[PATCH] bug fix for PR20020: anti-dependency-breaker causes miscompilation

[hfinkel at anl.gov]

Can you please upload the patch with more context lines (as explained here: http://llvm.org/docs/Phabricator.html)?

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Comment at: lib/CodeGen/CriticalAntiDepBreaker.cpp:260
@@ +259,3 @@
+      // FIXME: The tied value should already have been checked in
+      // PrescanInstruction(). Do we need to do this check again?
+
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Can you put an assert inside the existing check that the tied registers are in KeepRegs?

http://reviews.llvm.org/D4351