[PATCH v2 05/11] alpha: Remove bzero optimization (original) (raw)
Adhemerval Zanella adhemerval.zanella@linaro.org
Wed Feb 23 14:09:15 GMT 2022
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The symbols is not present in current POSIX specification and compiler already generates memmove call.
sysdeps/alpha/bzero.S | 109 ------------------------------------------ 1 file changed, 109 deletions(-) delete mode 100644 sysdeps/alpha/bzero.S
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 countert4 == bytes in partial final worda0 == 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)
2.32.0
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