A profile annotates a function only while its control flow hashes as it did
when the profile was collected, so compiler and source changes leave the
changed functions without counts. A --profile-use build now reads a
block-count file beside the profile (app.blocks beside app.profdata). Right
after the annotation before inlining, the helper aligns each uncounted
function's blocks with its recorded blocks by label kind and successor
count. Paired blocks take their recorded counts and their edges the recorded
edge counts, by target or, between targets whose labels changed, by
position. LLVM's flow inference fills in the rest, avoiding the edges the
function's own llvm.expect weights make unlikely. The helper then sets the
entry count, branch weights and hot or cold attribute as the profile
annotation does.
SCRIPTC_RECORD_PROFILE_BLOCKS names the file a --profile-use build writes
for the functions its profile annotates; such a build reuses no cached
artifacts. The block file keys every cache, the build report counts the
functions it annotated, and the staleness warning counts only the functions
left without counts. A single-module build with a context-sensitive profile
no longer counts annotated, mismatched and missing functions a second time
after inlining. scripts/refresh-cli-profile.mjs records the file in the
second phase and build-native-cli.mts reads it beside the profile.
`scripts/refresh-cli-profile.mjs --context-sensitive` runs the training twice. The second run uses a compiler that the first profile optimizes and that is instrumented again after inlining, and it merges those counts into the first profile. Builds with the result also order each function's blocks by the counts and split cold blocks off (context-sensitive profiles). `--base-profile` runs only the second phase. `scripts/build-native-cli.mts` builds such a compiler when `SCRIPTC_NATIVE_PROFILE_GENERATE` and `SCRIPTC_NATIVE_PROFILE_USE` are both set. The release workflow's cli-profile job collects the profile this way, with a 120-minute timeout.
Parallel changes kept taking the same next corpus number (6992 twice, the
Node island programs renumbered several times). The harness never needed
the numbers: it discovers every entry by glob, and 818 programs already
have descriptive names. AGENTS.md now makes a name, without a number, the
convention for new programs and keeps the numbered ones as they are.
The two scripts that sampled programs by number skipped named programs.
They now key a named program by a stable hash of its name, so they sample
it at the same rate; the numbered programs they pick are unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The release workflow's new cli-profile job runs
scripts/refresh-cli-profile.mjs on Linux x64 and uploads the profile.
Every platform's native CLI build uses it through
SCRIPTC_NATIVE_PROFILE_USE, and the GitHub release attaches it as
scriptc-<version>-cli.profdata.gz. When the job fails, the CLI builds
use the committed profile.
build-native-cli.mts accepts a gzip-compressed profile in
SCRIPTC_NATIVE_PROFILE_USE when the name ends in .gz.
refresh-cli-profile.mjs creates the directory of --output before it
starts.
Chris Tate