README.md

JitFFI

A fast and customizable JIT compiler for FFI (Foreign-Function Interface).

Support

Architecture	Operating System	Calling convention	Compilers	Support
x86-64	Windows	Microsoft x64	MSVC, MinGW	Most
x86-64	Linux	System V AMD64 ABI	GCC	Most

Why Fast and Customizable?

The JitFFI is a compiler which compiles function info to a FFI function.

Call a function with JitFFI = Call a FFI function that JitFFI compiled. So it is fast.

It have many modes to compile, includes:

1. Compile function-info.
2. Compile function-info & arguments.
3. Compile function-info & arguments & function-address. ... and more.

You can let JitFFI to compile in a mode you need. So it is customizable.

Run Example

python ./test.py -t n   # n is the num you want to run.

Compile to Static Library

python ./test.py -c

This command will create a 'libjitffi.a' file.

Usage (in C++)

JitFuncPool is a memory pool, which is executable.

JitFunc is a part of a JitFuncPool, which stands for a function.

To create JitFunc, JitFuncCreater is used.

1. Compile to library.
2. Using #include "jitffi.h" and import this library.

Example Code:

#include "jitffi.h"
#include <stdio.h>

double func(double v)
{
	printf("%lf\n", v);
	return v * 2;
}

int main(void)
{
	using namespace JitFFI;
	using namespace JitFFI::CurrABI;

	ArgTypeList tl = { &atu_double };

	ArgumentInfo info = GetArgInfo(atu_double, tl);

	JitFuncPool jfp(0x1000, JitFuncPool::ReadWrite);
	JitFunc jf(jfp);
	JitFuncCreater jfc(jf);

	auto f = Compile(jfc, info, func);

	double v = 3.14;
	double r;
	const void* dl[] = { &v };
	f(&r, dl);
	printf("%lf\n", r);
}

Command:

python ./test.py -c                 # Create libjitffi.a
g++ test.cpp -L. -ljitffi -o test   # Create test
./test                              # Run test

Usage (in C)

JitFFI has a header file named jitffi_c.h for C program.

All struct/class are packed with jitffi_XXX, and passed by pointer.

Only support CurrABI in C header.

JitFFI::_Platform_::atu_XX in C is jitffi_type_XX.

1. Compile to library. (Add jitffi-c.cpp to source.)
2. Using #include "jitffi-c.h" and import this library.

Example Code:

#include "jitffi-c.h"
#include <stdio.h>

double func(double v)
{
	printf("%lf\n", v);
	return v * 2;
}

int main(void)
{
	jitffi_argtype_ptr tl[] = { jitffi_type_double, NULL };

	jitffi_arginfo *info = jitffi_create_arginfo(jitffi_type_double, tl);

	jitffi_jfp *jfp = jitffi_create_jfp(0x1000, jitffi_readwrite);
	jitffi_jf *jf = jitffi_create_jf(jfp);
	jitffi_jfc *jfc = jitffi_create_jfc(jf);

	jitffi_f2* f = (jitffi_f2*)jitffi_compile(jfc, info, (void*)&func, NULL);

	double v = 3.14;
	double r;
	const void* dl[] = { &v };
	f(&r, dl);
	printf("%lf\n", r);

	jitffi_release_jfc(jfc);
	jitffi_release_jf(jf);
	jitffi_release_jfp(jfp);
}

Command:

python ./test.py -c               # Create libjitffi.a
gcc -c test.c                     # Create test.o
g++ test.o -L. -ljitffi -o test   # Create test
./test                            # Run test