[llvm] [CodeGen] Fixed vector halving bug for masked load

Authored by aartbik on Apr 23 2020, 11:28 AM.


[llvm] [CodeGen] Fixed vector halving bug for masked load

Given a VL=14 that is enveloped by a proper VL=16, splitting the
masked load using the enveloping halving VL=8/8 should yields
should eventually yield V=8/5. This fixes various assert failures
in getHalfNumVectorElementsVT() and IncrementMemoryAddress().

Note, I suspect similar fixes will be needed for other masked
operations, but for now I send out a fix for masked load only.

Bugzilla issue 45563

Reviewers: craig.topper, mehdi_amini, nicolasvasilache

Reviewed By: craig.topper

Subscribers: hiraditya, dmgreen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D78608