[SystemZ] Provide improved cost estimates (#83873)

This commit provides better cost estimates for
the llvm.vector.reduce.add intrinsic on SystemZ. These apply to all
vector lengths and integer types up to i128. For integer types larger
than i128, we fall back to the default cost estimate.

This has the effect of lowering the estimated costs of most common
instances of the intrinsic. The expected performance impact of this is
minimal with a tendency to slightly improve performance of some
benchmarks.

This commit also provides a test to check the proper computation of the
new estimates, as well as the fallback for types larger than i128.

0 files changed, 0 insertions, 0 deletions