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Kyle Xiao 7ba074fe43 reflect: remove calling mapiterkey, mapiterelem
It makes use of the hiter structure which matches runtime.hiter's.

This change mainly improves the performance of Next method of MapIter.

goos: darwin
goarch: arm64
pkg: reflect
cpu: Apple M2
              │  ./old.txt  │              ./new.txt              │
              │   sec/op    │   sec/op     vs base                │
MapIterNext-8   61.95n ± 0%   54.95n ± 0%  -11.28% (p=0.000 n=10)

for the change of `test/escape_reflect.go`:
removing mapiterkey, mapiterelem would cause leaking MapIter content
when calling SetIterKey and SetIterValue,
and this may cause map bucket to be allocated on heap instead of stack.
Reproduce:
```
{
  m := map[int]int{1: 2} // escapes to heap after this change
  it := reflect.ValueOf(m).MapRange()
  it.Next()
  var k, v int
  reflect.ValueOf(&k).Elem().SetIterKey(it)
  reflect.ValueOf(&v).Elem().SetIterValue(it)
  println(k, v)
}
```
This CL would not introduce abi.NoEscape to fix this. It may need futher
optimization and tests on hiter field usage and its escape analysis.

Fixes #69416

Change-Id: Ibaa33bcf86228070b4a505b9512680791aa59f04
Reviewed-on: https://go-review.googlesource.com/c/go/+/612616
Reviewed-by: Keith Randall <khr@golang.org>
Auto-Submit: Keith Randall <khr@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Keith Randall <khr@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
2024-09-18 20:57:20 +00:00
.github .github: update language change proposal template 2024-08-08 19:02:29 +00:00
api net/http: add HTTP2Config 2024-08-29 17:38:46 +00:00
doc encoding/json: add embedded structs to the UnmarshalTypeError's Field 2024-09-03 15:49:47 +00:00
lib misc/wasm: move wasm runtime files to lib/wasm 2024-08-30 19:15:21 +00:00
misc misc/wasm: move wasm runtime files to lib/wasm 2024-08-30 19:15:21 +00:00
src reflect: remove calling mapiterkey, mapiterelem 2024-09-18 20:57:20 +00:00
test reflect: remove calling mapiterkey, mapiterelem 2024-09-18 20:57:20 +00:00
.gitattributes all: treat all files as binary, but check in .bat with CRLF 2020-06-08 15:31:43 +00:00
.gitignore runtime,internal: move runtime/internal/sys to internal/runtime/sys 2024-07-23 19:05:35 +00:00
codereview.cfg codereview.cfg: add codereview.cfg for master branch 2021-02-19 18:44:53 +00:00
CONTRIBUTING.md doc: normalize proposal-process links 2023-03-29 22:00:27 +00:00
go.env cmd/go: additional doc-inspired tests and bug fixes 2023-06-06 19:18:46 +00:00
LICENSE LICENSE: update per Google Legal 2024-08-09 14:54:31 +00:00
PATENTS LICENSE: separate, change PATENTS text 2010-12-06 16:31:59 -05:00
README.md README: fix CC BY license name 2024-07-22 17:45:27 +00:00
SECURITY.md SECURITY.md: update the Reporting a Vulnerability link 2023-09-22 21:17:24 +00:00

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