[PATCH] D15138: Disable signbit related bitcast optimization for ppc_fp128

[hfinkel@anl.gov via llvm-commits]

hfinkel requested changes to this revision.
hfinkel added a comment.
This revision now requires changes to proceed.

In http://reviews.llvm.org/D15138#301080, @timshen wrote:

> The code generation for ppc_fp128 better, since it's originally wrong and now correct. Changed checks to pin down the exact correct behavior.


One of the things that I really like about working on LLVM is that It is the general philosophy of this project not to simply disable optimizations in otherwise-broken corner cases, but to properly fix them. Obviously this is not always practical, but it certainly is in this case.

Please prototype a fix which generates the correct mask for ppc_fp128 and compare the resulting code quality. If you don't wish to do this, please let me know, and I (or someone else who works on PowerPC here) will do it for you.

Also, please upload your patches with full context. See http://llvm.org/docs/Phabricator.html#requesting-a-review-via-the-web-interface for instructions.


Repository:
  rL LLVM

http://reviews.llvm.org/D15138