/*****************************************************************************
* cpu-a.S: arm cpu detection
*****************************************************************************
* Copyright (C) 2013-2017 MulticoreWare, Inc
*
* Authors: David Conrad <lessen42@gmail.com>
* Dnyaneshwar Gorade <dnyaneshwar@multicorewareinc.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02111, USA.
*
* This program is also available under a commercial proprietary license.
* For more information, contact us at license @ x265.com.
*****************************************************************************/
#include "asm.S"
.align 2
// done in gas because .fpu neon overrides the refusal to assemble
// instructions the selected -march/-mcpu doesn't support
function x265_cpu_neon_test
vadd.i16 q0, q0, q0
bx lr
endfunc
// return: 0 on success
// 1 if counters were already enabled
// 9 if lo-res counters were already enabled
function x265_cpu_enable_armv7_counter, export=0
mrc p15, 0, r2, c9, c12, 0 // read PMNC
ands r0, r2, #1
andne r0, r2, #9
orr r2, r2, #1 // enable counters
bic r2, r2, #8 // full resolution
mcreq p15, 0, r2, c9, c12, 0 // write PMNC
mov r2, #1 << 31 // enable cycle counter
mcr p15, 0, r2, c9, c12, 1 // write CNTENS
bx lr
endfunc
function x265_cpu_disable_armv7_counter, export=0
mrc p15, 0, r0, c9, c12, 0 // read PMNC
bic r0, r0, #1 // disable counters
mcr p15, 0, r0, c9, c12, 0 // write PMNC
bx lr
endfunc
.macro READ_TIME r
mrc p15, 0, \r, c9, c13, 0
.endm
// return: 0 if transfers neon -> arm transfers take more than 10 cycles
// nonzero otherwise
function x265_cpu_fast_neon_mrc_test
// check for user access to performance counters
mrc p15, 0, r0, c9, c14, 0
cmp r0, #0
bxeq lr
push {r4-r6,lr}
bl x265_cpu_enable_armv7_counter
ands r1, r0, #8
mov r3, #0
mov ip, #4
mov r6, #4
moveq r5, #1
movne r5, #64
average_loop:
mov r4, r5
READ_TIME r1
1: subs r4, r4, #1
.rept 8
vmov.u32 lr, d0[0]
add lr, lr, lr
.endr
bgt 1b
READ_TIME r2
subs r6, r6, #1
sub r2, r2, r1
cmpgt r2, #30 << 3 // assume context switch if it took over 30 cycles
addle r3, r3, r2
subsle ip, ip, #1
bgt average_loop
// disable counters if we enabled them
ands r0, r0, #1
bleq x265_cpu_disable_armv7_counter
lsr r0, r3, #5
cmp r0, #10
movgt r0, #0
pop {r4-r6,pc}
endfunc