[Power9]Legalize and emit code for quad-precision convert from double-precision

Legalize and emit code for quad-precision floating point operation xscvdpqp
and add option to guard the quad precision operation support.

Differential Revision: https://reviews.llvm.org/D44746

llvm-svn: 328558

2 files changed, 13 insertions, 5 deletions

diff --git a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
index 78e498c4630..986e617801e 100644
--- a/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
+++ b/llvm/lib/Target/PowerPC/PPCISelLowering.cpp
@@ -111,6 +111,9 @@ cl::desc("disable unaligned load/store generation on PPC"), cl::Hidden);
 static cl::opt<bool> DisableSCO("disable-ppc-sco",
 cl::desc("disable sibling call optimization on ppc"), cl::Hidden);
 
+static cl::opt<bool> EnableQuadPrecision("enable-ppc-quad-precision",
+cl::desc("enable quad precision float support on ppc"), cl::Hidden);
+
 STATISTIC(NumTailCalls, "Number of tail calls");
 STATISTIC(NumSiblingCalls, "Number of sibling calls");
 
@@ -787,11 +790,15 @@ PPCTargetLowering::PPCTargetLowering(const PPCTargetMachine &TM,
       setOperationAction(ISD::SRL, MVT::v1i128, Legal);
       setOperationAction(ISD::SRA, MVT::v1i128, Expand);
 
-      addRegisterClass(MVT::f128, &PPC::VRRCRegClass);
-      setOperationAction(ISD::FADD, MVT::f128, Legal);
-      setOperationAction(ISD::FSUB, MVT::f128, Legal);
-      setOperationAction(ISD::FDIV, MVT::f128, Legal);
-      setOperationAction(ISD::FMUL, MVT::f128, Legal);
+      if (EnableQuadPrecision) {
+        addRegisterClass(MVT::f128, &PPC::VRRCRegClass);
+        setOperationAction(ISD::FADD, MVT::f128, Legal);
+        setOperationAction(ISD::FSUB, MVT::f128, Legal);
+        setOperationAction(ISD::FDIV, MVT::f128, Legal);
+        setOperationAction(ISD::FMUL, MVT::f128, Legal);
+        setOperationAction(ISD::FP_EXTEND, MVT::f128, Legal);
+        setLoadExtAction(ISD::EXTLOAD, MVT::f128, MVT::f64, Expand);
+      }
 
     }
 
diff --git a/llvm/lib/Target/PowerPC/PPCInstrVSX.td b/llvm/lib/Target/PowerPC/PPCInstrVSX.td
index b861618a8c3..d21f6b8d07b 100644
--- a/llvm/lib/Target/PowerPC/PPCInstrVSX.td
+++ b/llvm/lib/Target/PowerPC/PPCInstrVSX.td
@@ -2470,6 +2470,7 @@ let AddedComplexity = 400, Predicates = [HasP9Vector] in {
 
   // Convert DP -> QP
   def XSCVDPQP  : X_VT5_XO5_VB5_TyVB<63, 22, 836, "xscvdpqp", vfrc, []>;
+  def : Pat<(f128 (fpextend f64:$src)), (f128 (XSCVDPQP $src))>;
 
   // Round & Convert QP -> DP (dword[1] is set to zero)
   def XSCVQPDP  : X_VT5_XO5_VB5   <63, 20, 836, "xscvqpdp" , []>;