: | |
| 86 | subl3 r3,r1,r0 # length of short block | |
| 87 | incl r0 # +1 for '\0' | |
| 88 | 9: | |
| 89 | locc r2,r0,(r3) # look for c | |
| 90 | beql 0f | |
| 91 | movl r1,r4 # stash pointer ... | |
| 92 | addl3 $1,r1,r3 # ... skip over match ... | |
| 93 | decl r0 # ... adjust count and ... | |
| 94 | jbr 9b # ... try again | |
| 95 | 0: | |
| 96 | movl r4,r0 # return stashed pointer | |
| 97 | ret |