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author | Russ Cox <rsc@golang.org> | 2014-06-26 11:54:39 -0400 |
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committer | Russ Cox <rsc@golang.org> | 2014-06-26 11:54:39 -0400 |
commit | 133cf52dde3138763a10d29f376f5fc353b6e99c (patch) | |
tree | ff01fff7fd753e3208f025eea572bc904c516ef0 /src/cmd/5a | |
parent | dfa5443fe442274dc9ffd6b076e879040b3303e1 (diff) | |
download | go-133cf52dde3138763a10d29f376f5fc353b6e99c.tar.gz |
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 ?s) 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://codereview.appspot.com/109050043
Diffstat (limited to 'src/cmd/5a')
-rw-r--r-- | src/cmd/5a/lex.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/src/cmd/5a/lex.c b/src/cmd/5a/lex.c index 571fdf7f2..84a17d155 100644 --- a/src/cmd/5a/lex.c +++ b/src/cmd/5a/lex.c @@ -199,8 +199,8 @@ struct "R6", LREG, 6, "R7", LREG, 7, "R8", LREG, 8, - "m", LREG, 9, // avoid unintentionally clobber m/g using R9/R10 - "g", LREG, 10, + "R9", LREG, 9, + "g", LREG, 10, // avoid unintentionally clobber g using R10 "R11", LREG, 11, "R12", LREG, 12, "R13", LREG, 13, |