apd: Improve string conversion efficiency #125
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
nvanbenschoten
approved these changes
Oct 17, 2022
bench_test.go
Outdated
| if err != nil { | ||
| b.Fatal(err) | ||
| } | ||
| res[i] = d |
There was a problem hiding this comment.
nit, but can we simplify this to:
for i := range res {
_, err := res[i].SetFloat64(..)
if err != nil {
b.Fatal(err)
}
}| @@ -57,7 +57,8 @@ func (d *Decimal) Append(buf []byte, fmt byte) []byte { | |||
| return append(buf, "unknown"...) | |||
| } | |||
|
|
|||
| digits := d.Coeff.String() | |||
| var scratch [16]byte | |||
There was a problem hiding this comment.
Does scratch escape to the heap? If it does, could we Append directly to buf? Or temporarily use the spare capacity at the end of buf? fmtE and fmtF look like they might make that tricky.
There was a problem hiding this comment.
Doesn't look like it;
I couldn't find scratch itself in the output, but
./format.go:107:35: digits does not escape
refers to digits argument to fmtE/f functions -- so, no I don't think scratch escapes.
Prefer to use Append and allocate scratch space to improve speed and efficiency of string conversion: ``` name old time/op new time/op delta DecimalString-10 147ns ± 1% 56ns ± 4% -62.14% (p=0.000 n=10+10) name old alloc/op new alloc/op delta DecimalString-10 84.0B ± 0% 39.0B ± 0% -53.57% (p=0.000 n=10+10) name old allocs/op new allocs/op delta DecimalString-10 5.00 ± 0% 1.00 ± 0% -80.00% (p=0.000 n=10+10) ```
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Prefer to use Append and allocate scratch space
to improve speed and efficiency of string conversion: