linux/arch/arc/lib/memset-archs.S
Vineet Gupta 86effd0dc6 ARC: dw2 unwind: enable cfi pseudo ops in string lib
This uses a new set of annoations viz. ENTRY_CFI/END_CFI to enabel cfi
ops generation.

Note that we didn't change the normal ENTRY/EXIT as we don't actually
want unwind info in the trap/exception/interrutp handlers which use
these, as unwinder then gets confused (it keeps recursing vs. stopping).
Semantically these are leaf routines and unwinding should stop when it
hits those routines.

Before
------

    28.52%     1.19%          9929  hackbench  libuClibc-1.0.17.so   [.] __write_nocancel
            |
            ---__write_nocancel
               |--8.95%--EV_Trap
               |           --8.25%--sys_write
               |                     |--3.93%--sock_write_iter
     ...
               |--2.62%--memset   <==== [LEAF entry as no unwind info]
                         ^^^^^^

After
-----

    29.46%     1.24%         13622  hackbench  libuClibc-1.0.17.so   [.] __write_nocancel
            |
            ---__write_nocancel
               |--9.31%--EV_Trap
               |           --8.62%--sys_write
               |                     |--4.17%--sock_write_iter
     ...
               |--6.19%--sys_write
               |           --6.19%--sock_write_iter
               |                     unix_stream_sendmsg
               |                     |--1.62%--sock_alloc_send_pskb
               |                     |--0.89%--sock_def_readable
               |                     |--0.88%--_raw_spin_unlock_irqrestore
               |                     |--0.69%--memset
               |                     |         ^^^^^^     <==== [now in proper callframe]
               |                     |
               |                      --0.52%--skb_copy_datagram_from_iter

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2016-09-30 14:48:22 -07:00

123 lines
2.3 KiB
ArmAsm

/*
* 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
ENTRY_CFI(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
#ifdef PREALLOC_NOT_AVAIL
prefetchw [r3, 64] ;Prefetch the next write location
#else
prealloc [r3, 64]
#endif
#ifdef CONFIG_ARC_HAS_LL64
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]
#else
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
#endif
.Lset64bytes:
lsr.f lp_count, r2, 5 ;Last remaining max 124 bytes
lpnz .Lset32bytes
;; LOOP START
prefetchw [r3, 32] ;Prefetch the next write location
#ifdef CONFIG_ARC_HAS_LL64
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
std.ab r4, [r3, 8]
#else
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
st.ab r4, [r3, 4]
#endif
.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_CFI(memset)
ENTRY_CFI(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_CFI(memzero)