Chris Tate 396c6944ec Report how well the native compiler's profile matches its functions ...

The native compiler is built with a committed optimization profile. A
function whose control flow changed since the profile was collected is
optimized as without one, so the profile loses its gain as compiler code
changes, with nothing to show it.

With --profile-use, the helper now counts what the profile annotation
reports while it applies the profile: functions that took the profile's
counts, functions whose control flow no longer matches (hash mismatch),
and functions the profile has no record of. It sums the counts over
partitions, keeps each partition's counts beside its cached summary, and
prints them as one line of JSON after a successful emit. The compiler
reads that line (an older helper prints none) and returns it as the
executable artifact's profileMatch.

build-native-cli prints the share of profiled functions that match, and
warns below 90% that the profile should be refreshed. On main aa1c26845, a
profile refreshed on that commit matches 92.7% of the compiler's profiled
functions, and the one committed about 200 commits earlier 87.2%; that one
kept about half of the fresh profile's gain on a cold tsc-ts build.

2026-10-24 11:20:47 -05:00

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llvm-codegen

Report how well the native compiler's profile matches its functions

2026-10-24 11:20:47 -05:00