fix a -Wdocumentation warning.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199113 91177308-0d34-0410-b5e6-96231b3b80d8
[SystemZ] Optimize (sext (ashr (shl ...), ...))

...into (ashr (shl (anyext X), ...), ...), which requires one fewer
instruction.  The (anyext X) can sometimes be simplified too.

I didn't do this in DAGCombiner because widening shifts isn't a win
on all targets.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199114 91177308-0d34-0410-b5e6-96231b3b80d8
[SystemZ] Improve risbg-01.ll test

The old mask in f24 wasn't well chosen because the lshr would always be zero.
CodeGen didn't detect this but InstCombine would.  The new mask ensures
that both shifts are needed.

f26 is specifically testing for a wrap-around mask.  The AND can be applied
to just the shift left, either before or after the shift.  Again, CodeGen
kept it in the original form but InstCombine would mask after the shift
instead.  The exact choice of NILF isn't important for the test so I just
dropped it and kept the rotate.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199115 91177308-0d34-0410-b5e6-96231b3b80d8
[SystemZ] Add "volatile" to a dead store in variable-loc.ll


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199116 91177308-0d34-0410-b5e6-96231b3b80d8
[SystemZ] Flesh out stackrestore test (frame-11.ll)

...so that it does something vaguely sensible.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199117 91177308-0d34-0410-b5e6-96231b3b80d8
Fix indentation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199118 91177308-0d34-0410-b5e6-96231b3b80d8