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Diffstat (limited to 'sysdeps/alpha/memchr.S')
| -rw-r--r-- | sysdeps/alpha/memchr.S | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/sysdeps/alpha/memchr.S b/sysdeps/alpha/memchr.S deleted file mode 100644 index 5d713d53ba..0000000000 --- a/sysdeps/alpha/memchr.S +++ /dev/null @@ -1,176 +0,0 @@ -/* Copyright (C) 1996, 2000, 2003 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by David Mosberger (davidm@cs.arizona.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, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA - 02111-1307 USA. */ - -/* Finds characters in a memory area. Optimized for the Alpha: - - - memory accessed as aligned quadwords only - - uses cmpbge to compare 8 bytes in parallel - - does binary search to find 0 byte in last - quadword (HAKMEM needed 12 instructions to - do this instead of the 9 instructions that - binary search needs). - -For correctness consider that: - - - only minimum number of quadwords may be accessed - - the third argument is an unsigned long -*/ - -#include <sysdep.h> - - .set noreorder - .set noat - -ENTRY(__memchr) -#ifdef PROF - ldgp gp, 0(pv) - lda AT, _mcount - jsr AT, (AT), _mcount - .prologue 1 -#else - .prologue 0 -#endif - - # Hack -- if someone passes in (size_t)-1, hoping to just - # search til the end of the address space, we will overflow - # below when we find the address of the last byte. Given - # that we will never have a 56-bit address space, cropping - # the length is the easiest way to avoid trouble. - zap a2, 0x80, t4 #-e0 : - - beq a2, $not_found # .. e1 : - ldq_u t0, 0(a0) # e1 : load first quadword - insbl a1, 1, t1 # .. e0 : t1 = 000000000000ch00 - and a1, 0xff, a1 #-e0 : a1 = 00000000000000ch - cmpult a2, 9, t3 # .. e1 : - or t1, a1, a1 # e0 : a1 = 000000000000chch - lda t2, -1(zero) # .. e1 : - sll a1, 16, t1 #-e0 : t1 = 00000000chch0000 - addq a0, t4, t4 # .. e1 : - or t1, a1, a1 # e1 : a1 = 00000000chchchch - unop # : - sll a1, 32, t1 #-e0 : t1 = chchchch00000000 - or t1, a1, a1 # e1 : a1 = chchchchchchchch - extql t0, a0, t6 # e0 : - beq t3, $first_quad # .. e1 : - - ldq_u t5, -1(t4) #-e1 : eight or less bytes to search - extqh t5, a0, t5 # .. e0 : - mov a0, v0 # e0 : - or t6, t5, t0 # .. e1 : t0 = quadword starting at a0 - - # Deal with the case where at most 8 bytes remain to be searched - # in t0. E.g.: - # a2 = 6 - # t0 = ????c6c5c4c3c2c1 -$last_quad: - negq a2, t5 #-e0 : - xor a1, t0, t0 # .. e1 : - srl t2, t5, t5 # e0 : t5 = mask of a2 bits set - cmpbge zero, t0, t1 # .. e1 : - and t1, t5, t1 #-e0 : - beq t1, $not_found # .. e1 : - -$found_it: - # Now, determine which byte matched: - negq t1, t2 # e0 : - and t1, t2, t1 # e1 : - - and t1, 0x0f, t0 #-e0 : - addq v0, 4, t2 # .. e1 : - cmoveq t0, t2, v0 # e0 : - - addq v0, 2, t2 # .. e1 : - and t1, 0x33, t0 #-e0 : - cmoveq t0, t2, v0 # .. e1 : - - and t1, 0x55, t0 # e0 : - addq v0, 1, t2 # .. e1 : - cmoveq t0, t2, v0 #-e0 : - -$done: ret # .. e1 : - - # Deal with the case where a2 > 8 bytes remain to be - # searched. a0 may not be aligned. - .align 4 -$first_quad: - andnot a0, 0x7, v0 #-e1 : - insqh t2, a0, t1 # .. e0 : t1 = 0000ffffffffffff (a0<0:2> ff) - xor t0, a1, t0 # e0 : - or t0, t1, t0 # e1 : t0 = ====ffffffffffff - cmpbge zero, t0, t1 #-e0 : - bne t1, $found_it # .. e1 : - - # At least one byte left to process. - - ldq t0, 8(v0) # e0 : - subq t4, 1, a2 # .. e1 : - addq v0, 8, v0 #-e0 : - - # Make a2 point to last quad to be accessed (the - # last quad may or may not be partial). - - andnot a2, 0x7, a2 # .. e1 : - cmpult v0, a2, t1 # e0 : - beq t1, $final # .. e1 : - - # At least two quads remain to be accessed. - - subq a2, v0, t3 #-e0 : t3 <- nr quads to be processed - and t3, 8, t3 # e1 : odd number of quads? - bne t3, $odd_quad_count # e1 : - - # At least three quads remain to be accessed - - mov t0, t3 # e0 : move prefetched value to correct reg - - .align 4 -$unrolled_loop: - ldq t0, 8(v0) #-e0 : prefetch t0 - xor a1, t3, t1 # .. e1 : - cmpbge zero, t1, t1 # e0 : - bne t1, $found_it # .. e1 : - - addq v0, 8, v0 #-e0 : -$odd_quad_count: - xor a1, t0, t1 # .. e1 : - ldq t3, 8(v0) # e0 : prefetch t3 - cmpbge zero, t1, t1 # .. e1 : - addq v0, 8, t5 #-e0 : - bne t1, $found_it # .. e1 : - - cmpult t5, a2, t5 # e0 : - addq v0, 8, v0 # .. e1 : - bne t5, $unrolled_loop #-e1 : - - mov t3, t0 # e0 : move prefetched value into t0 -$final: subq t4, v0, a2 # .. e1 : a2 <- number of bytes left to do - bne a2, $last_quad # e1 : - -$not_found: - mov zero, v0 #-e0 : - ret # .. e1 : - - END(__memchr) - -weak_alias (__memchr, memchr) -#if !__BOUNDED_POINTERS__ -weak_alias (__memchr, __ubp_memchr) -#endif -libc_hidden_builtin_def (memchr) |