mirror of https://github.com/golang/go.git
6 Commits
| Author | SHA1 | Message | Date |
|---|---|---|---|
cui fliter
|
d57303e65f |
math: add available godoc link
Change-Id: I4a6c2ef6fd21355952ab7d8eaad883646a95d364 Reviewed-on: https://go-review.googlesource.com/c/go/+/535087 Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Than McIntosh <thanm@google.com> |
|
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> |
|
Austin Clements
|
1d20a362d0 |
math: avoid assembly stubs
Currently almost all math functions have the following pattern:
func Sin(x float64) float64
func sin(x float64) float64 {
// ... pure Go implementation ...
}
Architectures that implement a function in assembly provide the
assembly implementation directly as the exported function (e.g., Sin),
and architectures that don't implement it in assembly use a small stub
to jump back to the Go code, like:
TEXT ·Sin(SB), NOSPLIT, $0
JMP ·sin(SB)
However, most functions are not implemented in assembly on most
architectures, so this jump through assembly is a waste. It defeats
compiler optimizations like inlining. And, with regabi, it actually
adds a small but non-trivial overhead because the jump from assembly
back to Go must go through an ABI0->ABIInternal bridge function.
Hence, this CL reorganizes this structure across the entire package.
It now leans on inlining to achieve peak performance, but allows the
compiler to see all the way through the pure Go implementation.
Now, functions follow this pattern:
func Sin(x float64) float64 {
if haveArchSin {
return archSin(x)
}
return sin(x)
}
func sin(x float64) float64 {
// ... pure Go implementation ...
}
Architectures that have assembly implementations use build-tagged
files to set haveArchX to true an provide an archX implementation.
That implementation can also still call back into the Go
implementation (some of them do this).
Prior to this change, enabling ABI wrappers results in a geomean
slowdown of the math benchmarks of 8.77% (full results:
https://perf.golang.org/search?q=upload:20210415.6) and of the Tile38
benchmarks by ~4%. After this change, enabling ABI wrappers is
completely performance-neutral on Tile38 and all but one math
benchmark (full results:
https://perf.golang.org/search?q=upload:20210415.7). ABI wrappers slow
down SqrtIndirectLatency-12 by 2.09%, which makes sense because that
call must still go through an ABI wrapper.
With ABI wrappers disabled (which won't be an option on amd64 much
longer), on linux/amd64, this change is largely performance-neutral
and slightly improves the performance of a few benchmarks:
(Because there are so many benchmarks, I've applied the Šidák
correction to the alpha threshold. It makes relatively little
difference in which benchmarks are statistically significant.)
name old time/op new time/op delta
Acos-12 22.3ns ± 0% 18.8ns ± 1% -15.44% (p=0.000 n=18+16)
Acosh-12 28.2ns ± 0% 28.2ns ± 0% ~ (p=0.404 n=18+20)
Asin-12 18.1ns ± 0% 18.2ns ± 0% +0.20% (p=0.000 n=18+16)
Asinh-12 32.8ns ± 0% 32.9ns ± 1% ~ (p=0.891 n=18+20)
Atan-12 9.92ns ± 0% 9.90ns ± 1% -0.24% (p=0.000 n=17+16)
Atanh-12 27.7ns ± 0% 27.5ns ± 0% -0.72% (p=0.000 n=16+20)
Atan2-12 18.5ns ± 0% 18.4ns ± 0% -0.59% (p=0.000 n=19+19)
Cbrt-12 22.1ns ± 0% 22.1ns ± 0% ~ (p=0.804 n=16+17)
Ceil-12 0.84ns ± 0% 0.84ns ± 0% ~ (p=0.663 n=18+16)
Copysign-12 0.84ns ± 0% 0.84ns ± 0% ~ (p=0.762 n=16+19)
Cos-12 12.7ns ± 0% 12.7ns ± 1% ~ (p=0.145 n=19+18)
Cosh-12 22.2ns ± 0% 22.5ns ± 0% +1.60% (p=0.000 n=17+19)
Erf-12 11.1ns ± 1% 11.1ns ± 1% ~ (p=0.010 n=19+19)
Erfc-12 12.6ns ± 1% 12.7ns ± 0% ~ (p=0.066 n=19+15)
Erfinv-12 16.1ns ± 0% 16.1ns ± 0% ~ (p=0.462 n=17+20)
Erfcinv-12 16.0ns ± 1% 16.0ns ± 1% ~ (p=0.015 n=17+16)
Exp-12 16.3ns ± 0% 16.5ns ± 1% +1.25% (p=0.000 n=19+16)
ExpGo-12 36.2ns ± 1% 36.1ns ± 1% ~ (p=0.242 n=20+18)
Expm1-12 18.6ns ± 0% 18.7ns ± 0% +0.25% (p=0.000 n=16+19)
Exp2-12 34.7ns ± 0% 34.6ns ± 1% ~ (p=0.010 n=19+18)
Exp2Go-12 34.8ns ± 1% 34.8ns ± 1% ~ (p=0.372 n=19+19)
Abs-12 0.56ns ± 0% 0.56ns ± 0% ~ (p=0.766 n=18+16)
Dim-12 0.84ns ± 1% 0.84ns ± 1% ~ (p=0.167 n=17+19)
Floor-12 0.84ns ± 0% 0.84ns ± 0% ~ (p=0.993 n=18+16)
Max-12 3.35ns ± 0% 3.35ns ± 0% ~ (p=0.894 n=17+19)
Min-12 3.35ns ± 0% 3.36ns ± 1% ~ (p=0.214 n=18+18)
Mod-12 35.2ns ± 0% 34.7ns ± 0% -1.45% (p=0.000 n=18+17)
Frexp-12 5.31ns ± 0% 4.75ns ± 0% -10.51% (p=0.000 n=19+18)
Gamma-12 14.8ns ± 0% 16.2ns ± 1% +9.21% (p=0.000 n=20+19)
Hypot-12 6.16ns ± 0% 6.17ns ± 0% +0.26% (p=0.000 n=19+20)
HypotGo-12 7.79ns ± 1% 7.78ns ± 0% ~ (p=0.497 n=18+17)
Ilogb-12 4.47ns ± 0% 4.47ns ± 0% ~ (p=0.167 n=19+19)
J0-12 76.0ns ± 0% 76.3ns ± 0% +0.35% (p=0.000 n=19+18)
J1-12 76.8ns ± 1% 75.9ns ± 0% -1.14% (p=0.000 n=18+18)
Jn-12 167ns ± 1% 168ns ± 1% ~ (p=0.038 n=18+18)
Ldexp-12 6.98ns ± 0% 6.43ns ± 0% -7.97% (p=0.000 n=17+18)
Lgamma-12 15.9ns ± 0% 16.0ns ± 1% ~ (p=0.011 n=20+17)
Log-12 13.3ns ± 0% 13.4ns ± 1% +0.37% (p=0.000 n=15+18)
Logb-12 4.75ns ± 0% 4.75ns ± 0% ~ (p=0.831 n=16+18)
Log1p-12 19.5ns ± 0% 19.5ns ± 1% ~ (p=0.851 n=18+17)
Log10-12 15.9ns ± 0% 14.0ns ± 0% -11.92% (p=0.000 n=17+16)
Log2-12 7.88ns ± 1% 8.01ns ± 0% +1.72% (p=0.000 n=20+20)
Modf-12 4.75ns ± 0% 4.34ns ± 0% -8.66% (p=0.000 n=19+17)
Nextafter32-12 5.31ns ± 0% 5.31ns ± 0% ~ (p=0.389 n=17+18)
Nextafter64-12 5.03ns ± 1% 5.03ns ± 0% ~ (p=0.774 n=17+18)
PowInt-12 29.9ns ± 0% 28.5ns ± 0% -4.69% (p=0.000 n=18+19)
PowFrac-12 91.0ns ± 0% 91.1ns ± 0% ~ (p=0.029 n=19+19)
Pow10Pos-12 1.12ns ± 0% 1.12ns ± 0% ~ (p=0.363 n=20+20)
Pow10Neg-12 3.90ns ± 0% 3.90ns ± 0% ~ (p=0.921 n=17+18)
Round-12 2.31ns ± 0% 2.31ns ± 1% ~ (p=0.390 n=18+18)
RoundToEven-12 0.84ns ± 0% 0.84ns ± 0% ~ (p=0.280 n=18+19)
Remainder-12 31.6ns ± 0% 29.6ns ± 0% -6.16% (p=0.000 n=18+17)
Signbit-12 0.56ns ± 0% 0.56ns ± 0% ~ (p=0.385 n=19+18)
Sin-12 12.5ns ± 0% 12.5ns ± 0% ~ (p=0.080 n=18+18)
Sincos-12 16.4ns ± 2% 16.4ns ± 2% ~ (p=0.253 n=20+19)
Sinh-12 26.1ns ± 0% 26.1ns ± 0% +0.18% (p=0.000 n=17+19)
SqrtIndirect-12 3.91ns ± 0% 3.90ns ± 0% ~ (p=0.133 n=19+19)
SqrtLatency-12 2.79ns ± 0% 2.79ns ± 0% ~ (p=0.226 n=16+19)
SqrtIndirectLatency-12 6.68ns ± 0% 6.37ns ± 2% -4.66% (p=0.000 n=17+20)
SqrtGoLatency-12 49.4ns ± 0% 49.4ns ± 0% ~ (p=0.289 n=18+16)
SqrtPrime-12 3.18µs ± 0% 3.18µs ± 0% ~ (p=0.084 n=17+18)
Tan-12 13.8ns ± 0% 13.9ns ± 2% ~ (p=0.292 n=19+20)
Tanh-12 25.4ns ± 0% 25.4ns ± 0% ~ (p=0.101 n=17+17)
Trunc-12 0.84ns ± 0% 0.84ns ± 0% ~ (p=0.765 n=18+16)
Y0-12 75.8ns ± 0% 75.9ns ± 1% ~ (p=0.805 n=16+18)
Y1-12 76.3ns ± 0% 75.3ns ± 1% -1.34% (p=0.000 n=19+17)
Yn-12 164ns ± 0% 164ns ± 2% ~ (p=0.356 n=18+20)
Float64bits-12 0.56ns ± 0% 0.56ns ± 0% ~ (p=0.383 n=18+18)
Float64frombits-12 0.56ns ± 0% 0.56ns ± 0% ~ (p=0.066 n=18+19)
Float32bits-12 0.56ns ± 0% 0.56ns ± 0% ~ (p=0.889 n=16+19)
Float32frombits-12 0.56ns ± 0% 0.56ns ± 0% ~ (p=0.007 n=18+19)
FMA-12 23.9ns ± 0% 24.0ns ± 0% +0.31% (p=0.000 n=16+17)
[Geo mean] 9.86ns 9.77ns -0.87%
(https://perf.golang.org/search?q=upload:20210415.5)
For #40724.
Change-Id: I44fbba2a17be930ec9daeb0a8222f55cd50555a0
Reviewed-on: https://go-review.googlesource.com/c/go/+/310331
Trust: Austin Clements <austin@google.com>
Reviewed-by: Cherry Zhang <cherryyz@google.com>
|
|
crvv
|
d46953c9f6 |
math: fix inaccurate result of Exp(1)
The existing implementation is translated from C, which uses a polynomial coefficient very close to 1/6. If the function uses 1/6 as this coeffient, the result of Exp(1) will be more accurate. And this change doesn't introduce more error to Exp function. Fixes #20319 Change-Id: I94c236a18cf95570ebb69f7fb99884b0d7cf5f6e Reviewed-on: https://go-review.googlesource.com/49294 Reviewed-by: Robert Griesemer <gri@golang.org> |
|
Brad Fitzpatrick
|
5fea2ccc77 |
all: single space after period.
The tree's pretty inconsistent about single space vs double space after a period in documentation. Make it consistently a single space, per earlier decisions. This means contributors won't be confused by misleading precedence. This CL doesn't use go/doc to parse. It only addresses // comments. It was generated with: $ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])') $ go test go/doc -update Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7 Reviewed-on: https://go-review.googlesource.com/20022 Reviewed-by: Rob Pike <r@golang.org> Reviewed-by: Dave Day <djd@golang.org> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> |
|
|
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. |