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linux-next/arch/arc/lib/memcpy-700.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

67 lines
1.2 KiB
ArmAsm

/*
* Copyright (C) 2004, 2007-2010, 2011-2012 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>
ENTRY_CFI(memcpy)
or r3,r0,r1
asl_s r3,r3,30
mov_s r5,r0
brls.d r2,r3,.Lcopy_bytewise
sub.f r3,r2,1
ld_s r12,[r1,0]
asr.f lp_count,r3,3
bbit0.d r3,2,.Lnox4
bmsk_s r2,r2,1
st.ab r12,[r5,4]
ld.a r12,[r1,4]
.Lnox4:
lppnz .Lendloop
ld_s r3,[r1,4]
st.ab r12,[r5,4]
ld.a r12,[r1,8]
st.ab r3,[r5,4]
.Lendloop:
breq r2,0,.Last_store
ld r3,[r5,0]
#ifdef __LITTLE_ENDIAN__
add3 r2,-1,r2
; uses long immediate
xor_s r12,r12,r3
bmsk r12,r12,r2
xor_s r12,r12,r3
#else /* BIG ENDIAN */
sub3 r2,31,r2
; uses long immediate
xor_s r3,r3,r12
bmsk r3,r3,r2
xor_s r12,r12,r3
#endif /* ENDIAN */
.Last_store:
j_s.d [blink]
st r12,[r5,0]
.balign 4
.Lcopy_bytewise:
jcs [blink]
ldb_s r12,[r1,0]
lsr.f lp_count,r3
bhs_s .Lnox1
stb.ab r12,[r5,1]
ldb.a r12,[r1,1]
.Lnox1:
lppnz .Lendbloop
ldb_s r3,[r1,1]
stb.ab r12,[r5,1]
ldb.a r12,[r1,2]
stb.ab r3,[r5,1]
.Lendbloop:
j_s.d [blink]
stb r12,[r5,0]
END_CFI(memcpy)