[PATCH] Refactor reciprocal square root estimate into target-independent function (part 1).

[Sanjay Patel]

================
Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:7012-7014
@@ -7007,1 +7011,5 @@
+    // it may be folded into a target-specific square root estimate intruction.
+    SDValue SqrtOp = BuildRSQRTE(N);
+    if (SqrtOp.getNode())
+      return SqrtOp;
   }
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chandlerc wrote:
> You can make SqrtOp a condition variable now, I fixed SDValue to support this:
> 
>   if (SDValue SqrtOp = BuildRSQRTE(N))
>     return SqrtOp;
Nice! There's a lot more where that came from...

http://reviews.llvm.org/D5425