From: Chris Lattner <sabre@nondot.org>
Date: Sun, 27 Jan 2008 06:19:31 +0000 (+0000)
Subject: Use fldz and fld1 for long double constants instead of a constant pool load.
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=71d07a0dacd113b656a256c17b66b583e1ab76ec;p=oota-llvm.git

Use fldz and fld1 for long double constants instead of a constant pool load.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46411 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index f07793b4d93..90408c8da33 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -455,7 +455,20 @@ X86TargetLowering::X86TargetLowering(TargetMachine &TM)
   addRegisterClass(MVT::f80, X86::RFP80RegisterClass);
   setOperationAction(ISD::UNDEF,     MVT::f80, Expand);
   setOperationAction(ISD::FCOPYSIGN, MVT::f80, Expand);
-  setOperationAction(ISD::ConstantFP, MVT::f80, Expand);
+  {
+    setOperationAction(ISD::ConstantFP, MVT::f80, Expand);
+    APFloat TmpFlt(+0.0);
+    TmpFlt.convert(APFloat::x87DoubleExtended, APFloat::rmNearestTiesToEven);
+    addLegalFPImmediate(TmpFlt);  // FLD0
+    TmpFlt.changeSign();
+    addLegalFPImmediate(TmpFlt);  // FLD0/FCHS
+    APFloat TmpFlt2(+1.0);
+    TmpFlt2.convert(APFloat::x87DoubleExtended, APFloat::rmNearestTiesToEven);
+    addLegalFPImmediate(TmpFlt2);  // FLD1
+    TmpFlt2.changeSign();
+    addLegalFPImmediate(TmpFlt2);  // FLD1/FCHS
+  }
+    
   if (!UnsafeFPMath) {
     setOperationAction(ISD::FSIN           , MVT::f80  , Expand);
     setOperationAction(ISD::FCOS           , MVT::f80  , Expand);