From 4961709688be9e21985e413e296e84e391ae92ac Mon Sep 17 00:00:00 2001
From: Akira Hatanaka <ahatanaka@mips.com>
Date: Mon, 14 Nov 2011 19:02:54 +0000
Subject: [PATCH] AnalyzeCallOperands function for N32/64.

N32/64 places all variable arguments in integer registers (or on stack),
regardless of their types, but follows calling convention of non-vaarg function
when it handles fixed arguments.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144553 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Target/Mips/MipsCallingConv.td   | 19 +++++++++++++++++++
 lib/Target/Mips/MipsISelLowering.cpp | 26 ++++++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/lib/Target/Mips/MipsCallingConv.td b/lib/Target/Mips/MipsCallingConv.td
index b8a863b2a48..3d973ceeb0a 100644
--- a/lib/Target/Mips/MipsCallingConv.td
+++ b/lib/Target/Mips/MipsCallingConv.td
@@ -64,6 +64,25 @@ def CC_MipsN : CallingConv<[
   CCIfType<[f32], CCAssignToStack<4, 8>>
 ]>;
 
+// N32/64 variable arguments.
+// All arguments are passed in integer registers.
+def CC_MipsN_VarArg : CallingConv<[
+   // Handles byval parameters.
+  CCIfByVal<CCCustom<"CC_Mips64Byval">>,
+ 
+  // Promote i8/i16/i32 arguments to i64.
+  CCIfType<[i8, i16, i32], CCPromoteToType<i64>>,
+
+  CCIfType<[i64, f64], CCAssignToReg<[A0_64, A1_64, A2_64, A3_64,
+                                      T0_64, T1_64, T2_64, T3_64]>>,
+
+  CCIfType<[f32], CCAssignToReg<[A0, A1, A2, A3, T0, T1, T2, T3]>>,
+
+  // All stack parameter slots become 64-bit doublewords and are 8-byte aligned.
+  CCIfType<[i64, f64], CCAssignToStack<8, 8>>,
+  CCIfType<[f32], CCAssignToStack<4, 8>>
+]>;
+
 def RetCC_MipsN : CallingConv<[
   // FIXME: Handle complex and float double return values.
 
diff --git a/lib/Target/Mips/MipsISelLowering.cpp b/lib/Target/Mips/MipsISelLowering.cpp
index 33cb26135bc..c01ddf0b788 100644
--- a/lib/Target/Mips/MipsISelLowering.cpp
+++ b/lib/Target/Mips/MipsISelLowering.cpp
@@ -1918,6 +1918,30 @@ static bool CC_Mips64Byval(unsigned ValNo, MVT ValVT, MVT LocVT,
 
 #include "MipsGenCallingConv.inc"
 
+static void
+AnalyzeMips64CallOperands(CCState CCInfo,
+                          const SmallVectorImpl<ISD::OutputArg> &Outs) {
+  unsigned NumOps = Outs.size();
+  for (unsigned i = 0; i != NumOps; ++i) {
+    MVT ArgVT = Outs[i].VT;
+    ISD::ArgFlagsTy ArgFlags = Outs[i].Flags;
+    bool R;
+
+    if (Outs[i].IsFixed)
+      R = CC_MipsN(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, CCInfo);
+    else
+      R = CC_MipsN_VarArg(i, ArgVT, ArgVT, CCValAssign::Full, ArgFlags, CCInfo);
+      
+#ifndef NDEBUG
+    if (R) {
+      dbgs() << "Call operand #" << i << " has unhandled type "
+             << EVT(ArgVT).getEVTString();
+#endif
+      llvm_unreachable(0);
+    }
+  }
+}
+
 //===----------------------------------------------------------------------===//
 //                  Call Calling Convention Implementation
 //===----------------------------------------------------------------------===//
@@ -2138,6 +2162,8 @@ MipsTargetLowering::LowerCall(SDValue InChain, SDValue Callee,
 
   if (IsO32)
     CCInfo.AnalyzeCallOperands(Outs, CC_MipsO32);
+  else if (HasMips64)
+    AnalyzeMips64CallOperands(CCInfo, Outs);
   else
     CCInfo.AnalyzeCallOperands(Outs, CC_Mips);