MIPT-JIT-Compiler

Just-in-time arithmetic expressions compiler for ARM processors

Description

The Compiler involves recursive descent parser used for analysis of arithmetic expression that may contain:

1. Integer constants
2. Names of extern integer variables
3. Names of integer functions which can take from 0 to 4 arguments
4. +, -, * operators
5. Subexpressions in brackets

All spaces are ignored.

To compile expression you should pass the following arguments to jit_compile_expression_to_arm function in compiler.cpp:

• expression - expression to calculate
• externs - array of struct's that describes extern variables and functions. (The last element should have zero fields: .name=0 and .pointer=0)
• out_buffer - pointer to the allocated part of memory which contains the machine code of the program. This program calculates the result of expression.

arm-linux-gnueabi-gcc and qemu-arm are required to run the compiler.

Build example:

arm-linux-gnueabi-gcc -lstdc++ -marm -test.c compiler.cpp -o compiler

Execution example:

qemu-arm -L $LINARO_SYSROOT compiler < input_file.txt > output_file.txt

Input format

.vars
ab=1 a=234 y=-1 zsdf=0
.expression
dec((-3))-sum((-28), ((-ab)*(-y)))-((-y)+dec((-a)))+5-(-a)+(-20)

(This functions are declared in test.c file)