[PATCH] D14005: Use the new 'InvariantInfo' property to eliminate redundant loads with --instcombine

[Nick Lewycky via llvm-commits]

nlewycky added a comment.

Patch needs testcases.


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Comment at: lib/Transforms/InstCombine/InstructionCombining.cpp:1961
@@ +1960,3 @@
+
+        // If this is a paired invariant_start, then erase its invariant_end,
+        // and all of its other uses.
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Why bother? We're guaranteed to visit the invariant.start and the invariant.end, right? Just handle invariant_start by replacing it with an undef, and let the generic "EraseInstFromFunction" call (below on line 1975) handle the invariant.end?

I think the other case is an invariant applying to a bitcast instead of to the original object. Does this function work in that case? (Does it even pass isAllocSiteRemovable?)


http://reviews.llvm.org/D14005