[PATCH] D50893: [GVN] Assign new value number to calls reading memory, if there is no MemDep info.

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

PassManagerBuilder supports a boolean DisableGVNLoadPRE, but it looks like it's only hooked up to an actual user option if you're using LTO.  You could add an option to GVN.cpp to override the default, to allow testing this codepath, I guess.



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Comment at: lib/Transforms/Scalar/GVN.cpp:396
     return e;
   } else if (AA->onlyReadsMemory(C)) {
     Expression exp = createExpr(C);
----------------
Probably simpler to check `MD && AA->onlyReadsMemory(C)` here.


https://reviews.llvm.org/D50893