Hello, everyone. I will try to make this question as specific as possible.
I am trying to write a vector library in Visual Studio 2008 as an exercise. My hope is to make use of the SSE instructions for operating on packed single-precision floating point values. While it is rather trivial to get the inline assembly to work in native C, I am having trouble getting it to work in C#, which expects managed code. I am trying to work around this problem by creating a DLL in Managed C++ and using the DLLImportAttribute to load the resulting DLL so I can call my routines that use native assembly.
The problem is that as soon as I call any routine, CLR throws a BadImageFormatException right on the spot.
Here is the source code (Written in Managed Visual C++) that I made for the DLL file:
// This is the main DLL file.
#include "stdafx.h"
#include "VectorDLL.h"
struct vector_f
{
float x,y,z,w;
};
vector_f __add(vector_f a, vector_f b)
{
vector_f t;
__asm
{
movups xmm0, a
movups xmm1, b
addps xmm0, xmm1
movups t, xmm0
}
return t;
}
Here is the C# code where I call the routine exposed by the DLL:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Windows.Forms;
namespace Vector
{
public struct vec
{
private float x, y, z, w;
public vec(float x, float y, float z)
{
this.x = x; this.y = y; this.z = z; this.w = 1.0f;
}
public vec(float x, float y, float z, float w)
{
this.x = x; this.y = y; this.z = z; this.w = w;
}
}
class Vector
{
private vec t;
[DllImportAttribute("VectorDLL.dll")] static extern vec __add(vec a, vec b);
public Vector(float x, float y, float z)
{
this.t = new vec(x, y, z);
}
public Vector(float x, float y, float z, float w)
{
this.t = new vec(x, y, z, w);
}
public Vector(vec s)
{
this.t = s;
}
public static Vector operator +(Vector a, Vector b)
{
// Exception thrown here: BadImageFormatException (HRESULT 0x8007000B)
return new Vector(__add(a.t, b.t));
}
}
class Program
{
static void Main(string[] args)
{
Vector a = new Vector(1, 2, 3);
Vector b = new Vector(4, 5, 6);
try
{
Vector c = a + b;
}
catch (DllNotFoundException e)
{
MessageBox.Show(e.Message);
return;
}
catch (EntryPointNotFoundException e)
{
MessageBox.Show(e.Message);
return;
}
Console.ReadLine();
}
}
}
Thanks for your help.
