[PATCH] D89739: [LCSSA] Doc for special treatment of PHIs

[Stefanos Baziotis via Phabricator via llvm-commits]

baziotis added inline comments.


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Comment at: llvm/docs/LoopTerminology.rst:457
 
+.. [#point-of-use-phis] Considering the point of use of a PHI entry value
+  to be in the respective predecessor is a convention across the whole LLVM.
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Hopefully the combination of this footnote with the last changes is a good result. First of all, it's not the place of the LCSSA doc to explain why the rest of LLVM uses this convention, yet I think this footnote adds value. Second, now the text above I think is clear in what happens with the usages in PHIs: both definition is referenced and convention is explained. Please let me know what you think.


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Comment at: llvm/docs/LoopTerminology.rst:461-465
+  liveness: A value is live up to the predecessor block because it
+  can't be used from the PHI and onwards (otherwise the PHI would not
+  be needed in the first place). Effectively, the PHI kills the incoming
+  value(s) and replaces them with a new definition.
+
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This comment about liveness helps me very much understand this convention, I hope I have understood it's on point.


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https://reviews.llvm.org/D89739