Per https://llvm.org/docs/CodingStandards.html#include-as-little-as-possible this improves compilation time, while not being too intrusive on the codebase.
This extends the DropUnnecessaryAssumes pass to also handle operand bundle assumes. For this purpose, export the affected value analysis for operand bundles from AssumptionCache. If the bundle only affects ephemeral values, drop it. If all bundles on an assume are dropped, drop the whole assume.
ResultElem stores a weak handle of an assume, plus an index for referring to a specific operand bundle. This makes sense for the results of assumptionsFor(), which refers to specific operands of assumes. However, assumptions() is a plain list of assumes. It does *not* contain separate entries for each operand bundles. The operand bundle index is always ExprResultIdx. As such, we should be directly using WeakVH for this case, without the additional wrapper.
- Do not call pass initialization from pass constructors. - Instead, pass initialization should happen in the `initializeAnalysis` function. - https://github.com/llvm/llvm-project/issues/111767
Add the underlying object of both separate_storage arguments as affected values. This allows us to use assumptionsFor() in BasicAA, which will be more efficient if there are many assumes in the function.
We only handle not for the top level value of the condition, so move it there instead of trying to look through not at all leafs. Also remove bitcast handling entirely -- we don't do anything special wrt bitcasts, this is probably a leftover from pointer types.
For most practical purposes, the only KnownBits patterns we care about are those involving a constant comparison RHS and constant mask. However, the actual implementation is written in a very general way -- and of course, with basically no test coverage of those generalizations. This patch reduces the implementation to only handle cases with constant operands. The test changes are all in "make sure we don't crash" tests. The motivation for this change is an upcoming patch to handling dominating conditions in computeKnownBits(). Handling non-constant RHS would add significant additional compile-time overhead in that case, without any significant impact on optimization quality.
For all practical purposes, we only care about comparisons with constant RHS in this code. In that case, an invert will be canonicalized into the constant and it will be handled by other cases. Given the complete lack of test coverage, I'm removing this code.