projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| a35f6d0c KB |
1 | /* |
| 2 | * Copyright (c) 1988 Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * Redistribution and use in source and binary forms are permitted | |
| 6 | * provided that this notice is preserved and that due credit is given | |
| 7 | * to the University of California at Berkeley. The name of the University | |
| 8 | * may not be used to endorse or promote products derived from this | |
| 9 | * software without specific written prior permission. This software | |
| 10 | * is provided ``as is'' without express or implied warranty. | |
| 11 | */ | |
| 12 | ||
| 13 | #if defined(SYSLIBC_SCCS) && !defined(lint) | |
| 14 | _sccsid:.asciz "@(#)strchr.s 5.1 (Berkeley) %G%" | |
| 15 | #endif /* SYSLIBC_SCCS and not lint */ | |
| 16 | ||
| 17 | #ifdef notdef | |
| 18 | _sccsid:.asciz "@(#)index.s 5.4 (Berkeley) 5/25/88" | |
| 19 | #endif | |
| 20 | ||
| 21 | /* | |
| 22 | * Find the first occurence of c in the string cp. | |
| 23 | * Return pointer to match or null pointer. | |
| 24 | * | |
| 25 | * char * | |
| 26 | * index(cp, c) | |
| 27 | * char *cp, c; | |
| 28 | */ | |
| 29 | #include "DEFS.h" | |
| 30 | ||
| 31 | ENTRY(strchr, 0) | |
| 32 | movq 4(ap),r1 # r1 = cp; r2 = c | |
| 33 | tstl r2 # check for special case c == '\0' | |
| 34 | bneq 2f | |
| 35 | 1: | |
| 36 | locc $0,$65535,(r1) # just find end of string | |
| 37 | beql 1b # still looking | |
| 38 | movl r1,r0 # found it | |
| 39 | ret | |
| 40 | 2: | |
| 41 | moval tbl,r3 # r3 = address of table | |
| 42 | bbss $0,(r3),5f # insure not reentering | |
| 43 | movab (r3)[r2],r5 # table entry for c | |
| 44 | incb (r5) | |
| 45 | movzwl $65535,r4 # fast access | |
| 46 | 3: | |
| 47 | scanc r4,(r1),(r3),$1 # look for c or '\0' | |
| 48 | beql 3b # still looking | |
| 49 | movl r1,r0 # return pointer to char | |
| 50 | tstb (r0) # if have found '\0' | |
| 51 | bneq 4f | |
| 52 | clrl r0 # else return 0 | |
| 53 | 4: | |
| 54 | clrb (r5) # clean up table | |
| 55 | clrb (r3) | |
| 56 | ret | |
| 57 | ||
| 58 | .data | |
| 59 | tbl: .space 256 | |
| 60 | .text | |
| 61 | ||
| 62 | /* | |
| 63 | * Reentrant, but slower version of index | |
| 64 | */ | |
| 65 | 5: | |
| 66 | movl r1,r3 | |
| 67 | 6: | |
| 68 | locc $0,$65535,(r3) # look for '\0' | |
| 69 | bneq 7f | |
| 70 | locc r2,$65535,(r3) # look for c | |
| 71 | bneq 8f | |
| 72 | movl r1,r3 # reset pointer and ... | |
| 73 | jbr 6b # ... try again | |
| 74 | 7: | |
| 75 | subl3 r3,r1,r4 # length of short block | |
| 76 | incl r4 # +1 for '\0' | |
| 77 | locc r2,r4,(r3) # look for c | |
| 78 | bneq 8f | |
| 79 | ret | |
| 80 | 8: | |
| 81 | movl r1,r0 # return pointer to char | |
| 82 | ret |