Add support for byval args. Patch by Job Noorman!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168439 91177308-0d34-0410-b5e6-96231b3b80d8
CIB · Nov 21, 2012 · 6cbeb4d · 6cbeb4d
1 parent 6ee1e08
commit 6cbeb4d
Show file tree

Hide file tree

Showing 3 changed files with 72 additions and 17 deletions.
diff --git a/lib/Target/MSP430/MSP430CallingConv.td b/lib/Target/MSP430/MSP430CallingConv.td
@@ -24,6 +24,9 @@ def RetCC_MSP430 : CallingConv<[
 // MSP430 Argument Calling Conventions
 //===----------------------------------------------------------------------===//
 def CC_MSP430 : CallingConv<[
+  // Pass by value if the byval attribute is given
+  CCIfByVal<CCPassByVal<2, 2>>,
+
   // Promote i8 arguments to i16.
   CCIfType<[i8], CCPromoteToType<i16>>,
 

diff --git a/lib/Target/MSP430/MSP430ISelLowering.cpp b/lib/Target/MSP430/MSP430ISelLowering.cpp
@@ -357,22 +357,34 @@ MSP430TargetLowering::LowerCCCArguments(SDValue Chain,
     } else {
       // Sanity check
       assert(VA.isMemLoc());
-      // Load the argument to a virtual register
-      unsigned ObjSize = VA.getLocVT().getSizeInBits()/8;
-      if (ObjSize > 2) {
-        errs() << "LowerFormalArguments Unhandled argument type: "
-             << EVT(VA.getLocVT()).getEVTString()
-             << "\n";
+
+      SDValue InVal;
+      ISD::ArgFlagsTy Flags = Ins[i].Flags;
+
+      if (Flags.isByVal()) {
+        int FI = MFI->CreateFixedObject(Flags.getByValSize(),
+                                        VA.getLocMemOffset(), true);
+        InVal = DAG.getFrameIndex(FI, getPointerTy());
+      } else {
+        // Load the argument to a virtual register
+        unsigned ObjSize = VA.getLocVT().getSizeInBits()/8;
+        if (ObjSize > 2) {
+            errs() << "LowerFormalArguments Unhandled argument type: "
+                << EVT(VA.getLocVT()).getEVTString()
+                << "\n";
+        }
+        // Create the frame index object for this incoming parameter...
+        int FI = MFI->CreateFixedObject(ObjSize, VA.getLocMemOffset(), true);
+
+        // Create the SelectionDAG nodes corresponding to a load
+        //from this parameter
+        SDValue FIN = DAG.getFrameIndex(FI, MVT::i16);
+        InVal = DAG.getLoad(VA.getLocVT(), dl, Chain, FIN,
+                            MachinePointerInfo::getFixedStack(FI),
+                            false, false, false, 0);
       }
-      // Create the frame index object for this incoming parameter...
-      int FI = MFI->CreateFixedObject(ObjSize, VA.getLocMemOffset(), true);
-
-      // Create the SelectionDAG nodes corresponding to a load
-      //from this parameter
-      SDValue FIN = DAG.getFrameIndex(FI, MVT::i16);
-      InVals.push_back(DAG.getLoad(VA.getLocVT(), dl, Chain, FIN,
-                                   MachinePointerInfo::getFixedStack(FI),
-                                   false, false, false, 0));
+
+      InVals.push_back(InVal);
     }
   }
 
@@ -498,9 +510,23 @@ MSP430TargetLowering::LowerCCCCallTo(SDValue Chain, SDValue Callee,
                                    StackPtr,
                                    DAG.getIntPtrConstant(VA.getLocMemOffset()));
 
+      SDValue MemOp;
+      ISD::ArgFlagsTy Flags = Outs[i].Flags;
+
+      if (Flags.isByVal()) {
+        SDValue SizeNode = DAG.getConstant(Flags.getByValSize(), MVT::i16);
+        MemOp = DAG.getMemcpy(Chain, dl, PtrOff, Arg, SizeNode,
+                              Flags.getByValAlign(),
+                              /*isVolatile*/false,
+                              /*AlwaysInline=*/true,
+                              MachinePointerInfo(),
+                              MachinePointerInfo());
+      } else {
+        MemOp = DAG.getStore(Chain, dl, Arg, PtrOff, MachinePointerInfo(),
+                             false, false, 0);
+      }
 
-      MemOpChains.push_back(DAG.getStore(Chain, dl, Arg, PtrOff,
-                                         MachinePointerInfo(),false, false, 0));
+      MemOpChains.push_back(MemOp);
     }
   }
 

diff --git a/test/CodeGen/MSP430/byval.ll b/test/CodeGen/MSP430/byval.ll
@@ -0,0 +1,26 @@
+; RUN: llc < %s | FileCheck %s
+
+target datalayout = "e-p:16:16:16-i8:8:8-i16:16:16-i32:16:32-n8:16"
+target triple = "msp430---elf"
+
+%struct.Foo = type { i16, i16, i16 }
+@foo = global %struct.Foo { i16 1, i16 2, i16 3 }, align 2
+
+define i16 @callee(%struct.Foo* byval %f) nounwind {
+entry:
+; CHECK: callee:
+; CHECK: mov.w 2(r1), r15
+  %0 = getelementptr inbounds %struct.Foo* %f, i32 0, i32 0
+  %1 = load i16* %0, align 2
+  ret i16 %1
+}
+
+define void @caller() nounwind {
+entry:
+; CHECK: caller:
+; CHECK: mov.w &foo+4, 4(r1)
+; CHECK-NEXT: mov.w &foo+2, 2(r1)
+; CHECK-NEXT: mov.w &foo, 0(r1)
+  %call = call i16 @callee(%struct.Foo* byval @foo)
+  ret void
+}