| /* Copyright (C) 1996-2016 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Richard Henderson (rth@tamu.edu) |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library. If not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| /* Copy no more than COUNT bytes of the null-terminated string from |
| SRC to DST. If SRC does not cover all of COUNT, the balance is |
| zeroed. Return the address of the terminating null in DEST, if |
| any, else DEST + COUNT. */ |
| |
| #include <sysdep.h> |
| |
| .set noat |
| .set noreorder |
| |
| .text |
| |
| ENTRY(__stpncpy) |
| ldgp gp, 0(pv) |
| #ifdef PROF |
| lda AT, _mcount |
| jsr AT, (AT), _mcount |
| #endif |
| .prologue 1 |
| |
| beq a2, $zerocount |
| jsr t9, __stxncpy # do the work of the copy |
| |
| and t8, 0xf0, t3 # binary search for byte offset of the |
| and t8, 0xcc, t2 # last byte written. |
| and t8, 0xaa, t1 |
| andnot a0, 7, v0 |
| cmovne t3, 4, t3 |
| cmovne t2, 2, t2 |
| cmovne t1, 1, t1 |
| addq v0, t3, v0 |
| addq t1, t2, t1 |
| addq v0, t1, v0 |
| |
| bne a2, $multiword # do we have full words left? |
| |
| .align 3 |
| zapnot t0, t8, t4 # e0 : was last byte a null? |
| subq t8, 1, t2 # .. e1 : |
| addq v0, 1, t5 # e0 : |
| subq t10, 1, t3 # .. e1 : |
| or t2, t8, t2 # e0 : clear the bits between the last |
| or t3, t10, t3 # .. e1 : written byte and the last byte in |
| andnot t3, t2, t3 # e0 : COUNT |
| cmovne t4, t5, v0 # .. e1 : if last written wasnt null, inc v0 |
| zap t0, t3, t0 # e0 : |
| stq_u t0, 0(a0) # e1 : |
| ret # .. e1 : |
| |
| .align 3 |
| $multiword: |
| subq t8, 1, t7 # e0 : clear the final bits in the prev |
| or t7, t8, t7 # e1 : word |
| zapnot t0, t7, t0 # e0 : |
| subq a2, 1, a2 # .. e1 : |
| stq_u t0, 0(a0) # e0 : |
| addq a0, 8, a0 # .. e1 : |
| |
| beq a2, 1f # e1 : |
| blbc a2, 0f # e1 : |
| |
| stq_u zero, 0(a0) # e0 : zero one word |
| subq a2, 1, a2 # .. e1 : |
| addq a0, 8, a0 # e0 : |
| beq a2, 1f # .. e1 : |
| |
| 0: stq_u zero, 0(a0) # e0 : zero two words |
| subq a2, 2, a2 # .. e1 : |
| stq_u zero, 8(a0) # e0 : |
| addq a0, 16, a0 # .. e1 : |
| bne a2, 0b # e1 : |
| unop |
| |
| 1: ldq_u t0, 0(a0) # e0 : clear the leading bits in the final |
| subq t10, 1, t7 # .. e1 : word |
| or t7, t10, t7 # e0 : |
| zap t0, t7, t0 # e1 (stall) |
| stq_u t0, 0(a0) # e0 : |
| ret # .. e1 : |
| |
| $zerocount: |
| mov a0, v0 |
| ret |
| |
| END(__stpncpy) |
| |
| libc_hidden_def (__stpncpy) |
| weak_alias (__stpncpy, stpncpy) |