[PATCH] D14902: [AArch64] Promote loads from stored

[Meador Inge via llvm-commits]

meadori added a subscriber: meadori.

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Comment at: lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp:1552
@@ +1551,3 @@
+  // 1) Find a load that directly reads from stored and replace it with
+  //    a bitfield instruction.
+  //      e.g.,
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This isn't completely accurate.  In some cases the store is replaced with a move.  I read this comment first and was surprised to find the move case in the actual code.

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Comment at: test/CodeGen/AArch64/arm64-ld-from-st.ll:603
@@ +602,2 @@
+}
+
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I see lots of good tests to verify that the optimization happens, but I don't see any to verify cases where it should *not* happen (e.g. the volatile case, modified registers, in range, across calls, etc...).  The negative cases are just as important to verify as the positive ones.


http://reviews.llvm.org/D14902