support IDEF, fnegabs (thanks sampo)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21023 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/IA64/IA64ISelPattern.cpp b/lib/Target/IA64/IA64ISelPattern.cpp
index 7b976fc..599f289 100644
--- a/lib/Target/IA64/IA64ISelPattern.cpp
+++ b/lib/Target/IA64/IA64ISelPattern.cpp
@@ -609,6 +609,11 @@
 
   return Result;
   }
+
+  case ISD::UNDEF: {
+    BuildMI(BB, IA64::IDEF, 0, Result);
+    return Result;
+  }
     
   case ISD::GlobalAddress: {
     GlobalValue *GV = cast<GlobalAddressSDNode>(N)->getGlobal();
@@ -799,9 +804,16 @@
   }
  
   case ISD::FNEG: {
-    Tmp1 = SelectExpr(N.getOperand(0));
     assert(DestType == MVT::f64 && "trying to fneg something other than f64?");
-    BuildMI(BB, IA64::FNEG, 1, Result).addReg(Tmp1);
+
+    if (ISD::FABS == N.getOperand(0).getOpcode()) { // && hasOneUse()? 
+      Tmp1 = SelectExpr(N.getOperand(0).getOperand(0));
+      BuildMI(BB, IA64::FNEGABS, 1, Result).addReg(Tmp1); // fold in abs
+    } else {
+      Tmp1 = SelectExpr(N.getOperand(0));
+      BuildMI(BB, IA64::FNEG, 1, Result).addReg(Tmp1); // plain old fneg
+    }
+
     return Result;
   }