Re: [Tarantool-patches] [PATCH luajit] Fix TDUP load forwarding after table rehash.

[Igor Munkin via Tarantool-patches <tarantool-patches@dev.tarantool.org>]

Sergey,

I've checked the patchset into all long-term branches in
tarantool/luajit and bumped a new version in master, release/2.11 and
release/2.10.

On 17.08.23, Sergey Kaplun via Tarantool-patches wrote:
> From: Mike Pall <mike>
> 
> Reported by Sergey Kaplun.
> 
> (cherry-picked from commit c7db8255e1eb59f933fac7bc9322f0e4f8ddc6e6)
> 
> After table rehashing number keys loaded via ALOAD may be placed in the
> hash part of the table. So, load forwarding analysis missed the
> corresponding stores like they are never existed. In such case, either
> we faced an assertion failure in `fwd_ahload()` due to values types
> mismatch, either we faced an assertion failure in `rec_check_slots()`
> since forwarded value by the JIT compiler isn't the same as it is in the
> interpreter.
> 
> This patch adds a check that there is no any `IR_NEWREF` after table
> creation, so it can't be rehashed.
> 
> Sergey Kaplun:
> * added the description and the test for the problem
> 
> Part of tarantool/tarantool#8825
> ---
> 
> Branch: https://github.com/tarantool/luajit/tree/skaplun/lj-980-load-fwd-after-table-rehash
> PR: https://github.com/tarantool/tarantool/pull/8998
> Related issues:
> * https://github.com/LuaJIT/LuaJIT/issues/980
> * https://github.com/tarantool/tarantool/issues/8825
> 
>  src/lj_opt_mem.c                              |   6 +
>  ...j-980-load-fwd-after-table-rehash.test.lua | 166 ++++++++++++++++++
>  2 files changed, 172 insertions(+)
>  create mode 100644 test/tarantool-tests/lj-980-load-fwd-after-table-rehash.test.lua
> 

<snipped>

> -- 
> 2.41.0
> 

-- 
Best regards,
IM