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Commit Graph

10 Commits

Author SHA1 Message Date
Sebastien Binet
918fdae348 reflect: implement ArrayOf
This change exposes reflect.ArrayOf to create new reflect.Type array
types at runtime, when given a reflect.Type element.

- reflect: implement ArrayOf
- reflect: tests for ArrayOf
- runtime: document that typeAlg is used by reflect and must be kept in
  synchronized

Fixes #5996.

Change-Id: I5d07213364ca915c25612deea390507c19461758
Reviewed-on: https://go-review.googlesource.com/4111
Reviewed-by: Keith Randall <khr@golang.org>
2015-04-21 15:21:09 +00:00
Michael Hudson-Doyle
ab4df700b8 runtime: merge slice and sliceStruct
By removing type slice, renaming type sliceStruct to type slice and
whacking until it compiles.

Has a pleasing net reduction of conversions.

Fixes #10188

Change-Id: I77202b8df637185b632fd7875a1fdd8d52c7a83c
Reviewed-on: https://go-review.googlesource.com/8770
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-04-15 16:59:49 +00:00
Keith Randall
d5e4c4061b runtime: remove size argument from hash and equal algorithms
The equal algorithm used to take the size
   equal(p, q *T, size uintptr) bool
With this change, it does not
   equal(p, q *T) bool
Similarly for the hash algorithm.

The size is rarely used, as most equal functions know the size
of the thing they are comparing.  For instance f32equal already
knows its inputs are 4 bytes in size.

For cases where the size is not known, we allocate a closure
(one for each size needed) that points to an assembly stub that
reads the size out of the closure and calls generic code that
has a size argument.

Reduces the size of the go binary by 0.07%.  Performance impact
is not measurable.

Change-Id: I6e00adf3dde7ad2974adbcff0ee91e86d2194fec
Reviewed-on: https://go-review.googlesource.com/2392
Reviewed-by: Russ Cox <rsc@golang.org>
2015-01-07 21:57:01 +00:00
Keith Randall
ce5cb037d1 runtime: use some startup randomness in the fallback hashes
Fold in some startup randomness to make the hash vary across
different runs.  This helps prevent attackers from choosing
keys that all map to the same bucket.

Also, reorganize the hash a bit.  Move the *m1 multiply to after
the xor of the current hash and the message.  For hash quality
it doesn't really matter, but for DDOS resistance it helps a lot
(any processing done to the message before it is merged with the
random seed is useless, as it is easily inverted by an attacker).

Update #9365

Change-Id: Ib19968168e1bbc541d1d28be2701bb83e53f1e24
Reviewed-on: https://go-review.googlesource.com/2344
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2015-01-07 16:02:05 +00:00
Keith Randall
b1f29b2d44 runtime: get rid of goalg, no longer needed
The goalg function was a holdover from when we had algorithm
tables in both C and Go.  It is no longer needed.

Change-Id: Ia0c1af35bef3497a899f22084a1a7b42daae72a0
Reviewed-on: https://go-review.googlesource.com/2099
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2014-12-28 18:42:39 +00:00
Keith Randall
cda0ea1c0e runtime: a better fallback hash
For arm and powerpc, as well as x86 without aes instructions.
Contains a mixture of ideas from cityhash and xxhash.

Compared to our old fallback on ARM, it's ~no slower on
small objects and up to ~50% faster on large objects.  More
importantly, it is a much better hash function and thus has
less chance of bad behavior.

Fixes #8737

benchmark                         old ns/op     new ns/op     delta
BenchmarkHash5                    173           181           +4.62%
BenchmarkHash16                   252           212           -15.87%
BenchmarkHash64                   575           419           -27.13%
BenchmarkHash1024                 7173          3995          -44.31%
BenchmarkHash65536                516940        313173        -39.42%
BenchmarkHashStringSpeed          300           279           -7.00%
BenchmarkHashBytesSpeed           478           424           -11.30%
BenchmarkHashInt32Speed           217           207           -4.61%
BenchmarkHashInt64Speed           262           231           -11.83%
BenchmarkHashStringArraySpeed     609           631           +3.61%

Change-Id: I0a9335028f32b10ad484966e3019987973afd3eb
Reviewed-on: https://go-review.googlesource.com/1360
Reviewed-by: Russ Cox <rsc@golang.org>
2014-12-22 22:41:01 +00:00
Keith Randall
7a4a64e8f3 runtime: faster aeshash implementation
The aesenc instruction has high latency.  For hashing large objects,
hash several streams in parallel.

benchmark                         old ns/op     new ns/op     delta
BenchmarkHash5                    7.02          7.45          +6.13%
BenchmarkHash16                   6.53          6.94          +6.28%
BenchmarkHash32                   8.38          8.26          -1.43%
BenchmarkHash64                   12.6          12.0          -4.76%
BenchmarkHash1024                 247           62.9          -74.53%
BenchmarkHash65536                17335         2966          -82.89%
BenchmarkHashInt32Speed           14.7          14.9          +1.36%
BenchmarkHashInt64Speed           14.6          14.9          +2.05%
BenchmarkHashBytesSpeed           35.4          28.6          -19.21%
BenchmarkHashStringSpeed          22.0          20.4          -7.27%
BenchmarkHashStringArraySpeed     65.8          56.3          -14.44%

Change-Id: Ia8ba03063acc64a9066b8ab2d79f2c9aaac1770f
Reviewed-on: https://go-review.googlesource.com/1330
Reviewed-by: Russ Cox <rsc@golang.org>
2014-12-11 05:23:00 +00:00
Keith Randall
6820be25da runtime: clean up & go-ify the hash function seeder
Change-Id: I0e95f8a5962c547da20e19a356ae1cf8375c9107
Reviewed-on: https://go-review.googlesource.com/1270
Reviewed-by: Russ Cox <rsc@golang.org>
2014-12-10 21:15:35 +00:00
Russ Cox
e785e3acf8 [dev.cc] runtime: convert operating system support code from C to Go
The conversion was done with an automated tool and then
modified only as necessary to make it compile and run.

[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]

LGTM=r
R=r
CC=austin, dvyukov, golang-codereviews, iant, khr
https://golang.org/cl/174830044
2014-11-11 17:08:54 -05:00
Russ Cox
c007ce824d build: move package sources from src/pkg to src
Preparation was in CL 134570043.
This CL contains only the effect of 'hg mv src/pkg/* src'.
For more about the move, see golang.org/s/go14nopkg.
2014-09-08 00:08:51 -04:00