[PATCH] D12588: PeepholeOptimizer: Look through simple extracts of reg_sequence

[Quentin Colombet via llvm-commits]

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Hi Matt,

The changes in the peephole optimizer and AMDGPU seem to be to separate patches to me.
Please stage them like that if this is indeed the case.

Also, the thing that you add to the rewriter does not fit with the intended design, see inline comments.

Cheers,
-Quentin


================
Comment at: lib/CodeGen/PeepholeOptimizer.cpp:1252
@@ +1251,3 @@
+  //
+  //  => vreg3 = COPY vreg0
+  //
----------------
The design of the copy rewriter is to find alternative sources within the value tracker.
This change does not fit that scheme and looks like an ad hoc solution.
I believe what it is missing is to teach the value tracker about sub register.
Could you look into that direction or explain why do you think we should do it like you propose in this patch?


http://reviews.llvm.org/D12588