linux/arch/arc/lib/memset-archs.S

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/*
* Copyright (C) 2014-15 Synopsys, Inc. (www.synopsys.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#undef PREALLOC_NOT_AVAIL
#ifdef PREALLOC_NOT_AVAIL
#define PREWRITE(A,B) prefetchw [(A),(B)]
#else
#define PREWRITE(A,B) prealloc [(A),(B)]
#endif
ENTRY(memset)
prefetchw [r0] ; Prefetch the write location
mov.f 0, r2
;;; if size is zero
jz.d [blink]
mov r3, r0 ; don't clobber ret val
;;; if length < 8
brls.d.nt r2, 8, .Lsmallchunk
mov.f lp_count,r2
and.f r4, r0, 0x03
rsub lp_count, r4, 4
lpnz @.Laligndestination
;; LOOP BEGIN
stb.ab r1, [r3,1]
sub r2, r2, 1
.Laligndestination:
;;; Destination is aligned
and r1, r1, 0xFF
asl r4, r1, 8
or r4, r4, r1
asl r5, r4, 16
or r5, r5, r4
mov r4, r5
sub3 lp_count, r2, 8
cmp r2, 64
bmsk.hi r2, r2, 5
mov.ls lp_count, 0
add3.hi r2, r2, 8
;;; Convert len to Dwords, unfold x8
lsr.f lp_count, lp_count, 6
lpnz @.Lset64bytes
;; LOOP START
PREWRITE(r3, 64) ;Prefetch the next write location
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
.Lset64bytes:
lsr.f lp_count, r2, 5 ;Last remaining max 124 bytes
lpnz .Lset32bytes
;; LOOP START
prefetchw [r3, 32] ;Prefetch the next write location
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
.Lset32bytes:
and.f lp_count, r2, 0x1F ;Last remaining 31 bytes
.Lsmallchunk:
lpnz .Lcopy3bytes
;; LOOP START
stb.ab r1, [r3, 1]
.Lcopy3bytes:
j [blink]
END(memset)
ENTRY(memzero)
; adjust bzero args to memset args
mov r2, r1
b.d memset ;tail call so need to tinker with blink
mov r1, 0
END(memzero)