Hi!
Thanks for the patch!
LGTM, except for a few nits below.
> 
>>From: Mike Pall <mike>
>>
>>Analyzed by Sergey Kaplun.
>>
>>(cherry-picked from commit a01cba9d2d74efc57376822aa43db2d5043af5a4)
>>
>>This patch is the follow-up for the previous one. It removes the
>Typo: s/the/a
>Typo: s/for the/to the/
>>condition for `maxslot` changing in the case when varargs are defined
>>on the trace (i.e. `framedepth` > 0).
>Typo: s/i.e./i.e.,/
>>
>>Sergey Kaplun:
>>* added the description and the test for the problem
>>
>>Part of tarantool/tarantool#8825
>>---
>> src/lj_record.c | 8 ++------
>> .../lj-1024-varg-maxslot.test.lua | 19 ++++++++++++++++++-
>> 2 files changed, 20 insertions(+), 7 deletions(-)
>>
>>diff --git a/src/lj_record.c b/src/lj_record.c
>>index 112524d3..02d9db9e 100644
>>--- a/src/lj_record.c
>>+++ b/src/lj_record.c
>>@@ -1775,12 +1775,8 @@ static void rec_varg(jit_State *J, BCReg dst, ptrdiff_t nresults)
>>   if (J->framedepth > 0) { /* Simple case: varargs defined on-trace. */
>>     ptrdiff_t i;
>>     if (nvararg < 0) nvararg = 0;
>>- if (nresults == -1) {
>>- nresults = nvararg;
>>- J->maxslot = dst + (BCReg)nvararg;
>>- } else if (dst + nresults > J->maxslot) {
>>- J->maxslot = dst + (BCReg)nresults;
>>- }
>>+ if (nresults == -1) nresults = nvararg;
>>+ J->maxslot = dst + (BCReg)nresults;
>>     for (i = 0; i < nresults; i++)
>>       J->base[dst+i] = i < nvararg ? getslot(J, i - nvararg - 1 - LJ_FR2) : TREF_NIL;
>>   } else { /* Unknown number of varargs passed to trace. */
>>diff --git a/test/tarantool-tests/lj-1024-varg-maxslot.test.lua b/test/tarantool-tests/lj-1024-varg-maxslot.test.lua
>>index 14270595..f8d74e8a 100644
>>--- a/test/tarantool-tests/lj-1024-varg-maxslot.test.lua
>>+++ b/test/tarantool-tests/lj-1024-varg-maxslot.test.lua
>>@@ -3,7 +3,7 @@ local test = tap.test('lj-noticket-varg-usedef'):skipcond({
>>   ['Test requires JIT enabled'] = not jit.status(),
>> })
>> 
>>-test:plan(1)
>>+test:plan(2)
>> 
>> jit.opt.start('hotloop=1')
>> 
>>@@ -20,4 +20,21 @@ end
>> 
>> test:ok(true, 'BC_VARG recording 0th frame depth')
>> 
>>+-- Now the same case, but with additional frame, so VARG slots
>Typo: s/with/with an/
>>+-- are defined on the trace.
>>+local function bump_varg_frame(...)
>Nit: Not sure about the name here, maybe it is better to call it
>just `varg_frame` or something like that. Feel free to ignore, though.
>>+ -- BC_VARG 1 1 0. `...` is nil (argument for the script).
>>+ -- luacheck: ignore
>>+ -- XXX: some condition to use several slots on the Lua stack.
>>+ anchor = 1 >= 1, ...
>>+end
>>+
>>+counter = 0
>>+while counter < 3 do
>>+ counter = counter + 1
>>+ bump_varg_frame()
>>+end
>>+
>>+test:ok(true, 'BC_VARG recording with defined on trace VARG slots')
>>+
>> os.exit(test:check() and 0 or 1)
>>--
>>2.34.1
>--
>Best regards,
>Maxim Kokryashkin
>