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| author | Björn Gustavsson <bjorn@erlang.org> | 2023-01-18 16:18:25 +0100 |
|---|---|---|
| committer | Björn Gustavsson <bjorn@erlang.org> | 2023-01-19 06:27:42 +0100 |
| commit | 03323f3959006332d6ba8d82dc4f1ad41e9e8725 (patch) | |
| tree | 3ed607fe58d2f76942ef17bd577b34c2e370b7bf /erts/emulator/beam | |
| parent | 6fe1996af121986b6f402d1c0282387c3d8a4b8f (diff) | |
| download | erlang-03323f3959006332d6ba8d82dc4f1ad41e9e8725.tar.gz | |
non-JIT BEAM: Avoid redundant GC in binary syntax
In the binary syntax, avoid doing a garbage collection when matching
out an integer if the match is known to fail because the binary is
too short. This test is already done in the JIT.
Diffstat (limited to 'erts/emulator/beam')
| -rw-r--r-- | erts/emulator/beam/emu/bs_instrs.tab | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/erts/emulator/beam/emu/bs_instrs.tab b/erts/emulator/beam/emu/bs_instrs.tab index c8bba1e70a..846e4b6f2c 100644 --- a/erts/emulator/beam/emu/bs_instrs.tab +++ b/erts/emulator/beam/emu/bs_instrs.tab @@ -1404,10 +1404,19 @@ bs_get_integer.head() { bs_get_integer.fetch(Ctx, Size, Live) { Uint wordsneeded; + ErlBinMatchBuffer* mb; Ms = $Ctx; Sz = $Size; wordsneeded = 1+WSIZE(NBYTES(Sz)); - $GC_TEST_PRESERVE(wordsneeded, $Live, Ms); + + /* Check bits size before potential GC. We do not want a GC + * and then realize we don't need the allocated space (if the + * op fails). + */ + mb = ms_matchbuffer(Ms); + if (mb->size - mb->offset >= Sz) { + $GC_TEST_PRESERVE(wordsneeded, $Live, Ms); + } } bs_get_integer.fetch_small(Ctx, Size) { |