| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Returns 0 if exception before NUL or reaching the supplied limit (N), |
| 3 | * a value greater than N if the string is longer than the limit, else |
| 4 | * strlen. |
| 5 | * |
| 6 | * Inputs: |
| 7 | * in0: address of buffer |
| 8 | * in1: string length limit N |
| 9 | * Outputs: |
| 10 | * r8: 0 in case of fault, strlen(buffer)+1 otherwise |
| 11 | * |
| 12 | * Copyright (C) 1999, 2001 David Mosberger-Tang <davidm@hpl.hp.com> |
| 13 | */ |
| 14 | |
| 15 | #include <asm/asmmacro.h> |
| 16 | |
| 17 | GLOBAL_ENTRY(__strnlen_user) |
| 18 | .prologue |
| 19 | alloc r2=ar.pfs,2,0,0,0 |
| 20 | .save ar.lc, r16 |
| 21 | mov r16=ar.lc // preserve ar.lc |
| 22 | |
| 23 | .body |
| 24 | |
| 25 | add r3=-1,in1 |
| 26 | ;; |
| 27 | mov ar.lc=r3 |
| 28 | mov r9=0 |
| 29 | ;; |
| 30 | // XXX braindead strlen loop---this needs to be optimized |
| 31 | .Loop1: |
| 32 | EXCLR(.Lexit, ld1 r8=[in0],1) |
| 33 | add r9=1,r9 |
| 34 | ;; |
| 35 | cmp.eq p6,p0=r8,r0 |
| 36 | (p6) br.cond.dpnt .Lexit |
| 37 | br.cloop.dptk.few .Loop1 |
| 38 | |
| 39 | add r9=1,in1 // NUL not found---return N+1 |
| 40 | ;; |
| 41 | .Lexit: |
| 42 | mov r8=r9 |
| 43 | mov ar.lc=r16 // restore ar.lc |
| 44 | br.ret.sptk.many rp |
| 45 | END(__strnlen_user) |