Andrea Faulds f497fe464b
[mlir][spirv] Fix some issues related to converting ub.poison to SPIR-V (#125905)
This is a follow-up to 5df62bdc9be9c258c5ac45c8093b71e23777fa0e. That
commit should not have needed to make the vector.insert and
vector.extract conversions to SPIR-V directly handle the static poison
index case, as there is a fold from those to ub.poison, and a conversion
pattern from ub.poison to spirv.Undef, however:

- The ub.poison fold result could not be materialized by the vector
dialect (fixed as of d13940ee263ff50b7a71e21424913cc0266bf9d4).
- The conversion pattern wasn't being populated in VectorToSPIRVPass,
which is used by the tests. This commit changes this.
- The ub.poison to spirv.Undef pattern rejected non-scalar types, which
prevented its use for vector results. It is unclear why this restriction
existed; a remark in D156163 said this was to avoid converting "user
types", but it is not obvious why these shouldn't be permitted (the
SPIR-V specification allows OpUndef for all types except OpTypeVoid).
This commit removes this restriction.

With these fixed, this commit removes the redundant static poison index
handling, and updates the tests.
2025-02-06 19:07:34 +01:00
..