Add 'Indirect' LocInfo class and use to pass __m128 on win64. Also minore fixes here and there (mostly __m64).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@77964 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86CallingConv.td b/lib/Target/X86/X86CallingConv.td
index 5239dd1..d77f039 100644
--- a/lib/Target/X86/X86CallingConv.td
+++ b/lib/Target/X86/X86CallingConv.td
@@ -89,7 +89,7 @@
 // X86-Win64 C return-value convention.
 def RetCC_X86_Win64_C : CallingConv<[
   // The X86-Win64 calling convention always returns __m64 values in RAX.
-  CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToReg<[RAX]>>,
+  CCIfType<[v8i8, v4i16, v2i32, v1i64], CCBitConvertToType<i64>>,
 
   // And FP in XMM0 only.
   CCIfType<[f32], CCAssignToReg<[XMM0]>>,
@@ -184,6 +184,13 @@
   // The 'nest' parameter, if any, is passed in R10.
   CCIfNest<CCAssignToReg<[R10]>>,
 
+  // 128 bit vectors are passed by pointer
+  CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCPassIndirect<i64>>,
+
+  // The first 4 MMX vector arguments are passed in GPRs.
+  CCIfType<[v8i8, v4i16, v2i32, v1i64, v2f32],
+           CCBitConvertToType<i64>>,
+
   // The first 4 integer arguments are passed in integer registers.
   CCIfType<[i32], CCAssignToRegWithShadow<[ECX , EDX , R8D , R9D ],
                                           [XMM0, XMM1, XMM2, XMM3]>>,
@@ -195,11 +202,6 @@
            CCAssignToRegWithShadow<[XMM0, XMM1, XMM2, XMM3],
                                    [RCX , RDX , R8  , R9  ]>>,
 
-  // The first 4 MMX vector arguments are passed in GPRs.
-  CCIfType<[v8i8, v4i16, v2i32, v1i64, v2f32],
-           CCAssignToRegWithShadow<[RCX , RDX , R8  , R9  ],
-                                   [XMM0, XMM1, XMM2, XMM3]>>,
-
   // Integer/FP values get stored in stack slots that are 8 bytes in size and
   // 8-byte aligned if there are no more registers to hold them.
   CCIfType<[i32, i64, f32, f64], CCAssignToStack<8, 8>>,
@@ -208,9 +210,6 @@
   // subtarget.
   CCIfType<[f80], CCAssignToStack<0, 0>>,
 
-  // Vectors get 16-byte stack slots that are 16-byte aligned.
-  CCIfType<[v16i8, v8i16, v4i32, v2i64, v4f32, v2f64], CCAssignToStack<16, 16>>,
-
   // __m64 vectors get 8-byte stack slots that are 8-byte aligned.
   CCIfType<[v8i8, v4i16, v2i32, v1i64], CCAssignToStack<8, 8>>
 ]>;
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index ef387bb..a46ec1c 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1408,6 +1408,7 @@
 
   SmallVector<SDValue, 8> ArgValues;
   unsigned LastVal = ~0U;
+  SDValue ArgValue;
   for (unsigned i = 0, e = ArgLocs.size(); i != e; ++i) {
     CCValAssign &VA = ArgLocs[i];
     // TODO: If an arg is passed in two places (e.g. reg and stack), skip later
@@ -1435,7 +1436,7 @@
         llvm_unreachable("Unknown argument type!");
 
       unsigned Reg = MF.addLiveIn(VA.getLocReg(), RC);
-      SDValue ArgValue = DAG.getCopyFromReg(Root, dl, Reg, RegVT);
+      ArgValue = DAG.getCopyFromReg(Root, dl, Reg, RegVT);
 
       // If this is an 8 or 16-bit value, it is really passed promoted to 32
       // bits.  Insert an assert[sz]ext to capture this, then truncate to the
@@ -1450,8 +1451,7 @@
         ArgValue = DAG.getNode(ISD::BIT_CONVERT, dl, RegVT, ArgValue,
                                DAG.getValueType(VA.getValVT()));
 
-      if (VA.getLocInfo() != CCValAssign::Full &&
-          VA.getLocInfo() != CCValAssign::BCvt) {
+      if (VA.isExtInLoc()) {
         // Handle MMX values passed in XMM regs.
         if (RegVT.isVector()) {
           ArgValue = DAG.getNode(ISD::EXTRACT_VECTOR_ELT, dl, MVT::i64,
@@ -1460,12 +1460,16 @@
         } else
           ArgValue = DAG.getNode(ISD::TRUNCATE, dl, VA.getValVT(), ArgValue);
       }
-
-      ArgValues.push_back(ArgValue);
     } else {
       assert(VA.isMemLoc());
-      ArgValues.push_back(LowerMemArgument(Op, DAG, VA, MFI, CC, Root, i));
+      ArgValue = LowerMemArgument(Op, DAG, VA, MFI, CC, Root, i);
     }
+
+    // If value is passed via pointer - do a load.
+    if (VA.getLocInfo() == CCValAssign::Indirect)
+      ArgValue = DAG.getLoad(VA.getValVT(), dl, Root, ArgValue, NULL, 0);
+
+    ArgValues.push_back(ArgValue);
   }
 
   // The x86-64 ABI for returning structs by value requires that we copy
@@ -1747,6 +1751,15 @@
     case CCValAssign::BCvt:
       Arg = DAG.getNode(ISD::BIT_CONVERT, dl, RegVT, Arg);
       break;
+    case CCValAssign::Indirect: {
+      // Store the argument.
+      SDValue SpillSlot = DAG.CreateStackTemporary(VA.getValVT());
+      int FI = cast<FrameIndexSDNode>(SpillSlot)->getIndex();
+      Chain = DAG.getStore(Chain, dl, Arg, SpillSlot,
+                           PseudoSourceValue::getFixedStack(FI), 0);
+      Arg = SpillSlot;
+      break;
+    }
     }
 
     if (VA.isRegLoc()) {