3. Programs and syntax

GPProgram

To execute a program, it must be described. gpgpu-kt uses its own C-like language.

To compile the program you need to call the following function:

val program = context.compile("""
    void main(int i){
        // Hello world?
    }
""".trimIndent())

There is an alternative way with the access to AST:

val ast = GPAst.parse("""
    void main(int i){
        // Hello world?
    }
""".trimIndent())

val program = context.compile(ast)

Executing

The program itself does nothing. It should be launched with some parameters:

• Instances count
• Index offset (optional)
• Mapping for external buffers and variables (more details in Syntax/Externals)

program.execute(
    instances = 100_000,
    "myIntField" to 123,
    "myFloatData" to memoryF
)

Syntax

The gpgpu-kt programs have some limitations and features.

Externals

To indicate that program is waiting memory from outside, the keyword extern is used.

It can be applied to regular fields and arrays.

These are the fields that are specified when the program is executed

extern int myIntField;
extern float[] myFloatData;

void main(int i){
    myFloatData[i] = myIntField * i;
}