Post-commit feedback for d69c4372bf says the output
may vary between pass managers. This is hopefully a
quick fix, but we might want to investigate how to
better solve this type of problem.
The FileCheck lines in these files are auto-generated and complete,
so there's very little upside (less CHECK lines) from running
-instcombine on them and violating the expected test layering
(optimizer developers shouldn't have to be aware of clang tests).
Running opt passes like this makes it harder to make changes such as:
D93817
Currently, in order to extract an element from a bf16 vector, we cast
the vector to an i16 vector, perform the extraction, and cast the result to
bfloat. This behavior was copied from the old fp16 implementation.
The goal of this patch is to achieve optimal code generation for lane
copying intrinsics in a subsequent patch (LLVM fails to fold certain
combinations of bitcast, insertelement, extractelement and
shufflevector instructions leading to the generation of suboptimal code).
Differential Revision: https://reviews.llvm.org/D82206
Sanjay Patel