PreRA scheduler should avoid cloning compares.
authorAndrew Trick <atrick@apple.com>
Thu, 1 Sep 2011 00:54:31 +0000 (00:54 +0000)
committerAndrew Trick <atrick@apple.com>
Thu, 1 Sep 2011 00:54:31 +0000 (00:54 +0000)
commit340d78f4e7b95c235d0ecf315b755bebefd0a168
treea0ff341ce5176af908e04964c54395010f291a87
parent35726bfcaa852fcbcbda03613b7f9a59763003bc
PreRA scheduler should avoid cloning compares.

Added canClobberReachingPhysRegUse() to handle a particular pattern in
which a two-address instruction could be forced to interfere with
EFLAGS, causing a compare to be unnecessarilly cloned.
Fixes rdar://problem/5875261

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138924 91177308-0d34-0410-b5e6-96231b3b80d8
lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
test/CodeGen/X86/2008-01-08-SchedulerCrash.ll