[PATCH] DAGCombiner: Continue combining if FoldConstantArithmetic() fails.

[Matthias Braun]

> Ah, indeed. Shouldn't the rule be: Don't fold an opaque constant into another constant unless he result is cheap or free (in the getIntImmConst sense)?


Yes. In fact I did not bother to guard a few combines that produce a zero result, though admittedly the code does not check whether zero is an expensive constant - but I can't imagine that to be the case on any target.

Anyway I'm currently adapting the patch to ToT and will try out RKSimons suggestion which will probably simplify this a lot.


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