[PATCH] D11434: Allow value forwarding past release fences in EarlyCSE

JF Bastien via llvm-commits llvm-commits at lists.llvm.org
Wed Aug 26 16:01:01 PDT 2015


jfb added inline comments.

================
Comment at: lib/Transforms/Scalar/EarlyCSE.cpp:617
@@ +616,3 @@
+    // A release fence requires that all stores complete before it, but does
+    // not prevent the reordering of following loads 'before' the fence.  As a
+    // result, we don't need to consider it as writing to memory and don't need
----------------
Getting re-acquainted with the code: it doesn't seem like this change exercises a test?

================
Comment at: test/Transforms/EarlyCSE/fence.ll:59
@@ +58,3 @@
+; We can not dead store eliminate accross the fence.  We could in 
+; principal reorder the second store above the fence and then DSE either
+; store, but this is beyond the simple last-store DSE which EarlyCSE
----------------
principle


http://reviews.llvm.org/D11434





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