mirror of
https://github.com/RPCS3/llvm.git
synced 2026-07-21 03:05:26 -04:00
Roman Lebedev
9c6c87791d
Summary: While `-div-rem-pairs` pass can decompose rem in div+rem pair when div-rem pair is unsupported by target, nothing performs the opposite fold. We can't do that in InstCombine or DAGCombine since neither of those has access to TTI. So it makes most sense to teach `-div-rem-pairs` about it. If we matched rem in expanded form, we know we will be able to place div-rem pair next to each other so we won't regress the situation. Also, we shouldn't decompose rem if we matched already-decomposed form. This is surprisingly straight-forward otherwise. The original patch was committed in rL367288 but was reverted in rL367289 because it exposed pre-existing RAUW issues in internal data structures of the pass; those now have been addressed in a previous patch. https://bugs.llvm.org/show_bug.cgi?id=42673 Reviewers: spatel, RKSimon, efriedma, ZaMaZaN4iK, bogner Reviewed By: bogner Subscribers: bogner, hiraditya, llvm-commits Tags: #llvm Differential Revision: https://reviews.llvm.org/D65298 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@367419 91177308-0d34-0410-b5e6-96231b3b80d8