Missed pieces for ARM HardFP ABI.
Patch by Sandeep Patel!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78225 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMISelLowering.cpp b/lib/Target/ARM/ARMISelLowering.cpp
index af18c27..61a08db 100644
--- a/lib/Target/ARM/ARMISelLowering.cpp
+++ b/lib/Target/ARM/ARMISelLowering.cpp
@@ -662,27 +662,28 @@
 /// CCAssignFnForNode - Selects the correct CCAssignFn for a the
 /// given CallingConvention value.
 CCAssignFn *ARMTargetLowering::CCAssignFnForNode(unsigned CC,
-                                                 bool Return) const {
+                                                 bool Return,
+                                                 bool isVarArg) const {
   switch (CC) {
   default:
-   llvm_unreachable("Unsupported calling convention");
+    llvm_unreachable("Unsupported calling convention");
   case CallingConv::C:
   case CallingConv::Fast:
-   // Use target triple & subtarget features to do actual dispatch.
-   if (Subtarget->isAAPCS_ABI()) {
-     if (Subtarget->hasVFP2() &&
-         FloatABIType == FloatABI::Hard)
-       return (Return ? RetCC_ARM_AAPCS_VFP: CC_ARM_AAPCS_VFP);
-     else
-       return (Return ? RetCC_ARM_AAPCS: CC_ARM_AAPCS);
-   } else
-     return (Return ? RetCC_ARM_APCS: CC_ARM_APCS);
+    // Use target triple & subtarget features to do actual dispatch.
+    if (Subtarget->isAAPCS_ABI()) {
+      if (Subtarget->hasVFP2() &&
+          FloatABIType == FloatABI::Hard && !isVarArg)
+        return (Return ? RetCC_ARM_AAPCS_VFP: CC_ARM_AAPCS_VFP);
+      else
+        return (Return ? RetCC_ARM_AAPCS: CC_ARM_AAPCS);
+    } else
+        return (Return ? RetCC_ARM_APCS: CC_ARM_APCS);
   case CallingConv::ARM_AAPCS_VFP:
-   return (Return ? RetCC_ARM_AAPCS_VFP: CC_ARM_AAPCS_VFP);
+    return (Return ? RetCC_ARM_AAPCS_VFP: CC_ARM_AAPCS_VFP);
   case CallingConv::ARM_AAPCS:
-   return (Return ? RetCC_ARM_AAPCS: CC_ARM_AAPCS);
+    return (Return ? RetCC_ARM_AAPCS: CC_ARM_AAPCS);
   case CallingConv::ARM_APCS:
-   return (Return ? RetCC_ARM_APCS: CC_ARM_APCS);
+    return (Return ? RetCC_ARM_APCS: CC_ARM_APCS);
   }
 }
 
@@ -700,7 +701,8 @@
   CCState CCInfo(CallConv, isVarArg, getTargetMachine(),
                  RVLocs, *DAG.getContext());
   CCInfo.AnalyzeCallResult(Ins,
-                           CCAssignFnForNode(CallConv, /* Return*/ true));
+                           CCAssignFnForNode(CallConv, /* Return*/ true,
+                                             isVarArg));
 
   // Copy all of the result registers out of their specified physreg.
   for (unsigned i = 0; i != RVLocs.size(); ++i) {
@@ -832,7 +834,8 @@
   CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs,
                  *DAG.getContext());
   CCInfo.AnalyzeCallOperands(Outs,
-                             CCAssignFnForNode(CallConv, /* Return*/ false));
+                             CCAssignFnForNode(CallConv, /* Return*/ false,
+                                               isVarArg));
 
   // Get a count of how many bytes are to be pushed on the stack.
   unsigned NumBytes = CCInfo.getNextStackOffset();
@@ -873,7 +876,7 @@
       break;
     }
 
-    // f64 and v2f64 are passed in i32 pairs and must be split into pieces
+    // f64 and v2f64 might be passed in i32 pairs and must be split into pieces
     if (VA.needsCustom()) {
       if (VA.getLocVT() == MVT::v2f64) {
         SDValue Op0 = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::f64, Arg,
@@ -1034,7 +1037,8 @@
                  *DAG.getContext());
 
   // Analyze outgoing return values.
-  CCInfo.AnalyzeReturn(Outs, CCAssignFnForNode(CallConv, /* Return */ true));
+  CCInfo.AnalyzeReturn(Outs, CCAssignFnForNode(CallConv, /* Return */ true,
+                                               isVarArg));
 
   // If this is the first return lowered for this function, add
   // the regs to the liveout set for the function.
@@ -1422,7 +1426,8 @@
   CCState CCInfo(CallConv, isVarArg, getTargetMachine(), ArgLocs,
                  *DAG.getContext());
   CCInfo.AnalyzeFormalArguments(Ins,
-                                CCAssignFnForNode(CallConv, /* Return*/ false));
+                                CCAssignFnForNode(CallConv, /* Return*/ false,
+                                                  isVarArg));
 
   SmallVector<SDValue, 16> ArgValues;
 
@@ -1455,18 +1460,23 @@
 
       } else {
         TargetRegisterClass *RC;
-        if (FloatABIType == FloatABI::Hard && RegVT == MVT::f32)
+        bool IsHardFloatCC = (CallConv == CallingConv::ARM_AAPCS_VFP);
+
+        if (IsHardFloatCC && RegVT == MVT::f32)
           RC = ARM::SPRRegisterClass;
-        else if (FloatABIType == FloatABI::Hard && RegVT == MVT::f64)
+        else if (IsHardFloatCC && RegVT == MVT::f64)
           RC = ARM::DPRRegisterClass;
+        else if (IsHardFloatCC && RegVT == MVT::v2f64)
+          RC = ARM::QPRRegisterClass;
         else if (AFI->isThumb1OnlyFunction())
           RC = ARM::tGPRRegisterClass;
         else
           RC = ARM::GPRRegisterClass;
 
         assert((RegVT == MVT::i32 || RegVT == MVT::f32 ||
-                (FloatABIType == FloatABI::Hard && RegVT == MVT::f64)) &&
-               "RegVT not supported by formal arguments Lowering");
+                (IsHardFloatCC &&
+                 ((RegVT == MVT::f64) || (RegVT == MVT::v2f64)))) &&
+               "RegVT not supported by FORMAL_ARGUMENTS Lowering");
 
         // Transform the arguments in physical registers into virtual ones.
         unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);