[GlobalISel] Rewrite CallLowering::lowerReturn to accept multiple VRegs per Value

This is logical continuation of https://reviews.llvm.org/D46018 (r332449)

Differential Revision: https://reviews.llvm.org/D49660

llvm-svn: 338685

2 files changed, 19 insertions, 9 deletions

diff --git a/llvm/lib/Target/Mips/MipsCallLowering.cpp b/llvm/lib/Target/Mips/MipsCallLowering.cpp
index a705ebb6b19..47b9617af90 100644
--- a/llvm/lib/Target/Mips/MipsCallLowering.cpp
+++ b/llvm/lib/Target/Mips/MipsCallLowering.cpp
@@ -16,6 +16,7 @@
 #include "MipsCallLowering.h"
 #include "MipsCCState.h"
 #include "MipsTargetMachine.h"
+#include "llvm/CodeGen/Analysis.h"
 #include "llvm/CodeGen/GlobalISel/MachineIRBuilder.h"
 
 using namespace llvm;
@@ -192,25 +193,34 @@ static bool isSupportedType(Type *T) {
 }
 
 bool MipsCallLowering::lowerReturn(MachineIRBuilder &MIRBuilder,
-                                   const Value *Val, unsigned VReg) const {
+                                      const Value *Val,
+                                      ArrayRef<unsigned> VRegs) const {
 
   MachineInstrBuilder Ret = MIRBuilder.buildInstrNoInsert(Mips::RetRA);
 
-  if (Val != nullptr) {
-    if (!isSupportedType(Val->getType()))
-      return false;
+  if (Val != nullptr && !isSupportedType(Val->getType()))
+    return false;
 
+  if (!VRegs.empty()) {
     MachineFunction &MF = MIRBuilder.getMF();
     const Function &F = MF.getFunction();
     const DataLayout &DL = MF.getDataLayout();
     const MipsTargetLowering &TLI = *getTLI<MipsTargetLowering>();
+    LLVMContext &Ctx = Val->getType()->getContext();
+
+    SmallVector<EVT, 4> SplitEVTs;
+    ComputeValueVTs(TLI, DL, Val->getType(), SplitEVTs);
+    assert(VRegs.size() == SplitEVTs.size() &&
+           "For each split Type there should be exactly one VReg.");
 
     SmallVector<ArgInfo, 8> RetInfos;
     SmallVector<unsigned, 8> OrigArgIndices;
 
-    ArgInfo ArgRetInfo(VReg, Val->getType());
-    setArgFlags(ArgRetInfo, AttributeList::ReturnIndex, DL, F);
-    splitToValueTypes(ArgRetInfo, 0, RetInfos, OrigArgIndices);
+    for (unsigned i = 0; i < SplitEVTs.size(); ++i) {
+      ArgInfo CurArgInfo = ArgInfo{VRegs[i], SplitEVTs[i].getTypeForEVT(Ctx)};
+      setArgFlags(CurArgInfo, AttributeList::ReturnIndex, DL, F);
+      splitToValueTypes(CurArgInfo, 0, RetInfos, OrigArgIndices);
+    }
 
     SmallVector<ISD::OutputArg, 8> Outs;
     subTargetRegTypeForCallingConv(
diff --git a/llvm/lib/Target/Mips/MipsCallLowering.h b/llvm/lib/Target/Mips/MipsCallLowering.h
index e23c10cec56..5f696b0e056 100644
--- a/llvm/lib/Target/Mips/MipsCallLowering.h
+++ b/llvm/lib/Target/Mips/MipsCallLowering.h
@@ -50,8 +50,8 @@ public:
 
   MipsCallLowering(const MipsTargetLowering &TLI);
 
-  bool lowerReturn(MachineIRBuilder &MIRBuiler, const Value *Val,
-                   unsigned VReg) const override;
+  bool lowerReturn(MachineIRBuilder &MIRBuilder, const Value *Val,
+                   ArrayRef<unsigned> VRegs) const;
 
   bool lowerFormalArguments(MachineIRBuilder &MIRBuilder, const Function &F,
                             ArrayRef<unsigned> VRegs) const override;