Open Bug 1516842 Opened 2 years ago Updated 2 years ago

disable -fdata-sections and -ffunction-sections for LTO builds

Categories

(Firefox Build System :: General, enhancement)

66 Branch
enhancement
Not set
normal

Tracking

(Not tracked)

UNCONFIRMED

People

(Reporter: jh, Unassigned)

Details

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:66.0) Gecko/20100101 Firefox/66.0

Steps to reproduce:

-fdata-sections and -ffunction-sections was added to enable unreachable code and identical code folding in linker. They however have additional overhead by extra padding at the section boundary and link-time overhead.

With -fno-lto these save about 8MB of binary for Clang build and 5MB for GCC build. With -flto I get only small size increase.

with sections
https://treeherder.mozilla.org/#/jobs?repo=try&revision=cc95b0d31e990fc1072a68fb3fc0fcdcf3d4074c&selectedJob=219244560
with no sections
https://treeherder.mozilla.org/#/jobs?repo=try&revision=4017ed21216daed72939a3c1179185ec34921060&selectedJob=219250182
Component: Untriaged → General
Product: Firefox → Firefox Build System

Per conversation with :kmoir, I'm going through untriaged bugs in her components and marking the ones which look to be enhancements/tasks with the enhancement severity to get them out of the triage queue.

If this incorrect, please remove the tag.

Severity: normal → enhancement
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