[go] cmd/link: avoid per-comparison loader calls in STYPE sort in dodata

0 views

Skip to first unread message

Gopher Robot (Gerrit)

unread,

Apr 14, 2026, 6:48:50 PM (16 hours ago) Apr 14

to Pierre Gimalac, goph...@pubsubhelper.golang.org, golang-...@googlegroups.com, Ian Lance Taylor, Mark Freeman, David Chase, Cherry Mui, golang...@luci-project-accounts.iam.gserviceaccount.com, Michael Hudson-Doyle, Russ Cox, golang-co...@googlegroups.com

Gopher Robot submitted the change

Change information

Commit message:

cmd/link: avoid per-comparison loader calls in STYPE sort in dodata

The sort comparison function for STYPE symbols calls ldr.IsItab (which
dispatches through the loader into packed object file data) twice per
comparison and looks up a map for the type string on every call.

Pre-compute isItab, isTypelink, and typeStr into the symNameSize struct
alongside the existing sz field in a single linear pass before the sort.
The comparison function and the post-sort boundary loops then do only
struct field reads.

Measured the `dodata` phase when linking a large CGO binary
(github.com/DataDog/datadog-agent/cmd/agent) using `-benchmark=cpu`:

      go1.26.2: 207ms, 205ms, 206ms
      tip:      714ms, 702ms, 700ms
      tip+fix:  325ms, 325ms, 333ms

Fixes #78642.

Change-Id: I4c1e3acc1c57b8c31441e6b6485debb0cce9b197

Reviewed-on: https://go-review.googlesource.com/c/go/+/765700

Reviewed-by: Ian Lance Taylor <ia...@golang.org>

Reviewed-by: Mark Freeman <markf...@google.com>

LUCI-TryBot-Result: golang...@luci-project-accounts.iam.gserviceaccount.com <golang...@luci-project-accounts.iam.gserviceaccount.com>

Auto-Submit: Ian Lance Taylor <ia...@golang.org>

Reviewed-by: David Chase <drc...@google.com>

Files:

M src/cmd/link/internal/ld/data.go

Change size: S

Delta: 1 file changed, 25 insertions(+), 16 deletions(-)

Branch: refs/heads/master

Submit Requirements:

Code-Review: +2 by Ian Lance Taylor, +1 by David Chase, +1 by Mark Freeman
TryBots-Pass: LUCI-TryBot-Result+1 by golang...@luci-project-accounts.iam.gserviceaccount.com

Open in Gerrit

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

open

diffy

satisfied_requirement

Reply all

Reply to author

Forward

0 new messages