private static Node HandleCallWindowsAbi(IntrusiveList <Node> nodes, StackAllocator stackAlloc, Node node, Operation operation)
{
Operand dest = operation.Destination;
// Handle struct arguments.
int retArgs = 0;
int stackAllocOffset = 0;
int AllocateOnStack(int size)
{
// We assume that the stack allocator is initially empty (TotalSize = 0).
// Taking that into account, we can reuse the space allocated for other
// calls by keeping track of our own allocated size (stackAllocOffset).
// If the space allocated is not big enough, then we just expand it.
int offset = stackAllocOffset;
if (stackAllocOffset + size > stackAlloc.TotalSize)
{
stackAlloc.Allocate((stackAllocOffset + size) - stackAlloc.TotalSize);
}
stackAllocOffset += size;
return(offset);
}
Operand arg0Reg = null;
if (dest != null && dest.Type == OperandType.V128)
{
int stackOffset = AllocateOnStack(dest.Type.GetSizeInBytes());
arg0Reg = Gpr(CallingConvention.GetIntArgumentRegister(0), OperandType.I64);
Operation allocOp = new Operation(Instruction.StackAlloc, arg0Reg, Const(stackOffset));
nodes.AddBefore(node, allocOp);
retArgs = 1;
}
int argsCount = operation.SourcesCount - 1;
int maxArgs = CallingConvention.GetArgumentsOnRegsCount() - retArgs;
if (argsCount > maxArgs)
{
argsCount = maxArgs;
}
Operand[] sources = new Operand[1 + retArgs + argsCount];
sources[0] = operation.GetSource(0);
if (arg0Reg != null)
{
sources[1] = arg0Reg;
}
for (int index = 1; index < operation.SourcesCount; index++)
{
Operand source = operation.GetSource(index);
if (source.Type == OperandType.V128)
{
Operand stackAddr = Local(OperandType.I64);
int stackOffset = AllocateOnStack(source.Type.GetSizeInBytes());
nodes.AddBefore(node, new Operation(Instruction.StackAlloc, stackAddr, Const(stackOffset)));
Operation storeOp = new Operation(Instruction.Store, null, stackAddr, source);
HandleConstantCopy(nodes, nodes.AddBefore(node, storeOp), storeOp);
operation.SetSource(index, stackAddr);
}
}
// Handle arguments passed on registers.
for (int index = 0; index < argsCount; index++)
{
Operand source = operation.GetSource(index + 1);
Operand argReg;
int argIndex = index + retArgs;
if (source.Type.IsInteger())
{
argReg = Gpr(CallingConvention.GetIntArgumentRegister(argIndex), source.Type);
}
else
{
argReg = Xmm(CallingConvention.GetVecArgumentRegister(argIndex), source.Type);
}
Operation copyOp = new Operation(Instruction.Copy, argReg, source);
HandleConstantCopy(nodes, nodes.AddBefore(node, copyOp), copyOp);
sources[1 + retArgs + index] = argReg;
}
// The remaining arguments (those that are not passed on registers)
// should be passed on the stack, we write them to the stack with "SpillArg".
for (int index = argsCount; index < operation.SourcesCount - 1; index++)
{
Operand source = operation.GetSource(index + 1);
Operand offset = new Operand((index + retArgs) * 8);
Operation spillOp = new Operation(Instruction.SpillArg, null, offset, source);
HandleConstantCopy(nodes, nodes.AddBefore(node, spillOp), spillOp);
}
if (dest != null)
{
if (dest.Type == OperandType.V128)
{
Operand retValueAddr = Local(OperandType.I64);
nodes.AddBefore(node, new Operation(Instruction.Copy, retValueAddr, arg0Reg));
Operation loadOp = new Operation(Instruction.Load, dest, retValueAddr);
node = nodes.AddAfter(node, loadOp);
operation.Destination = null;
}
else
{
Operand retReg = dest.Type.IsInteger()
? Gpr(CallingConvention.GetIntReturnRegister(), dest.Type)
: Xmm(CallingConvention.GetVecReturnRegister(), dest.Type);
Operation copyOp = new Operation(Instruction.Copy, dest, retReg);
node = nodes.AddAfter(node, copyOp);
operation.Destination = retReg;
}
}
operation.SetSources(sources);
return(node);
}
private static void HandleLoadArgumentWindowsAbi(
CompilerContext cctx,
IntrusiveList <Node> nodes,
Node node,
Operand[] preservedArgs,
Operation operation)
{
Operand source = operation.GetSource(0);
Debug.Assert(source.Kind == OperandKind.Constant, "Non-constant LoadArgument source kind.");
int retArgs = cctx.FuncReturnType == OperandType.V128 ? 1 : 0;
int index = source.AsInt32() + retArgs;
if (index < CallingConvention.GetArgumentsOnRegsCount())
{
Operand dest = operation.Destination;
if (preservedArgs[index] == null)
{
Operand argReg, pArg;
if (dest.Type.IsInteger())
{
argReg = Gpr(CallingConvention.GetIntArgumentRegister(index), dest.Type);
pArg = Local(dest.Type);
}
else if (dest.Type == OperandType.V128)
{
argReg = Gpr(CallingConvention.GetIntArgumentRegister(index), OperandType.I64);
pArg = Local(OperandType.I64);
}
else
{
argReg = Xmm(CallingConvention.GetVecArgumentRegister(index), dest.Type);
pArg = Local(dest.Type);
}
Operation copyOp = new Operation(Instruction.Copy, pArg, argReg);
cctx.Cfg.Entry.Operations.AddFirst(copyOp);
preservedArgs[index] = pArg;
}
Operation argCopyOp = new Operation(dest.Type == OperandType.V128
? Instruction.Load
: Instruction.Copy, dest, preservedArgs[index]);
nodes.AddBefore(node, argCopyOp);
Delete(nodes, node, operation);
}
else
{
// TODO: Pass on stack.
}
}
public static void RunPass(CompilerContext cctx, StackAllocator stackAlloc, out int maxCallArgs)
{
maxCallArgs = -1;
CallConvName callConv = CallingConvention.GetCurrentCallConv();
Operand[] preservedArgs = new Operand[CallingConvention.GetArgumentsOnRegsCount()];
for (BasicBlock block = cctx.Cfg.Blocks.First; block != null; block = block.ListNext)
{
Node nextNode;
for (Node node = block.Operations.First; node != null; node = nextNode)
{
nextNode = node.ListNext;
if (!(node is Operation operation))
{
continue;
}
HandleConstantCopy(block.Operations, node, operation);
HandleSameDestSrc1Copy(block.Operations, node, operation);
HandleFixedRegisterCopy(block.Operations, node, operation);
switch (operation.Instruction)
{
case Instruction.Call:
// Get the maximum number of arguments used on a call.
// On windows, when a struct is returned from the call,
// we also need to pass the pointer where the struct
// should be written on the first argument.
int argsCount = operation.SourcesCount - 1;
if (operation.Destination != null && operation.Destination.Type == OperandType.V128)
{
argsCount++;
}
if (maxCallArgs < argsCount)
{
maxCallArgs = argsCount;
}
// Copy values to registers expected by the function
// being called, as mandated by the ABI.
if (callConv == CallConvName.Windows)
{
node = HandleCallWindowsAbi(block.Operations, stackAlloc, node, operation);
}
else /* if (callConv == CallConvName.SystemV) */
{
node = HandleCallSystemVAbi(block.Operations, node, operation);
}
break;
case Instruction.ConvertToFPUI:
HandleConvertToFPUI(block.Operations, node, operation);
break;
case Instruction.LoadArgument:
if (callConv == CallConvName.Windows)
{
HandleLoadArgumentWindowsAbi(cctx, block.Operations, node, preservedArgs, operation);
}
else /* if (callConv == CallConvName.SystemV) */
{
HandleLoadArgumentSystemVAbi(cctx, block.Operations, node, preservedArgs, operation);
}
break;
case Instruction.Negate:
if (!operation.GetSource(0).Type.IsInteger())
{
node = HandleNegate(block.Operations, node, operation);
}
break;
case Instruction.Return:
if (callConv == CallConvName.Windows)
{
HandleReturnWindowsAbi(cctx, block.Operations, node, preservedArgs, operation);
}
else /* if (callConv == CallConvName.SystemV) */
{
HandleReturnSystemVAbi(block.Operations, node, operation);
}
break;
case Instruction.VectorInsert8:
if (!HardwareCapabilities.SupportsSse41)
{
node = HandleVectorInsert8(block.Operations, node, operation);
}
break;
}
}
}
}