[PATCH] Added instruction combine to transform few more negative values addition to subtraction

[Benjamin Kramer]

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Comment at: lib/Transforms/InstCombine/InstCombineAddSub.cpp:929
@@ +928,3 @@
+      C1->getValue() == ~C2->getValue()) {
+    return Builder->CreateAnd(Z, C1);
+  }
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Can you return the fully transformed value? I find it confusing to have this split in half. You can create both instructions with IRBuilder and use ReplaceInstUsesWith at the call site.

http://reviews.llvm.org/D3733