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| Commit | Line | Data |
|---|---|---|
| dadab5a2 | 1 | /* strncat.s 4.2 84/11/01 */ |
| 4bd005a5 SL |
2 | |
| 3 | /* | |
| 4 | * Concatenate string s2 on the end of s1 | |
| 5 | * and return the base of s1. The parameter | |
| 6 | * n is the maximum length of string s2 to | |
| 7 | * concatenate. | |
| 8 | * | |
| 9 | * char * | |
| 10 | * strncat(s1, s2, n) | |
| 11 | * char *s1, *s2; | |
| 12 | * int n; | |
| 13 | */ | |
| dadab5a2 | 14 | #include "DEFS.h" |
| 4bd005a5 | 15 | |
| dadab5a2 | 16 | ENTRY(strncat, R6) |
| 4bd005a5 SL |
17 | movl 12(ap),r6 # r6 = n |
| 18 | bleq done # n <= 0 | |
| 19 | movl 4(ap),r3 # r3 = s1 | |
| 20 | movl r3,r1 | |
| 21 | 0: | |
| 22 | locc $0,$65535,(r1) | |
| 23 | beql 0b | |
| 24 | movl r1,r3 # r3 = index(s1, '\0'); | |
| 25 | movl 8(ap),r1 # r1 = s2 | |
| 26 | 1: | |
| 27 | movzwl $65535,r2 # r2 = bytes in first chunk | |
| 28 | cmpl r6,r2 # r2 = min(bytes in chunk, n); | |
| 29 | jgeq 2f | |
| 30 | movl r6,r2 | |
| 31 | 2: | |
| 32 | subl2 r2,r6 # update n | |
| 33 | locc $0,r2,(r1) # '\0' found? | |
| 34 | jneq 3f | |
| 35 | subl2 r2,r1 # back up pointer updated by locc | |
| 36 | movc3 r2,(r1),(r3) # copy in next piece | |
| 37 | tstl r6 # run out of space? | |
| 38 | jneq 1b | |
| 39 | clrb (r3) # force '\0' termination | |
| 40 | jbr done | |
| 41 | 3: | |
| 42 | subl2 r0,r2 # r2 = number of bytes to move | |
| 43 | subl2 r2,r1 # back up pointer updated by locc | |
| 44 | incl r2 # copy '\0' as well | |
| 45 | movc3 r2,(r1),(r3) # copy in last piece | |
| 46 | done: | |
| 47 | movl 4(ap),r0 # return s1 | |
| 48 | ret |