Commit Graph

4 Commits

Author SHA1 Message Date
Chris Lattner
8114b718c9 make truncate/sext elimination capable of changing phi's. This
implements rdar://6013816 and the testcase in Transforms/InstCombine/sext-misc.ll.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52440 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-18 04:00:49 +00:00
Dan Gohman
7a9708b984 Oops, commit the version of this test that actually works.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51351 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 21:19:36 +00:00
Dan Gohman
f35c8822a3 Port SelectionDAG's ComputeNumSignBits-using code to instcombine,
now that instcombine also has ComputeNumSignBits.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51350 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 21:01:12 +00:00
Dan Gohman
23e8b71526 Teach InstCombine's ComputeMaskedBits what SelectionDAG's
ComputeMaskedBits knows about cttz, ctlz, and ctpop. Teach
SelectionDAG's ComputeMaskedBits what InstCombine's knows
about SRem. And teach them both some things about high bits
in Mul, UDiv, URem, and Sub. This allows instcombine and
dagcombine to eliminate sign-extension operations in
several new cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50358 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-28 17:02:21 +00:00