/// <summary>
/// Creates a set of instructions to realize a generic lea operation.
/// </summary>
/// <param name="sourceType">The source address type (pointer or view).</param>
/// <param name="elementIndex">The current element index (the offset).</param>
/// <param name="targetAddressRegister">The allocated target pointer register to write to.</param>
/// <param name="address">The source address.</param>
private void MakeLoadElementAddress(
AddressSpaceType sourceType,
PrimitiveRegister elementIndex,
PrimitiveRegister targetAddressRegister,
PrimitiveRegister address)
{
var elementSize = ABI.GetSizeOf(sourceType.ElementType);
var offsetRegister = AllocatePlatformRegister(out RegisterDescription _);
using (var command = BeginCommand(
PTXInstructions.GetLEAMulOperation(ABI.PointerArithmeticType)))
{
command.AppendArgument(offsetRegister);
command.AppendArgument(elementIndex);
command.AppendConstant(elementSize);
}
using (var command = BeginCommand(
PTXInstructions.GetArithmeticOperation(
BinaryArithmeticKind.Add,
ABI.PointerArithmeticType,
false)))
{
command.AppendArgument(targetAddressRegister);
command.AppendArgument(address);
command.AppendArgument(offsetRegister);
}
FreeRegister(offsetRegister);
}
/// <summary cref="IBackendCodeGenerator.GenerateCode(LoadElementAddress)"/>
public void GenerateCode(LoadElementAddress value)
{
var elementIndex = LoadPrimitive(value.ElementIndex);
var targetAddressRegister = AllocatePlatformRegister(
value,
out RegisterDescription _);
Debug.Assert(value.IsPointerAccess, "Invalid pointer access");
var address = LoadPrimitive(value.Source);
var sourceType = value.Source.Type as AddressSpaceType;
var elementSize = sourceType.ElementType.Size;
var offsetRegister = AllocatePlatformRegister(out RegisterDescription _);
using (var command = BeginCommand(
PTXInstructions.GetLEAMulOperation(Backend.PointerArithmeticType)))
{
command.AppendArgument(offsetRegister);
command.AppendArgument(elementIndex);
command.AppendConstant(elementSize);
}
using (var command = BeginCommand(
PTXInstructions.GetArithmeticOperation(
BinaryArithmeticKind.Add,
Backend.PointerArithmeticType,
false)))
{
command.AppendArgument(targetAddressRegister);
command.AppendArgument(address);
command.AppendArgument(offsetRegister);
}
FreeRegister(offsetRegister);
}
/// <summary cref="IBackendCodeGenerator.GenerateCode(LoadElementAddress)"/>
public void GenerateCode(LoadElementAddress value)
{
var elementIndex = LoadPrimitive(value.Offset);
var targetAddressRegister = AllocatePlatformRegister(
value,
out RegisterDescription _);
Debug.Assert(value.IsPointerAccess, "Invalid pointer access");
var address = LoadPrimitive(value.Source);
var sourceType = value.Source.Type as AddressSpaceType;
var elementSize = sourceType.ElementType.Size;
if (value.Is32BitAccess)
{
// Perform two efficient operations TODO
var offsetRegister = AllocatePlatformRegister(out RegisterDescription _);
using (var command = BeginCommand(
PTXInstructions.GetLEAMulOperation(Backend.PointerArithmeticType)))
{
command.AppendArgument(offsetRegister);
command.AppendArgument(elementIndex);
command.AppendConstant(elementSize);
}
using (var command = BeginCommand(
PTXInstructions.GetArithmeticOperation(
BinaryArithmeticKind.Add,
Backend.PointerArithmeticType,
Backend.Capabilities,
false)))
{
command.AppendArgument(targetAddressRegister);
command.AppendArgument(address);
command.AppendArgument(offsetRegister);
}
FreeRegister(offsetRegister);
}
else
{
// Use an efficient MAD instruction to compute the effective address
using var command = BeginCommand(
PTXInstructions.GetArithmeticOperation(
TernaryArithmeticKind.MultiplyAdd,
Backend.PointerArithmeticType));
command.AppendArgument(targetAddressRegister);
command.AppendArgument(elementIndex);
command.AppendConstant(elementSize);
command.AppendArgument(address);
}
}
