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Diffstat (limited to 'ports/sysdeps/alpha/strncpy.S')
| -rw-r--r-- | ports/sysdeps/alpha/strncpy.S | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/ports/sysdeps/alpha/strncpy.S b/ports/sysdeps/alpha/strncpy.S new file mode 100644 index 0000000000..c370e0850b --- /dev/null +++ b/ports/sysdeps/alpha/strncpy.S @@ -0,0 +1,87 @@ +/* Copyright (C) 1996, 1997, 2003 Free Software Foundation, Inc. + Contributed by Richard Henderson (rth@tamu.edu) + This file is part of the GNU C Library. + + 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. */ + +#include <sysdep.h> + + .set noat + .set noreorder + + .text + +ENTRY(strncpy) + ldgp gp, 0(pv) +#ifdef PROF + lda AT, _mcount + jsr AT, (AT), _mcount +#endif + .prologue 1 + + mov a0, v0 # set return value now + beq a2, $zerocount + jsr t9, __stxncpy # do the work of the copy + + bne a2, $multiword # do we have full words left? + + .align 3 + subq t8, 1, t2 # e0 : guess not + subq t10, 1, t3 # .. e1 : + or t2, t8, t2 # e0 : clear the bits between the last + or t3, t10, t3 # .. e1 : written byte and the last byte in + andnot t3, t2, t3 # e0 : COUNT + zap t0, t3, t0 # e1 : + stq_u t0, 0(a0) # e0 : + ret # .. e1 : + +$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 : + +$zerocount: + ret # .. e1 : + + END(strncpy) +libc_hidden_builtin_def (strncpy) |