Hello World!

In this example, we will show you how to use hidet to write a simple “Hello World” program.

Hidet is a deep learning compiler implemented in python. Let’s import it first.

import hidet

Hidet caches all its generated source code and binary in its cache directory. We can set the cache directory to a local directory ./outs/cache so that you can check the generated code and binary.

hidet.option.cache_dir('./outs/cache')

The hidet.lang submodule implements the Hidet Script domain specific language. In this example, we will use attrs variable and printf function from hidet.lang.

from hidet.lang import attrs, printf

A script module is a compilation unit that contains a list of functions defined in it. Inside a script module, we can use hidet.script to define a hidet script function. The following example defines a function named launch that prints a message to the standard output.

with hidet.script_module() as script_module:

    # we use `hidet.script` to decorate a python function to define a hidet script function.
    @hidet.script
    def launch():
        # we use `hidet.lang.attrs` to set the attributes of the function.
        # the following line specify this hidet script function is a public function.
        attrs.func_kind = 'public'

        # print a message to the standard output.
        printf("Hello World!\n")

With the script module defined, we can build the script module with build() method. The returned module is an instance of hidet.runtime.CompiledModule, which contains the compiled binary.

module = script_module.build()

We can directly call the compiled module, in this case the ‘launch’ function would be invoked.

Note

The printed message has not been captured by our documentation generation tool (i.e., sphinx). If you run the script by yourself, you will see the message printed out in your console.

module()

We can also explicitly specify the function to be invoked using module['func_name'](args).

module['launch']()

you can access the source code of the compiled module using module.source().

Note

The function in the source code has a prefix hidet_, which is used to avoid name conflict with standard library functions.

print(module.source(color=True))

#include <stdint.h>
#include <math.h>
#include <hidet/runtime/symbols.h>
#include <hidet/runtime/memory_planner.h>
#include <hidet/runtime/cpu/context.h>
#include <hidet/runtime/cpu/float32.h>
#include <hidet/runtime/logging.h>


DLL void hidet_launch() {
  printf("Hello World!\n");
}