tarantool / luajit / 7043426970

89%

tarantool/master: 93%

Build Type

push

github

Committed by Buristan

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

Coverage Stats

5374 of 5986 branches covered (0.0%)

Branch coverage included in aggregate %.

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

2 existing lines in 1 file now uncovered.

20610 of 23355 relevant lines covered (88.25%)

2750732.4 hits per line