Do away with addLegalFPImmediate. Add a target hook isFPImmLegal which returns true if the fp immediate can be natively codegened by target.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85281 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index ab8790a..48d1cdc 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -72,9 +72,6 @@
     if (!Subtarget->isFP64bit())
       addRegisterClass(MVT::f64, Mips::AFGR64RegisterClass);
 
-  // Legal fp constants
-  addLegalFPImmediate(APFloat(+0.0f));
-
   // Load extented operations for i1 types must be promoted 
   setLoadExtAction(ISD::EXTLOAD,  MVT::i1,  Promote);
   setLoadExtAction(ISD::ZEXTLOAD, MVT::i1,  Promote);
@@ -1224,3 +1221,7 @@
   // The Mips target isn't yet aware of offsets.
   return false;
 }
+
+bool MipsTargetLowering::isFPImmLegal(const APFloat &Imm) const {
+  return Imm.isZero();
+}