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6d1a70dd0a
freebsd-skq/sys
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Ryan Libby 6d1a70dd0a amd64 atomic.h: minor codegen optimization in flag access 
Previously the pattern to extract status flags from inline assembly
blocks was to use setcc in the block to write the flag to a register.
This was suboptimal in a few ways:
 - It would lead to code like: sete %cl; test %cl; jne, i.e. a flag
   would just be loaded into a register and then reloaded to a flag.
 - The setcc would force the block to use an additional register.
 - If the client code didn't care for the flag value then the setcc
   would be entirely pointless but could not be eliminated by the
   optimizer.

A more modern inline asm construct (since gcc 6 and clang 9) allows for
"flag output operands", where a C variable can be written directly from
a flag.  The optimizer can then use this to produce direct code where
the flag does not take a trip through a register.

In practice this makes each affected operation sequence shorter by five
bytes of instructions.  It's unlikely this has a measurable performance
impact.

Reviewed by:	kib, markj, mjg
Sponsored by:	Dell EMC Isilon
Differential Revision:	https://reviews.freebsd.org/D23869
2020-02-28 18:32:36 +00:00
..
amd64 amd64 atomic.h: minor codegen optimization in flag access 2020-02-28 18:32:36 +00:00
arm arm: zynq: An SPI driver for Zynq platforms 2020-02-28 10:57:23 +00:00
arm64 Fix the cache type identification 2020-02-26 15:56:07 +00:00
bsm vfs: add realpathat syscall 2020-02-20 16:58:19 +00:00
cam This is a FALLTHROUGH for sure. no need for xxx comment. 2020-02-28 01:18:11 +00:00
cddl Clear systrace_args_func when systrace probes are disabled. 2020-02-28 17:04:36 +00:00
compat Make linuxulator warn about unsupported getsockopt/setsockopt flags. 2020-02-27 19:40:20 +00:00
conf Better check for floating point type. 2020-02-27 15:34:30 +00:00
contrib With the planned removal of GIANT (sysctl uses GIANT), make future-proof 2020-02-26 20:18:38 +00:00
crypto Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
ddb Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
dev Add Denverton UART PCI ID 2020-02-28 15:59:35 +00:00
dts arm: zynq: An SPI driver for Zynq platforms 2020-02-28 10:57:23 +00:00
fs Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
gdb Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
geom Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
gnu dts: Update our copy for arm, arm64 and riscv dts to Linux 5.5 2020-02-28 15:42:51 +00:00
i386 Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
isa sc(4) md bits: stop setting sc->kbd entirely 2019-12-30 02:07:55 +00:00
kern Fix standalone builds of systrace.ko after r357912. 2020-02-28 17:05:04 +00:00
kgssapi Stop using des_cblock * for arguments to DES functions. 2019-08-26 17:25:07 +00:00
libkern Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
mips Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
modules linuxkpi: Move shmem related functions in it's own file 2020-02-21 09:28:45 +00:00
net Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
net80211 Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (7 of many) 2020-02-21 16:32:17 +00:00
netgraph Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
netinet Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
netinet6 mld6: initialize oifp to avoid bogus results/panics in edge cases 2020-02-28 11:16:41 +00:00
netipsec Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
netpfil Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
netsmb Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
nfs Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
nfsclient
nfsserver
nlm Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
ofed Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
opencrypto Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
powerpc Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
riscv riscv: Add a GENERIC-NODEBUG (copied from amd64) 2020-02-27 20:26:37 +00:00
rpc Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
security Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
sys Fix r358436 to not declare kernel symbols when _KERNEL is not defined. 2020-02-28 17:38:31 +00:00
teken Adjust teken to allow build as part of loader 2019-09-05 18:07:40 +00:00
tests Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
tools vfs: stop null checking routines in vop wrappers 2020-01-26 00:41:38 +00:00
ufs Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
vm Add a blocking counter KPI. 2020-02-28 16:05:18 +00:00
x86 Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (17 of many) 2020-02-26 14:26:36 +00:00
xdr typo: s/impelmentation/implementation/. 2020-02-07 15:14:29 +00:00
xen Mark more nodes as CTLFLAG_MPSAFE or CTLFLAG_NEEDGIANT (16 of many) 2020-02-25 19:04:39 +00:00
Makefile Remove sparc64 kernel support 2020-02-03 17:35:11 +00:00