mirror of
https://github.com/torvalds/linux.git
synced 2024-11-15 00:21:59 +00:00
86effd0dc6
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>
134 lines
2.7 KiB
ArmAsm
134 lines
2.7 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.
|
|
*/
|
|
|
|
/* ARC700 has a relatively long pipeline and branch prediction, so we want
|
|
to avoid branches that are hard to predict. On the other hand, the
|
|
presence of the norm instruction makes it easier to operate on whole
|
|
words branch-free. */
|
|
|
|
#include <linux/linkage.h>
|
|
|
|
ENTRY_CFI(strchr)
|
|
extb_s r1,r1
|
|
asl r5,r1,8
|
|
bmsk r2,r0,1
|
|
or r5,r5,r1
|
|
mov_s r3,0x01010101
|
|
breq.d r2,r0,.Laligned
|
|
asl r4,r5,16
|
|
sub_s r0,r0,r2
|
|
asl r7,r2,3
|
|
ld_s r2,[r0]
|
|
#ifdef __LITTLE_ENDIAN__
|
|
asl r7,r3,r7
|
|
#else
|
|
lsr r7,r3,r7
|
|
#endif
|
|
or r5,r5,r4
|
|
ror r4,r3
|
|
sub r12,r2,r7
|
|
bic_s r12,r12,r2
|
|
and r12,r12,r4
|
|
brne.d r12,0,.Lfound0_ua
|
|
xor r6,r2,r5
|
|
ld.a r2,[r0,4]
|
|
sub r12,r6,r7
|
|
bic r12,r12,r6
|
|
#ifdef __LITTLE_ENDIAN__
|
|
and r7,r12,r4
|
|
breq r7,0,.Loop ; For speed, we want this branch to be unaligned.
|
|
b .Lfound_char ; Likewise this one.
|
|
#else
|
|
and r12,r12,r4
|
|
breq r12,0,.Loop ; For speed, we want this branch to be unaligned.
|
|
lsr_s r12,r12,7
|
|
bic r2,r7,r6
|
|
b.d .Lfound_char_b
|
|
and_s r2,r2,r12
|
|
#endif
|
|
; /* We require this code address to be unaligned for speed... */
|
|
.Laligned:
|
|
ld_s r2,[r0]
|
|
or r5,r5,r4
|
|
ror r4,r3
|
|
; /* ... so that this code address is aligned, for itself and ... */
|
|
.Loop:
|
|
sub r12,r2,r3
|
|
bic_s r12,r12,r2
|
|
and r12,r12,r4
|
|
brne.d r12,0,.Lfound0
|
|
xor r6,r2,r5
|
|
ld.a r2,[r0,4]
|
|
sub r12,r6,r3
|
|
bic r12,r12,r6
|
|
and r7,r12,r4
|
|
breq r7,0,.Loop /* ... so that this branch is unaligned. */
|
|
; Found searched-for character. r0 has already advanced to next word.
|
|
#ifdef __LITTLE_ENDIAN__
|
|
/* We only need the information about the first matching byte
|
|
(i.e. the least significant matching byte) to be exact,
|
|
hence there is no problem with carry effects. */
|
|
.Lfound_char:
|
|
sub r3,r7,1
|
|
bic r3,r3,r7
|
|
norm r2,r3
|
|
sub_s r0,r0,1
|
|
asr_s r2,r2,3
|
|
j.d [blink]
|
|
sub_s r0,r0,r2
|
|
|
|
.balign 4
|
|
.Lfound0_ua:
|
|
mov r3,r7
|
|
.Lfound0:
|
|
sub r3,r6,r3
|
|
bic r3,r3,r6
|
|
and r2,r3,r4
|
|
or_s r12,r12,r2
|
|
sub_s r3,r12,1
|
|
bic_s r3,r3,r12
|
|
norm r3,r3
|
|
add_s r0,r0,3
|
|
asr_s r12,r3,3
|
|
asl.f 0,r2,r3
|
|
sub_s r0,r0,r12
|
|
j_s.d [blink]
|
|
mov.pl r0,0
|
|
#else /* BIG ENDIAN */
|
|
.Lfound_char:
|
|
lsr r7,r7,7
|
|
|
|
bic r2,r7,r6
|
|
.Lfound_char_b:
|
|
norm r2,r2
|
|
sub_s r0,r0,4
|
|
asr_s r2,r2,3
|
|
j.d [blink]
|
|
add_s r0,r0,r2
|
|
|
|
.Lfound0_ua:
|
|
mov_s r3,r7
|
|
.Lfound0:
|
|
asl_s r2,r2,7
|
|
or r7,r6,r4
|
|
bic_s r12,r12,r2
|
|
sub r2,r7,r3
|
|
or r2,r2,r6
|
|
bic r12,r2,r12
|
|
bic.f r3,r4,r12
|
|
norm r3,r3
|
|
|
|
add.pl r3,r3,1
|
|
asr_s r12,r3,3
|
|
asl.f 0,r2,r3
|
|
add_s r0,r0,r12
|
|
j_s.d [blink]
|
|
mov.mi r0,0
|
|
#endif /* ENDIAN */
|
|
END_CFI(strchr)
|