Commit Graph

5 Commits

Author SHA1 Message Date
Russ Cox 19309779ac all: gofmt main repo
[This CL is part of a sequence implementing the proposal #51082.
The design doc is at https://go.dev/s/godocfmt-design.]

Run the updated gofmt, which reformats doc comments,
on the main repository. Vendored files are excluded.

For #51082.

Change-Id: I7332f099b60f716295fb34719c98c04eb1a85407
Reviewed-on: https://go-review.googlesource.com/c/go/+/384268
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
2022-04-11 16:34:30 +00:00
Keith Randall fb05948d9e cmd/compile,math: improve code generation for math.Abs
Implement int reg <-> fp reg moves on amd64.
If we see a load to int reg followed by an int->fp move, then we can just
load to the fp reg instead.  Same for stores.

math.Abs is now:

MOVQ	"".x+8(SP), AX
SHLQ	$1, AX
SHRQ	$1, AX
MOVQ	AX, "".~r1+16(SP)

math.Copysign is now:

MOVQ	"".x+8(SP), AX
SHLQ	$1, AX
SHRQ	$1, AX
MOVQ	"".y+16(SP), CX
SHRQ	$63, CX
SHLQ	$63, CX
ORQ	CX, AX
MOVQ	AX, "".~r2+24(SP)

math.Float64bits is now:

MOVSD	"".x+8(SP), X0
MOVSD	X0, "".~r1+16(SP)
(it would be nicer to use a non-SSE reg for this, nothing is perfect)

And due to the fix for #21440, the inlined version of these improve as well.

name      old time/op  new time/op  delta
Abs       1.38ns ± 5%  0.89ns ±10%  -35.54%  (p=0.000 n=10+10)
Copysign  1.56ns ± 7%  1.35ns ± 6%  -13.77%  (p=0.000 n=9+10)

Fixes #13095

Change-Id: Ibd7f2792412a6668608780b0688a77062e1f1499
Reviewed-on: https://go-review.googlesource.com/58732
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>
2017-08-25 19:15:01 +00:00
Brad Fitzpatrick a59a27564b math: fix typo and braino in my earlier commit
The bug number was a typo, and I forgot to switch the implementation
back to if statements after the change from Float64bits in the first
patchset back to branching.

if statements can currently be inlined, but switch cannot (#13071)

Change-Id: I81d0cf64bda69186c3d747a07047f6a694f8fa70
Reviewed-on: https://go-review.googlesource.com/16446
Reviewed-by: Robert Griesemer <gri@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-10-29 21:12:08 +00:00
Brad Fitzpatrick 6f8a66536b math: replace assembly implementations of Abs with pure Go version
The compiler can do a fine job, and can also inline it.

From Jeremy Jackins's observation and rsc's recommendation in thread:

"Pure Go math.Abs outperforms assembly version"
https://groups.google.com/forum/#!topic/golang-dev/nP5mWvwAXZo

Updates #13095

Change-Id: I3066f8eaa327bb403173b29791cc8661d7c0532c
Reviewed-on: https://go-review.googlesource.com/16444
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2015-10-29 19:44:59 +00:00
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