Compiler Option: -gen

Sets the backend code emitter.

Syntax
   -gen < backend >

Parameters
   backend
      gas for x86 GAS assembly, gcc for GNU C, gas64 for x86_64 GAS 
      assembly, llvm for LLVM IR.

Description
   The -gen compiler option sets the backend code emitter and assembler.

   -gen gas
      The compiler will emit GAS assembler code to a .asm file which will 
      then be compiled to an object file using 'as'. This is fbc's original 
      x86 code generation backend.

   -gen gcc
      The compiler will emit C code to a .c file which will then be 
      compiled to an .asm file using 'gcc' as a high level assembler. The C 
      backend is intended to make FB portable to more platforms than just 
      x86. This requires gcc to be installed so that fbc can invoke it to 
      compile the C code, also see Installing gcc for -gen gcc.

   -gen gas64
      The compiler will emit GAS assembler code (64-bit) to a .asm file 
      which will then be compiled to an object file using 'as'.

   -gen llvm
      The compiler will emit LLVM IR code to a .ll file which will then be 
      compiled to an .asm file using 'llc'. The LLVM backend is still a 
      work in progress. It is intended for the same purpose as the C 
      backend, and could theoretically solve some of the C backend's 
      problems, such as debugging meta data support.

See also
   * Tools used by fbc
   * Using the Command Line

