[PATCH] D27792: IfConversion: Use reverse_iterator to simplify. NFC

Florian Hahn via Phabricator via llvm-commits llvm-commits at lists.llvm.org
Tue Jan 31 15:39:33 PST 2017


fhahn added a comment.

It looks



================
Comment at: lib/CodeGen/IfConversion.cpp:647
+  // We have to do our own shifting so that we get the same range.
+  MachineBasicBlock::reverse_iterator RTIE = std::next(TIE.getReverse());
+  MachineBasicBlock::reverse_iterator RFIE = std::next(FIE.getReverse());
----------------
iteratee wrote:
> dblaikie wrote:
> > This construct is used rather than this:
> > 
> >   MachineBasicBlock::reverse_iterator RTIE = TIE;
> > 
> > to avoid depending on that conversion & it's subtle off-by-one jump?
> Currently, there is no such conversion in ilist_iterator, only a getReverse() method, that doesn't perform an off-by-one jump.
That makes sense. @dblaikie do you think we should check with Duncan before committing this?


https://reviews.llvm.org/D27792





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