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/SystemZ/SystemZISelLowering.cpp b/lib/Target/SystemZ/SystemZISelLowering.cpp
index 07e0d83..eb4d250 100644
--- a/lib/Target/SystemZ/SystemZISelLowering.cpp
+++ b/lib/Target/SystemZ/SystemZISelLowering.cpp
@@ -53,11 +53,6 @@
   if (!UseSoftFloat) {
     addRegisterClass(MVT::f32, SystemZ::FP32RegisterClass);
     addRegisterClass(MVT::f64, SystemZ::FP64RegisterClass);
-
-    addLegalFPImmediate(APFloat(+0.0));  // lzer
-    addLegalFPImmediate(APFloat(+0.0f)); // lzdr
-    addLegalFPImmediate(APFloat(-0.0));  // lzer + lner
-    addLegalFPImmediate(APFloat(-0.0f)); // lzdr + lndr
   }
 
   // Compute derived properties from the register classes
@@ -169,6 +164,17 @@
   }
 }
 
+bool SystemZTargetLowering::isFPImmLegal(const APFloat &Imm) const {
+  if (UseSoftFloat)
+    return false;
+
+  // +0.0  lzer
+  // +0.0f lzdr
+  // -0.0  lzer + lner
+  // -0.0f lzdr + lndr
+  return Imm.isZero() || Imm.isNegZero();
+}
+
 //===----------------------------------------------------------------------===//
 //                       SystemZ Inline Assembly Support
 //===----------------------------------------------------------------------===//