dcl_indexRange (sm4 - asm)
Declares a range of registers that will be accessed by index (an integer computed in the shader).
| dcl_indexRange minRegisterM, maxRegisterN |
|---|
| Item | Description |
|---|---|
| minRegisterM |
[in] The first register to access by index.
|
| maxRegisterN |
[in] The last register to access by index. Same form as minRegister except N is the register number. |
The following restrictions apply to all registers:
- The min and max registers must be the same type and have the same component masks (if masks are declared).
- A register may have multiple index ranges, as long as they do no not overlap.
- The min register number must be less than the max register number.
- An index register cannot contain a system-value.
- Indexing a register outside of the max index declaration produces undefined results.
Pixel shader input registers must use the same interpolation mode; pixel shader output registers are not indexable.
A geometry shader input register has two dimensions (vertex axis, attribute axis); the index range applies only to the attribute axis because the vertex axis is always fully indexable.
This instruction applies to the following shader stages:
| Vertex Shader | Geometry Shader | Pixel Shader |
|---|---|---|
| x | x | x |
This instruction is included to aid in debugging a shader in assembly; you cannot author a shader in assembly language using Shader Model 4.
Example
Here is an example.
dcl_indexRange v1, v3
dcl_indexRange v4, v9
Minimum Shader Model
This function is supported in the following shader models.
| Shader Model | Supported |
|---|---|
| Shader Model 5 | yes |
| Shader Model 4.1 | yes |
| Shader Model 4 | yes |
| Shader Model 3 (DirectX HLSL) | no |
| Shader Model 2 (DirectX HLSL) | no |
| Shader Model 1 (DirectX HLSL) | no |