| commit | 09f3b5ecb16e50d1752dbb57a0d0c3c170dd5537 | [log] [tgz] |
|---|---|---|
| author | Sanjay Patel <spatel@rotateright.com> | Mon Feb 18 23:33:05 2019 +0000 |
| committer | Sanjay Patel <spatel@rotateright.com> | Mon Feb 18 23:33:05 2019 +0000 |
| tree | a84af8312ba07a1c122bb572bbcfaf1f64b83972 | |
| parent | 1e3c4790abc355a619d0c778bfd5f599e5ec2df4 [diff] |
[CGP] form usub with overflow from sub+icmp The motivating x86 cases for forming the intrinsic are shown in PR31754 and PR40487: https://bugs.llvm.org/show_bug.cgi?id=31754 https://bugs.llvm.org/show_bug.cgi?id=40487 ..and those are shown in the IR test file and x86 codegen file. Matching the usubo pattern is harder than uaddo because we have 2 independent values rather than a def-use. This adds a TLI hook that should preserve the existing behavior for uaddo formation, but disables usubo formation by default. Only x86 overrides that setting for now although other targets will likely benefit by forming usbuo too. Differential Revision: https://reviews.llvm.org/D57789 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@354298 91177308-0d34-0410-b5e6-96231b3b80d8