tor-browser

commit 8d41135430152398012691936d1e53fe0b828b64
parent 36cc61c456916815a73b70ac3d308dfbb183f1c2
Author: serge-sans-paille <sguelton@mozilla.com>
Date:   Wed, 10 Dec 2025 10:36:25 +0000

Bug 2005140 - Activate BOLT post-link optimization for clang-21 r=glandium

Without bolt:

% hyperfine './clang/bin/clang -w -c -O2 ~/sources/sqlite-bench/sqlite3.c'
Benchmark 1: ./clang/bin/clang -w -c -O2 ~/sources/sqlite-bench/sqlite3.c
  Time (mean ± σ):     10.972 s ±  0.029 s    [User: 10.854 s, System: 0.057 s]
  Range (min … max):   10.902 s … 11.014 s    10 runs

With bolt:

% hyperfine './clang/bin/clang -w -c -O2 ~/sources/sqlite-bench/sqlite3.c'
Benchmark 1: ./clang/bin/clang -w -c -O2
~/sources/sqlite-bench/sqlite3.c
  Time (mean ± σ):     10.474 s ±  0.102 s    [User: 10.352 s, System: 0.060 s]
  Range (min … max):   10.323 s … 10.593 s    10 runs

That's ~4% faster, nothing to be frowned upon.

Differential Revision: https://phabricator.services.mozilla.com/D275739

Diffstat:
M
taskcluster/kinds/toolchain/clang.yml
 | 
2
++

1 file changed, 2 insertions(+), 0 deletions(-)
diff --git a/taskcluster/kinds/toolchain/clang.yml b/taskcluster/kinds/toolchain/clang.yml
@@ -849,10 +849,12 @@ linux64-clang-21-raw:
             - 'build/build-clang/use-clang-artifact.json'
             - 'build/build-clang/clang-21.json'
             - 'build/build-clang/stage-4-pgo.json'
+            - 'build/build-clang/stage-4-bolt.json'
         resources:
             - 'build/build-clang/use-clang-artifact.json'
             - 'build/build-clang/clang-21.json'
             - 'build/build-clang/stage-4-pgo.json'
+            - 'build/build-clang/stage-4-bolt.json'
         toolchain-artifact: public/build/clang.tar.zst
     fetches:
         fetch: