private void EmitIndexComputation(Array array)
{
MemoryMappedStorage mms = GetDataLayout(array);
ArrayMemoryLayout layout = mms.Layout as ArrayMemoryLayout;
if (layout.ElementsPerWord > 1)
{
throw new NotImplementedException("Multiple elements per word not yet implemented");
}
MemoryRegion region = mms.Region;
IMarshalInfo minfo = region.MarshalInfo;
int shiftWidth = MathExt.CeilLog2(mms.Region.AddressWidth);
TypeDescriptor indexType = TypeDescriptor.GetTypeOf(mms.BaseAddress);
for (int i = 0; i < layout.Strides.Length; i++)
{
TypeDescriptor orgIndexType;
if (i > 0)
{
orgIndexType = TypeStack.Skip(1).First();
Emit(_iset.Swap().CreateStk(2, orgIndexType, indexType, indexType, orgIndexType));
}
else
{
orgIndexType = TypeStack.Peek();
}
ulong stride = layout.Strides[layout.Strides.Length - i - 1];
if (MathExt.IsPow2(stride))
{
Emit(_iset.Convert().CreateStk(1, orgIndexType, indexType));
int ishift = MathExt.CeilLog2(stride);
if (ishift > 0)
{
Unsigned shift = Unsigned.FromULong((ulong)ishift, shiftWidth);
TypeDescriptor shiftType = TypeDescriptor.GetTypeOf(shift);
Emit(_iset.LdConst(shift).CreateStk(0, shiftType));
Emit(_iset.LShift().CreateStk(2, indexType, shiftType, indexType));
}
}
else
{
throw new NotImplementedException("Stride ain't a power of 2");
}
if (i > 0)
{
Emit(_iset.Or().CreateStk(2, indexType, indexType, indexType));
}
}
if (mms.BaseAddress.ULongValue != 0)
{
Emit(_iset.LdConst(mms.BaseAddress).CreateStk(0, indexType));
if (minfo.UseStrongPow2Alignment)
{
Emit(_iset.Or().CreateStk(2, indexType, indexType, indexType));
}
else
{
Emit(_iset.Add().CreateStk(2, indexType, indexType, indexType));
}
}
}