diff options
author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2022-02-10 11:28:45 -0300 |
---|---|---|
committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2022-02-23 14:06:49 -0300 |
commit | f883dbaf1fba5b870331ce980fe2176242bea6f2 (patch) | |
tree | 65539515bc1912373044730c0ce25fcf200538d9 /sysdeps/alpha | |
parent | bf92893a14ebc161b08b28acc24fa06ae6be19cb (diff) | |
download | glibc-f883dbaf1fba5b870331ce980fe2176242bea6f2.tar.gz glibc-f883dbaf1fba5b870331ce980fe2176242bea6f2.tar.xz glibc-f883dbaf1fba5b870331ce980fe2176242bea6f2.zip |
alpha: Remove bzero optimization
The symbols is not present in current POSIX specification and compiler already generates memmove call.
Diffstat (limited to 'sysdeps/alpha')
-rw-r--r-- | sysdeps/alpha/bzero.S | 109 |
1 files changed, 0 insertions, 109 deletions
diff --git a/sysdeps/alpha/bzero.S b/sysdeps/alpha/bzero.S deleted file mode 100644 index 4821778622..0000000000 --- a/sysdeps/alpha/bzero.S +++ /dev/null @@ -1,109 +0,0 @@ -/* Copyright (C) 1996-2022 Free Software Foundation, Inc. - 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 - <https://www.gnu.org/licenses/>. */ - -/* Fill a block of memory with zeros. Optimized for the Alpha architecture: - - - memory accessed as aligned quadwords only - - destination memory not read unless needed for good cache behaviour - - basic blocks arranged to optimize branch prediction for full-quadword - aligned memory blocks. - - partial head and tail quadwords constructed with byte-mask instructions - - This is generally scheduled for the EV5 (got to look out for my own - interests :-), but with EV4 needs in mind. There *should* be no more - stalls for the EV4 than there are for the EV5. -*/ - - -#include <sysdep.h> - - .set noat - .set noreorder - - .text - .type __bzero, @function - .globl __bzero - .usepv __bzero, USEPV_PROF - - cfi_startproc - - /* On entry to this basic block: - t3 == loop counter - t4 == bytes in partial final word - a0 == possibly misaligned destination pointer */ - - .align 3 -bzero_loop: - beq t3, $tail # - blbc t3, 0f # skip single store if count even - - stq_u zero, 0(a0) # e0 : store one word - subq t3, 1, t3 # .. e1 : - addq a0, 8, a0 # e0 : - beq t3, $tail # .. e1 : - -0: stq_u zero, 0(a0) # e0 : store two words - subq t3, 2, t3 # .. e1 : - stq_u zero, 8(a0) # e0 : - addq a0, 16, a0 # .. e1 : - bne t3, 0b # e1 : - -$tail: bne t4, 1f # is there a tail to do? - ret # no - -1: ldq_u t0, 0(a0) # yes, load original data - mskqh t0, t4, t0 # - stq_u t0, 0(a0) # - ret # - -__bzero: -#ifdef PROF - ldgp gp, 0(pv) - lda AT, _mcount - jsr AT, (AT), _mcount -#endif - - mov a0, v0 # e0 : move return value in place - beq a1, $done # .. e1 : early exit for zero-length store - and a0, 7, t1 # e0 : - addq a1, t1, a1 # e1 : add dest misalignment to count - srl a1, 3, t3 # e0 : loop = count >> 3 - and a1, 7, t4 # .. e1 : find number of bytes in tail - unop # : - beq t1, bzero_loop # e1 : aligned head, jump right in - - ldq_u t0, 0(a0) # e0 : load original data to mask into - cmpult a1, 8, t2 # .. e1 : is this a sub-word set? - bne t2, $oneq # e1 : - - mskql t0, a0, t0 # e0 : we span words. finish this partial - subq t3, 1, t3 # e0 : - addq a0, 8, a0 # .. e1 : - stq_u t0, -8(a0) # e0 : - br bzero_loop # .. e1 : - - .align 3 -$oneq: - mskql t0, a0, t2 # e0 : - mskqh t0, a1, t3 # e0 : - or t2, t3, t0 # e1 : - stq_u t0, 0(a0) # e0 : - -$done: ret - - cfi_endproc -weak_alias (__bzero, bzero) |