Commit Graph

3 Commits

Author SHA1 Message Date
Dan Gohman
15cab2817b Back out the change in 64918 that used sign-extensions when promoting
trip counts that use signed comparisons. It's not obviously the best
approach for preserving trip count information, and at any rate there
isn't anything in the tree right now that makes use of that, so for
now always using zero-extensions is preferable.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@65347 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-23 23:20:35 +00:00
Dan Gohman
f5a309e989 Use a sign-extend instead of a zero-extend when promoting a
trip count value when the original loop iteration condition is
signed and the canonical induction variable won't undergo signed
overflow. This isn't required for correctness; it just preserves
more information about original loop iteration values.

Add a getTruncateOrSignExtend method to ScalarEvolution,
following getTruncateOrZeroExtend.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64918 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-18 17:22:41 +00:00
Dan Gohman
74786c0f43 Rename IndVarsSimplify to IndVarSimplify, to be consistent with
the name used in the code that these tests are for.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64624 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-16 00:56:15 +00:00