[PATCH] D17221: Don't combine fp_round (fp_round x) if f80 to f16 is generated

[Ahmed Bougacha via llvm-commits]

ab added inline comments.

================
Comment at: lib/CodeGen/SelectionDAG/DAGCombiner.cpp:9030
@@ +9029,3 @@
+    // x86.
+    if (N0.getOperand(0).getValueType() == MVT::f80 && VT == MVT::f16)
+      return SDValue();
----------------
How do we know that the round is value-preserving?


http://reviews.llvm.org/D17221