As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
llvm-svn: 358546
This is the last step in getting constant pattern matchers to allow
undef elements in constant vectors.
I'm adding a dedicated m_ZeroInt() function and building m_Zero() from
that. In most cases, calling code can be updated to use m_ZeroInt()
directly when there's no need to match pointers, but I'm leaving that
efficiency optimization as a follow-up step because it's not always
clear when that's ok.
There are just enough icmp folds in InstSimplify that can be used for
integer or pointer types, that we probably still want a generic m_Zero()
for those cases. Otherwise, we could eliminate it (and possibly add a
m_NullPtr() as an alias for isa<ConstantPointerNull>()).
We're conservatively returning a full zero vector (zeroinitializer) in
InstSimplify/InstCombine on some of these folds (see diffs in InstSimplify),
but I'm not sure if that's actually necessary in all cases. We may be
able to propagate an undef lane instead. One test where this happens is
marked with 'TODO'.
llvm-svn: 330550
When checking whether an smin is positive, we can move the comparison to one of the inputs if the other is known positive. If the known positive one is the min, then the other can't be negative. If the other is the min, then we compute the min.
Differential Revision: http://reviews.llvm.org/D17873
llvm-svn: 263059
