Huomautus
Tämän sivun käyttö edellyttää valtuutusta. Voit yrittää kirjautua sisään tai vaihtaa hakemistoa.
Tämän sivun käyttö edellyttää valtuutusta. Voit yrittää vaihtaa hakemistoa.
Returns the location of the first set bit starting from the lowest order bit and working upward, per component. This intrinsic corresponds to the DXBC instruction firstbit_lo.
Syntax
int firstbitlow(
in int value
);
Parameters
-
value [in]
-
Type: int
The input value.
Return value
Type: int
The location of the first set bit.
The location is a zero-based count (or index), starting from the least significant bit (LSB). So you can use 1U << firstbitlow(value) to recreate the corresponding bit found. When no bit is set in the input, the return value is 0xFFFFFFFF (all bits set). Endian-ness isn't relevant here; only bit significance in the integer (not in the memory layout).
Remarks
The following overloaded versions are also available:
uint2 firstbitlow(uint2 value);
uint3 firstbitlow(uint3 value);
uint4 firstbitlow(uint4 value);
Minimum shader model
This function is supported in the following shader models.
| Shader model | Supported |
|---|---|
| Shader Model 5 and higher shader models | yes |
This function is supported in the following types of shaders:
| Vertex | Hull | Domain | Geometry | Pixel | Compute |
|---|---|---|---|---|---|
| x | x | x | x | x | x |