From f36febf578af586eda2eaab1a0b212ec641a7c94 Mon Sep 17 00:00:00 2001
From: Roman Divacky <rdivacky@freebsd.org>
Date: Thu, 27 Feb 2014 19:26:29 +0000
Subject: [PATCH] Lower FNEG just like FABS to fneg[ds] and fmov[ds], thus
 avoiding expensive libcall. Also, Qp_neg is not implemented on at least
 FreeBSD. This is also what gcc is doing.

llvm-svn: 202422
---
 lib/Target/Sparc/SparcISelLowering.cpp | 25 ++++++++-----------------
 test/CodeGen/SPARC/fp128.ll            | 11 +++++++++++
 2 files changed, 19 insertions(+), 17 deletions(-)

diff --git a/lib/Target/Sparc/SparcISelLowering.cpp b/lib/Target/Sparc/SparcISelLowering.cpp
index 2ac5b7e8c22..632cc2b8b7f 100644
--- a/lib/Target/Sparc/SparcISelLowering.cpp
+++ b/lib/Target/Sparc/SparcISelLowering.cpp
@@ -2648,24 +2648,16 @@ static SDValue LowerF128Store(SDValue Op, SelectionDAG &DAG) {
                      &OutChains[0], 2);
 }
 
-static SDValue LowerFNEG(SDValue Op, SelectionDAG &DAG,
-                         const SparcTargetLowering &TLI,
-                         bool is64Bit) {
-  if (Op.getValueType() == MVT::f64)
-    return LowerF64Op(Op, DAG, ISD::FNEG);
-  if (Op.getValueType() == MVT::f128)
-    return TLI.LowerF128Op(Op, DAG, ((is64Bit) ? "_Qp_neg" : "_Q_neg"), 1);
-  return Op;
-}
+static SDValue LowerFNEGorFABS(SDValue Op, SelectionDAG &DAG, bool isV9) {
+  assert((Op.getOpcode() == ISD::FNEG || Op.getOpcode() == ISD::FABS) && "invalid");
 
-static SDValue LowerFABS(SDValue Op, SelectionDAG &DAG, bool isV9) {
   if (Op.getValueType() == MVT::f64)
-    return LowerF64Op(Op, DAG, ISD::FABS);
+    return LowerF64Op(Op, DAG, Op.getOpcode());
   if (Op.getValueType() != MVT::f128)
     return Op;
 
-  // Lower fabs on f128 to fabs on f64
-  // fabs f128 => fabs f64:sub_even64, fmov f64:sub_odd64
+  // Lower fabs/fneg on f128 to fabs/fneg on f64
+  // fabs/fneg f128 => fabs/fneg f64:sub_even64, fmov f64:sub_odd64
 
   SDLoc dl(Op);
   SDValue SrcReg128 = Op.getOperand(0);
@@ -2676,7 +2668,7 @@ static SDValue LowerFABS(SDValue Op, SelectionDAG &DAG, bool isV9) {
   if (isV9)
     Hi64 = DAG.getNode(Op.getOpcode(), dl, MVT::f64, Hi64);
   else
-    Hi64 = LowerF64Op(Hi64, DAG, ISD::FABS);
+    Hi64 = LowerF64Op(Hi64, DAG, Op.getOpcode());
 
   SDValue DstReg128 = SDValue(DAG.getMachineNode(TargetOpcode::IMPLICIT_DEF,
                                                  dl, MVT::f128), 0);
@@ -2797,7 +2789,6 @@ SDValue SparcTargetLowering::
 LowerOperation(SDValue Op, SelectionDAG &DAG) const {
 
   bool hasHardQuad = Subtarget->hasHardQuad();
-  bool is64Bit     = Subtarget->is64Bit();
   bool isV9        = Subtarget->isV9();
 
   switch (Op.getOpcode()) {
@@ -2840,8 +2831,8 @@ LowerOperation(SDValue Op, SelectionDAG &DAG) const {
                                        getLibcallName(RTLIB::DIV_F128), 2);
   case ISD::FSQRT:              return LowerF128Op(Op, DAG,
                                        getLibcallName(RTLIB::SQRT_F128),1);
-  case ISD::FNEG:               return LowerFNEG(Op, DAG, *this, is64Bit);
-  case ISD::FABS:               return LowerFABS(Op, DAG, isV9);
+  case ISD::FABS:
+  case ISD::FNEG:               return LowerFNEGorFABS(Op, DAG, isV9);
   case ISD::FP_EXTEND:          return LowerF128_FPEXTEND(Op, DAG, *this);
   case ISD::FP_ROUND:           return LowerF128_FPROUND(Op, DAG, *this);
   case ISD::ADDC:
diff --git a/test/CodeGen/SPARC/fp128.ll b/test/CodeGen/SPARC/fp128.ll
index 37e759ff9eb..abd89bf264e 100644
--- a/test/CodeGen/SPARC/fp128.ll
+++ b/test/CodeGen/SPARC/fp128.ll
@@ -232,3 +232,14 @@ entry:
   store  i32 %3, i32* %4, align 8
   ret void
 }
+
+; SOFT-LABEL:     f128_neg
+; SOFT:           fnegs
+
+define void @f128_neg(fp128* noalias sret %scalar.result, fp128* byval %a) {
+entry:
+  %0 = load fp128* %a, align 8
+  %1 = fsub fp128 0xL00000000000000008000000000000000, %0
+  store fp128 %1, fp128* %scalar.result, align 8
+  ret void
+}