[PATCH] D12656: PR 23155: Change test to allow movzbl, movzwl in place of movb, movw instructions

[Kevin B. Smith via llvm-commits]

kbsmith1 added a comment.

There are a handful (6-8) tests that currently are checking for movw, where either movzwl or movw would be legal choices. There are quite a few more that specifically expect movb where movzbl would also be legal.  My intent was to add a test that tested for the specific movb vs movzbl or movw vs movzwl when the transformations to change these opcodes got added.

My intent with this change-set was to get started changing tests where the test wasn't specifically trying to test ffor  one or the other, where the test was simply testing for what the compiler currently did, rather than what it was legal to do.  It seems like the principal of these unit tests should be to accept all legal outputs, except for the key place where they were checking for a specific piece of the implementation.  That way the tests are not so fragile as heuristic changes are made.  It seems wrong to have so many tests dependent on this choice, when that is really tangential to what they seem to be intending to check.

I was doing this to try to make these changes in small, easy to review pieces.


http://reviews.llvm.org/D12656