delta/go-git.git/src/math/big, branch dev.debug

math/big: fix Add, Sub when receiver aliases 2nd operand

2017-05-31T10:28:05+00:00

Fixes #20490

Change-Id: I9cfa604f9ff94df779cb9b4cbbd706258fc473ac
Reviewed-on: https://go-review.googlesource.com/44150
Run-TryBot: Alberto Donizetti 
TryBot-Result: Gobot Gobot 
Reviewed-by: Keith Randall

math/big: improve performance for addVV/subVV for ppc64x

2017-04-25T13:15:39+00:00

This change adds a better asm implementation of addVV for ppc64x, with speedups
up to nearly 3x in the best cases.

benchmark                   old ns/op     new ns/op     delta
BenchmarkAddVV/1-8          7.33          5.81          -20.74%
BenchmarkAddVV/2-8          8.72          6.49          -25.57%
BenchmarkAddVV/3-8          10.5          7.08          -32.57%
BenchmarkAddVV/4-8          12.7          7.57          -40.39%
BenchmarkAddVV/5-8          14.3          8.06          -43.64%
BenchmarkAddVV/10-8         27.6          11.1          -59.78%
BenchmarkAddVV/100-8        218           82.4          -62.20%
BenchmarkAddVV/1000-8       2064          718           -65.21%
BenchmarkAddVV/10000-8      20536         7153          -65.17%
BenchmarkAddVV/100000-8     211004        72403         -65.69%

benchmark                   old MB/s     new MB/s     speedup
BenchmarkAddVV/1-8          8729.74      11006.26     1.26x
BenchmarkAddVV/2-8          14683.65     19707.55     1.34x
BenchmarkAddVV/3-8          18226.96     27103.63     1.49x
BenchmarkAddVV/4-8          20204.50     33805.81     1.67x
BenchmarkAddVV/5-8          22348.64     39694.06     1.78x
BenchmarkAddVV/10-8         23212.74     57631.08     2.48x
BenchmarkAddVV/100-8        29300.07     77629.53     2.65x
BenchmarkAddVV/1000-8       31000.56     89094.54     2.87x
BenchmarkAddVV/10000-8      31163.61     89469.16     2.87x
BenchmarkAddVV/100000-8     30331.16     88393.73     2.91x

It also adds the use of CTR for the loop counter in subVV, instead of
manually updating the loop counter. This is slightly faster.

Change-Id: Ic4b05cad384fd057972d46a5618ed5c3039d7460
Reviewed-on: https://go-review.googlesource.com/41010
Run-TryBot: Lynn Boger 
TryBot-Result: Gobot Gobot 
Reviewed-by: Lynn Boger

all: fix minor misspellings

2017-04-03T23:19:07+00:00

Change-Id: I1f1cfb161640eb8756fb1a283892d06b30b7a8fa
Reviewed-on: https://go-review.googlesource.com/39356
Reviewed-by: Brad Fitzpatrick 
Run-TryBot: Brad Fitzpatrick 
TryBot-Result: Gobot Gobot

math/big: Unify divWW implementation for ppc64 and ppc64le.

2017-03-31T14:05:12+00:00

Starting in go1.9, the minimum processor requirement for ppc64 is POWER8. So it
may now use the same divWW implementation as ppc64le.

Updates #19074

Change-Id: If1a85f175cda89eee06a1024ccd468da6124c844
Reviewed-on: https://go-review.googlesource.com/39010
Run-TryBot: Brad Fitzpatrick 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick 
Reviewed-by: Lynn Boger

math/big: replace local versions of bitLen, nlz with math/bits versions

2017-03-23T19:43:09+00:00

Verified that BenchmarkBitLen time went down from 2.25 ns/op to 0.65 ns/op
an a 2.3 GHz Intel Core i7, before removing that benchmark (now covered by
math/bits benchmarks).

Change-Id: I3890bb7d1889e95b9a94bd68f0bdf06f1885adeb
Reviewed-on: https://go-review.googlesource.com/38464
Run-TryBot: Robert Griesemer 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick

math/big: fix TestFloatSetFloat64String

2017-03-23T17:17:16+00:00

A -0 constant is the same as 0. Use explicit negative zero
for float64 -0.0. Also, fix two test cases that were wrong.

Fixes #19673.

Change-Id: Ic09775f29d9bc2ee7814172e59c4a693441ea730
Reviewed-on: https://go-review.googlesource.com/38463
Run-TryBot: Robert Griesemer 
Reviewed-by: Brad Fitzpatrick 
Reviewed-by: Ian Lance Taylor

math/big: make nat.setUint64 vet-friendly

2017-03-11T00:39:23+00:00

nat.setUint64 is nicely generic.
By assuming 32- or 64-bit words, however,
we can write simpler code,
and eliminate some shifts
in dead code that vet complains about.

Generated code for 64 bit systems is unaltered.
Generated code for 32 bit systems is much better.
For 386, the routine length drops from 325
bytes of code to 271 bytes of code, with fewer loops.

Change-Id: I1bc14c06272dee37a7fcb48d33dd1e621eba945d
Reviewed-on: https://go-review.googlesource.com/38070
Run-TryBot: Josh Bleecher Snyder 
TryBot-Result: Gobot Gobot 
Reviewed-by: Robert Griesemer

all: remove the the duplicate words

2017-03-06T04:39:12+00:00

Change-Id: I6343c162e27e2e492547c96f1fc504909b1c03c0
Reviewed-on: https://go-review.googlesource.com/37793
Reviewed-by: Daniel Martí 
Reviewed-by: Ian Lance Taylor 
Run-TryBot: Ian Lance Taylor 
TryBot-Result: Gobot Gobot

math/big: use math/bits where appropriate

2017-02-24T19:19:02+00:00

This change adds math/bits as a new dependency of math/big.

- use bits.LeadingZeroes instead of local implementation
  (they are identical, so there's no performance loss here)

- leave other functionality local (ntz, bitLen) since there's
  faster implementations in math/big at the moment

Change-Id: I1218aa8a1df0cc9783583b090a4bb5a8a145c4a2
Reviewed-on: https://go-review.googlesource.com/37141
Reviewed-by: Brad Fitzpatrick

math/big: define Word as uint instead of uintptr

2017-02-21T19:31:40+00:00

For compatibility with math/bits uint operations.

When math/big was written originally, the Go compiler used 32bit
int/uint values even on a 64bit machine. uintptr was the type that
represented the machine register size. Now, the int/uint types are
sized to the native machine register size, so they are the natural
machine Word type.

On most machines, the size of int/uint correspond to the size of
uintptr. On platforms where uint and uintptr have different sizes,
this change may lead to performance differences (e.g., amd64p32).

Change-Id: Ief249c160b707b6441848f20041e32e9e9d8d8ca
Reviewed-on: https://go-review.googlesource.com/37372
Run-TryBot: Robert Griesemer 
TryBot-Result: Gobot Gobot 
Reviewed-by: Brad Fitzpatrick