Introduction to the High-Level Shading Language - Introduction to 3D Game Programming with DirectX 9.0 - page 280

ppConstantTable —Returns a pointer to an ID3DXConstant-
Table that contains the constant table data for this shader
Here is an example call of D3DXCompileShaderFromFile :
//
// Compile shader
//

ID3DXConstantTable* TransformConstantTable = 0;
ID3DXBuffer* shader = 0;
ID3DXBuffer* errorBuffer = 0;

hr = D3DXCompileShaderFromFile(
"transform.txt", // shader filename

0,
0,
"Main", // entry point function name

"vs_2_0", // shader version to compile to

D3DXSHADER_DEBUG, // debug compile

&shader,
&errorBuffer,
&TransformConstantTable);

// output any error messages
if( errorBuffer )
{

::MessageBox(0, (char*)errorBuffer->GetBufferPointer(), 0, 0);
d3d::Release<ID3DXBuffer*>(errorBuffer);

}

if(FAILED(hr))
{

::MessageBox(0, "D3DXCreateEffectFromFile() - FAILED", 0, 0);
return false;

}

16.3 Variable Types

Note: In addition to the types that are described in the following
sections, HLSL also has some built-in object types (e.g., texture object).
However, since these object types are primarily used only in the effects
framework, we defer a discussion of them until Chapter 19.

16.3.1 Scalar Types
HLSL supports the following scalar types:

bool —True or false value. Note that HLSL provides the true and
false keywords.

int —32-bit signed integer

half —16-bit floating-point number