[SystemZ] Recognize RISBG opportunities involving a truncate
Summary:
Recognize RISBG opportunities where the end result is narrower than the
original input - where a truncate separates the shift/and operations.
The motivating case is some code in postgres which looks like:
srlg %r2, %r0, 11
nilh %r2, 255
Reviewers: uweigand
Author: RolandF
Differential Revision: http://reviews.llvm.org/D21452
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@273433 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed