tarantool / luajit / 7118518838

93%

Build Type

push

github

Committed by igormunkin

Commit Message

Prevent CSE of a REF_BASE operand across IR_RETF.

Reported by XmiliaH.

(cherry-picked from commit e73916d81)

The RETF IR has a side effect: it shifts base when returning to a lower
frame, i.e., it affects `REF_BASE` IR (0000) (thus, we can say that this
IR is violating SSA form). So any optimization of IRs with `REF_BASE` as
an operand across RETF IR may lead to incorrect optimizations (see
details in the test file).

This patch adds rules to the folding engine to prevent CSE across `IR_RETF`
for all possible IRs containing REF_BASE.

Sergey Kaplun:
* added the description and the test for the problem

Part of tarantool/tarantool#9145

Reviewed-by: Sergey Bronnikov <sergeyb@tarantool.org>
Reviewed-by: Maxim Kokryashkin <m.kokryashkin@tarantool.org>
Signed-off-by: Igor Munkin <imun@tarantool.org>

Run Details

5375 of 5986 branches covered (0.0%)

Branch coverage included in aggregate %.

2 of 2 new or added lines in 1 file covered. (100.0%)

8 existing lines in 2 files now uncovered.

20619 of 23355 relevant lines covered (88.29%)

2746398.45 hits per line