projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 586c39b1 DF |
1 | /* |
| 2 | * Copyright (c) 1983 Regents of the University of California. | |
| 493b70ca KB |
3 | * All rights reserved. |
| 4 | * | |
| 019bea33 | 5 | * %sccs.include.redist.c% |
| 586c39b1 DF |
6 | */ |
| 7 | ||
| f4f66d2c | 8 | #if defined(LIBC_SCCS) && !defined(lint) |
| 019bea33 | 9 | .asciz "@(#)rindex.s 5.6 (Berkeley) %G%" |
| f4f66d2c | 10 | #endif /* LIBC_SCCS and not lint */ |
| a01b1b6c SL |
11 | |
| 12 | /* | |
| 13 | * Find the last occurence of c in the string cp. | |
| 14 | * Return pointer to match or null pointer. | |
| 15 | * | |
| 16 | * char * | |
| 17 | * rindex(cp, c) | |
| 18 | * char *cp, c; | |
| 19 | */ | |
| dadab5a2 | 20 | #include "DEFS.h" |
| a01b1b6c | 21 | |
| dadab5a2 | 22 | ENTRY(rindex, 0) |
| a01b1b6c SL |
23 | movq 4(ap),r1 # r1 = cp; r2 = c |
| 24 | tstl r2 # check for special case c == '\0' | |
| 25 | bneq 2f | |
| 26 | 1: | |
| 27 | locc $0,$65535,(r1) # just find end of string | |
| 28 | beql 1b # still looking | |
| 29 | movl r1,r0 # found it | |
| 30 | ret | |
| 31 | 2: | |
| 8f899db2 KM |
32 | moval tbl,r3 # r3 = address of table |
| 33 | bbss $0,(r3),5f # insure not reentering | |
| 34 | movab (r3)[r2],r5 # table entry for c | |
| a01b1b6c SL |
35 | incb (r5) |
| 36 | clrl r4 # last found | |
| 37 | 3: | |
| 8f899db2 | 38 | scanc $65535,(r1),(r3),$1 # look for c or '\0' |
| a01b1b6c SL |
39 | beql 3b # keep looking |
| 40 | tstb (r1) # if have found '\0' | |
| 41 | beql 4f # we are done | |
| 42 | movl r1,r4 # save most recently found | |
| 43 | incl r1 # skip over character | |
| 44 | jbr 3b # keep looking | |
| 45 | 4: | |
| 46 | movl r4,r0 # return last found (if any) | |
| 47 | clrb (r5) # clean up table | |
| 8f899db2 | 48 | clrb (r3) |
| a01b1b6c SL |
49 | ret |
| 50 | ||
| 51 | .data | |
| 8f899db2 | 52 | tbl: .space 256 |
| a01b1b6c | 53 | .text |
| 8f899db2 KM |
54 | |
| 55 | /* | |
| 56 | * Reentrant, but slower version of rindex | |
| 57 | */ | |
| 58 | 5: | |
| 59 | movl r1,r3 | |
| 60 | clrl r4 # r4 = pointer to last match | |
| 61 | 6: | |
| 62 | locc $0,$65535,(r3) # look for '\0' | |
| 63 | bneq 8f | |
| 64 | decw r0 # r0 = 65535 | |
| 65 | 1: | |
| 66 | locc r2,r0,(r3) # look for c | |
| 67 | bneq 7f | |
| 68 | movl r1,r3 # reset pointer and ... | |
| 69 | jbr 6b # ... try again | |
| 70 | 7: | |
| 71 | movl r1,r4 # stash pointer ... | |
| 72 | addl3 $1,r1,r3 # ... skip over match and ... | |
| 73 | decl r0 # ... decrement count | |
| 74 | jbr 6b # ... try again | |
| 75 | 8: | |
| 76 | subl3 r3,r1,r0 # length of short block | |
| 77 | incl r0 # +1 for '\0' | |
| 78 | 9: | |
| 79 | locc r2,r0,(r3) # look for c | |
| 80 | beql 0f | |
| 81 | movl r1,r4 # stash pointer ... | |
| 82 | addl3 $1,r1,r3 # ... skip over match ... | |
| 83 | decl r0 # ... adjust count and ... | |
| 84 | jbr 9b # ... try again | |
| 85 | 0: | |
| 86 | movl r4,r0 # return stashed pointer | |
| 87 | ret |