[PATCH] D19268: [DAGCombiner] Do not remove the load of stored values when optimizations are disabled

[Quentin Colombet via llvm-commits]

qcolombet added a comment.

Hi,

Does any of the combine done here even make sense for O0?
At first glance, I would say no. In other words, you should be able to exit earlier from this function.

More generally, I believe the problem is widely spread in SDISel and although it is a reasonable approach to fix cases as we encounter them, I think we (will) lack a nice design to fix the problem properly.

Could a start a RFC on llvm-dev about how to block dag combines in O0?

One last comment, please add a test case demonstrating that the combine does not occur at O0 and occurs at O1 and above.

Cheers,
-Quentin


http://reviews.llvm.org/D19268