This is a crude compiler pass to eliminate stores to auto variables
that are only ever written to.
Eliminates an unnecessary store to x from the following code:
func f() int {
var x := 1
return *(&x)
}
Fixes#19765.
Change-Id: If2c63a8ae67b8c590b6e0cc98a9610939a3eeffa
Reviewed-on: https://go-review.googlesource.com/38746
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
This is an extension of
https://go-review.googlesource.com/c/31662/
to mark all the temporaries, not just the ssa-generated ones.
Before-and-after ls -l `go tool -n compile` shows a 3%
reduction in size (or rather, a prior 3% inflation for
failing to filter temps out properly.)
Replaced name-dependent "is it a temp?" tests with calls to
*Node.IsAutoTmp(), which depends on AutoTemp. Also replace
calls to istemp(n) with n.IsAutoTmp(), to reduce duplication
and clean up function name space. Generated temporaries
now come with a "." prefix to avoid (apparently harmless)
clashes with legal Go variable names.
Fixes#17644.
Fixes#17240.
Change-Id: If1417f29c79a7275d7303ddf859b51472890fd43
Reviewed-on: https://go-review.googlesource.com/32255
Run-TryBot: David Chase <drchase@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Some tests disabled, some bifurcated into _ssa and not,
with appropriate logging added to compiler.
"tests/live.go" in particular needs attention.
SSA-specific testing removed, since it's all SSA now.
Added "-run_skips" option to tests/run.go to simplify
checking whether a test still fails (or how it fails)
on a skipped platform.
The compiler now compiles with SSA by default.
If you don't want SSA, specify GOSSAHASH=n (or N) as
an environment variable. Function names ending in "_ssa"
are always SSA-compiled.
GOSSAFUNC=fname retains its "SSA for fname, log to ssa.html"
GOSSAPKG=pkg only has an effect when GOSSAHASH=n
GOSSAHASH=10101 etc retains its name-hash-matching behavior
for purposes of debugging.
See #13068
Change-Id: I8217bfeb34173533eaeb391b5f6935483c7d6b43
Reviewed-on: https://go-review.googlesource.com/16299
Reviewed-by: Keith Randall <khr@golang.org>
Run-TryBot: David Chase <drchase@google.com>
Now each C printf, Go print, or Go println is guaranteed
not to be interleaved with other calls of those functions.
This should help when debugging concurrent failures.
LGTM=rlh
R=rlh
CC=golang-codereviews
https://golang.org/cl/169120043
A write *p = x that needs a write barrier (not all do)
now turns into runtime.writebarrierptr(p, x)
or one of the other variants.
The write barrier implementations are trivial.
The goal here is to emit the calls in the correct places
and to incur the cost of those function calls in the Go 1.4 cycle.
Performance on the Go 1 benchmark suite below.
Remember, the goal is to slow things down (and be correct).
We will look into optimizations in separate CLs, as part of
the process of comparing Go 1.3 against tip in order to make
sure Go 1.4 runs at least as fast as Go 1.3.
benchmark old ns/op new ns/op delta
BenchmarkBinaryTree17 3118336716 3452876110 +10.73%
BenchmarkFannkuch11 3184497677 3211552284 +0.85%
BenchmarkFmtFprintfEmpty 89.9 107 +19.02%
BenchmarkFmtFprintfString 236 287 +21.61%
BenchmarkFmtFprintfInt 246 278 +13.01%
BenchmarkFmtFprintfIntInt 395 458 +15.95%
BenchmarkFmtFprintfPrefixedInt 343 378 +10.20%
BenchmarkFmtFprintfFloat 477 525 +10.06%
BenchmarkFmtManyArgs 1446 1707 +18.05%
BenchmarkGobDecode 14398047 14685958 +2.00%
BenchmarkGobEncode 12557718 12947104 +3.10%
BenchmarkGzip 453462345 472413285 +4.18%
BenchmarkGunzip 114226016 115127398 +0.79%
BenchmarkHTTPClientServer 114689 112122 -2.24%
BenchmarkJSONEncode 24914536 26135942 +4.90%
BenchmarkJSONDecode 86832877 103620289 +19.33%
BenchmarkMandelbrot200 4833452 4898780 +1.35%
BenchmarkGoParse 4317976 4835474 +11.98%
BenchmarkRegexpMatchEasy0_32 150 166 +10.67%
BenchmarkRegexpMatchEasy0_1K 393 402 +2.29%
BenchmarkRegexpMatchEasy1_32 125 142 +13.60%
BenchmarkRegexpMatchEasy1_1K 1010 1236 +22.38%
BenchmarkRegexpMatchMedium_32 232 301 +29.74%
BenchmarkRegexpMatchMedium_1K 76963 102721 +33.47%
BenchmarkRegexpMatchHard_32 3833 5463 +42.53%
BenchmarkRegexpMatchHard_1K 119668 161614 +35.05%
BenchmarkRevcomp 763449047 706768534 -7.42%
BenchmarkTemplate 124954724 134834549 +7.91%
BenchmarkTimeParse 517 511 -1.16%
BenchmarkTimeFormat 501 514 +2.59%
benchmark old MB/s new MB/s speedup
BenchmarkGobDecode 53.31 52.26 0.98x
BenchmarkGobEncode 61.12 59.28 0.97x
BenchmarkGzip 42.79 41.08 0.96x
BenchmarkGunzip 169.88 168.55 0.99x
BenchmarkJSONEncode 77.89 74.25 0.95x
BenchmarkJSONDecode 22.35 18.73 0.84x
BenchmarkGoParse 13.41 11.98 0.89x
BenchmarkRegexpMatchEasy0_32 213.30 191.72 0.90x
BenchmarkRegexpMatchEasy0_1K 2603.92 2542.74 0.98x
BenchmarkRegexpMatchEasy1_32 254.00 224.93 0.89x
BenchmarkRegexpMatchEasy1_1K 1013.53 827.98 0.82x
BenchmarkRegexpMatchMedium_32 4.30 3.31 0.77x
BenchmarkRegexpMatchMedium_1K 13.30 9.97 0.75x
BenchmarkRegexpMatchHard_32 8.35 5.86 0.70x
BenchmarkRegexpMatchHard_1K 8.56 6.34 0.74x
BenchmarkRevcomp 332.92 359.62 1.08x
BenchmarkTemplate 15.53 14.39 0.93x
LGTM=rlh
R=rlh
CC=dvyukov, golang-codereviews, iant, khr, r
https://golang.org/cl/136380043
The 'address taken' bit in a function variable was not
propagating into the inlined copies, causing incorrect
liveness information.
LGTM=dsymonds, bradfitz
R=golang-codereviews, bradfitz
CC=dsymonds, golang-codereviews, iant, khr, r
https://golang.org/cl/96670046
