propagate struct size and alignment of byval arguments to the DAG

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40986 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 25 insertions, 3 deletions

diff --git a/lib/CodeGen/SelectionDAG/CallingConvLower.cpp b/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
index defbe34..bcd132f 100644
--- a/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
+++ b/lib/CodeGen/SelectionDAG/CallingConvLower.cpp
@@ -28,6 +28,17 @@ CCState::CCState(unsigned CC, bool isVarArg, const TargetMachine &tm,
   UsedRegs.resize(MRI.getNumRegs());
 }
 
+void CCState::HandleStruct(unsigned ValNo, MVT::ValueType ValVT,
+                           MVT::ValueType LocVT, CCValAssign::LocInfo LocInfo,
+                           unsigned ArgFlags) {
+  unsigned Align  = 1 << ((ArgFlags & ISD::ParamFlags::ByValAlign) >>
+                          ISD::ParamFlags::ByValAlignOffs);
+  unsigned Size   = (ArgFlags & ISD::ParamFlags::ByValSize) >>
+      ISD::ParamFlags::ByValSizeOffs;
+  unsigned Offset = AllocateStack(Size, Align);
+
+  addLoc(CCValAssign::getMem(ValNo, ValVT, Offset, LocVT, LocInfo));
+}
 
 /// MarkAllocated - Mark a register and all of its aliases as allocated.
 void CCState::MarkAllocated(unsigned Reg) {
@@ -99,4 +110,3 @@ void CCState::AnalyzeCallResult(SDNode *TheCall, CCAssignFn Fn) {
     }
   }
 }
-
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index afb681f..df40972 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -3836,8 +3836,15 @@ TargetLowering::LowerArguments(Function &F, SelectionDAG &DAG) {
       Flags |= ISD::ParamFlags::InReg;
     if (Attrs && Attrs->paramHasAttr(j, ParamAttr::StructRet))
       Flags |= ISD::ParamFlags::StructReturn;
-    if (Attrs && Attrs->paramHasAttr(j, ParamAttr::ByVal))
+    if (Attrs && Attrs->paramHasAttr(j, ParamAttr::ByVal)) {
       Flags |= ISD::ParamFlags::ByVal;
+      const PointerType *Ty = cast<PointerType>(I->getType());
+      const StructType *STy = cast<StructType>(Ty->getElementType());
+      unsigned StructAlign = Log2_32(getTargetData()->getABITypeAlignment(STy));
+      unsigned StructSize  = getTargetData()->getTypeSize(STy);
+      Flags |= (StructAlign << ISD::ParamFlags::ByValAlignOffs);
+      Flags |= (StructSize  << ISD::ParamFlags::ByValSizeOffs);
+    }
     if (Attrs && Attrs->paramHasAttr(j, ParamAttr::Nest))
       Flags |= ISD::ParamFlags::Nest;
     Flags |= (OriginalAlignment << ISD::ParamFlags::OrigAlignmentOffs);
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 3af3934..184e355 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -1260,7 +1260,12 @@ X86TargetLowering::LowerX86_64CCCArguments(SDOperand Op, SelectionDAG &DAG) {
       int FI = MFI->CreateFixedObject(MVT::getSizeInBits(VA.getValVT())/8,
                                       VA.getLocMemOffset());
       SDOperand FIN = DAG.getFrameIndex(FI, getPointerTy());
-      ArgValues.push_back(DAG.getLoad(VA.getValVT(), Root, FIN, NULL, 0));
+
+      unsigned Flags =  cast<ConstantSDNode>(Op.getOperand(3 + i))->getValue();
+      if (Flags & ISD::ParamFlags::ByVal)
+        ArgValues.push_back(FIN);
+      else
+        ArgValues.push_back(DAG.getLoad(VA.getValVT(), Root, FIN, NULL, 0));
     }
   }