Builder programming guide

Often, some kind of templating is required. For example, one might want to create a single and a double-precision variant of the the same kernel, meaning that one needs to replace every occurence of “f32” with “f64”. To faciliate templating in a programmatic way, the builder API (C++) offers an alternative to writing tensor language in textual form. In the builder API, data type objects, value objects, instruction objects, region objects, and function objects are stitched together to form an Abstract Syntax Tree. As such, complex code generation patterns can be realized, e.g. offering different code paths for specific values of a parameterization.

Consider the following simple copy kernel

func @copy(%A: memref<${type}x${M}x${N}>, %B: memref<${type}x${M}x${M}>) {
    axpby.n 1.0, %A, 0.0, %B : ${type}, memref<${type}x${M}x${N}>, ${type}, memref<${type}x${M}x${N}>
}

In the following example we build the above code programmatically and replace the place-holders (${.}) by actual values:

CC++

tinytc_scalar_type_t type = ...;
int64_t M = ...;
int64_t N = ...;

tinytc_data_type_t dt;
int64_t shape[2] = {M, N};
tinytc_memref_type_create(&dt, type, 2, shape, 0, NULL, NULL);

tinytc_value_t A, B, alpha, beta;
tinytc_value_create(&A, dt, NULL);
tinytc_value_create(&B, dt, NULL);
tinytc_float_imm_create(&alpha, 1.0, type, NULL);
tinytc_float_imm_create(&beta, 0.0, type, NULL);
tinytc_data_type_release(dt);

tinytc_inst_t copy_inst;
tinytc_axpby_inst_create(&copy_inst, tinytc_transpose_N, 0, alpha, A, beta, B, NULL);
tinytc_value_release(alpha);
tinytc_value_release(beta);

tinytc_func_t copy_proto;
tinytc_value_t args[2] = {A, B};
tinytc_function_prototype_create(&copy_proto, "copy", 2, args, NULL);
tinytc_value_release(A);
tinytc_value_release(B);

tinytc_region_t copy_body;
tinytc_region_create(&copy_body, 1, &copy_inst, NULL);
tinytc_inst_release(copy_inst);

tinytc_func_t copy_fun;
tinytc_function_create(&copy_fun, copy_proto, copy_body, NULL);
tinytc_func_release(copy_proto);
tinytc_region_release(copy_body);

tinytc_prog_t program;
tinytc_program_create(&program, 1, &copy_fun, NULL);
tinytc_func_release(copy_fun);