go/include
Russ Cox 89f185fe8a all: remove 'extern register M *m' from runtime
The runtime has historically held two dedicated values g (current goroutine)
and m (current thread) in 'extern register' slots (TLS on x86, real registers
backed by TLS on ARM).

This CL removes the extern register m; code now uses g->m.

On ARM, this frees up the register that formerly held m (R9).
This is important for NaCl, because NaCl ARM code cannot use R9 at all.

The Go 1 macrobenchmarks (those with per-op times >= 10 µs) are unaffected:

BenchmarkBinaryTree17              5491374955     5471024381     -0.37%
BenchmarkFannkuch11                4357101311     4275174828     -1.88%
BenchmarkGobDecode                 11029957       11364184       +3.03%
BenchmarkGobEncode                 6852205        6784822        -0.98%
BenchmarkGzip                      650795967      650152275      -0.10%
BenchmarkGunzip                    140962363      141041670      +0.06%
BenchmarkHTTPClientServer          71581          73081          +2.10%
BenchmarkJSONEncode                31928079       31913356       -0.05%
BenchmarkJSONDecode                117470065      113689916      -3.22%
BenchmarkMandelbrot200             6008923        5998712        -0.17%
BenchmarkGoParse                   6310917        6327487        +0.26%
BenchmarkRegexpMatchMedium_1K      114568         114763         +0.17%
BenchmarkRegexpMatchHard_1K        168977         169244         +0.16%
BenchmarkRevcomp                   935294971      914060918      -2.27%
BenchmarkTemplate                  145917123      148186096      +1.55%

Minux previous reported larger variations, but these were caused by
run-to-run noise, not repeatable slowdowns.

Actual code changes by Minux.
I only did the docs and the benchmarking.

LGTM=dvyukov, iant, minux
R=minux, josharian, iant, dave, bradfitz, dvyukov
CC=golang-codereviews
https://golang.org/cl/109050043
2014-06-26 11:54:39 -04:00
..
plan9 include/plan9: make mklibc.rc compatible with 9atom 2014-04-19 09:55:09 +02:00
ar.h gopack: change archive file name length back to 16 2011-11-01 00:29:16 -04:00
bio.h libbio, libmach: warnings from the Plan 9 tool chain 2014-04-07 08:40:13 -07:00
fmt.h convert C runtime to 32-bit runes; 2009-08-31 16:38:50 -07:00
libc.h cmd/dist, cmd/ld: GO_EXTLINK_ENABLED=0 defaults to -linkmode=internal 2013-03-29 16:33:35 -07:00
link.h all: remove 'extern register M *m' from runtime 2014-06-26 11:54:39 -04:00
README include: add a README file 2013-05-22 18:51:15 +08:00
u.h liblink: create new library based on linker code 2013-12-08 22:49:37 -05:00
utf.h add missing include file 2008-06-12 13:31:17 -07:00

The header files under this directory are strictly internal to the gc
toolchain, so please don't copy them to the system include file
directory (/usr/include, /usr/local/include, etc.)

Also note that they must be kept as is in $GOROOT/include, or cmd/dist
will malfunction.