Jonas Paulsson 18a7c886c0 New method SDep::isNormalMemoryOrBarrier() in ScheduleDAGInstrs.cpp. ...

Used to iterate over previously added memory dependencies in
adjustChainDeps() and iterateChainSucc().

SDep::isCtrl() was previously used in these places, that also gave
anti and output edges. The code may be worse if these are followed,
because MisNeedChainEdge() will conservatively return true since a
non-memory instruction has no memory operands, and a false chain dep
will be added. It is also unnecessary since all memory accesses of
interest will be reached by memory dependencies, and there is a budget
limit for the number of edges traversed.

This problem was found on an out-of-tree target with enabled alias
analysis. No test case for an in-tree target has been found.

Reviewed by Hal Finkel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@225351 91177308-0d34-0410-b5e6-96231b3b80d8

2015-01-07 13:38:29 +00:00

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