From: Chris Lattner <sabre@nondot.org>
Date: Sat, 29 Dec 2007 06:55:23 +0000 (+0000)
Subject: don't fold fp_round(fp_extend(load)) -> fp_round(extload)
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5938bef2d259ca7648481ec3fb4cefbdff22458d;p=oota-llvm.git

don't fold fp_round(fp_extend(load)) -> fp_round(extload)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45400 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 242fffd1802..0ee45575633 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -3672,6 +3672,10 @@ SDOperand DAGCombiner::visitFP_EXTEND(SDNode *N) {
   ConstantFPSDNode *N0CFP = dyn_cast<ConstantFPSDNode>(N0);
   MVT::ValueType VT = N->getValueType(0);
   
+  // If this is fp_round(fpextend), don't fold it, allow ourselves to be folded.
+  if (N->hasOneUse() && (*N->use_begin())->getOpcode() == ISD::FP_ROUND)
+    return SDOperand();
+  
   // fold (fp_extend c1fp) -> c1fp
   if (N0CFP && VT != MVT::ppcf128)
     return DAG.getNode(ISD::FP_EXTEND, VT, N0);