1The codegen file for the ARM-based JIT is composed by files broken by 2functionality hierarchies. The goal is to separate architectural dependent 3and independent components to facilitate maintenance and future extension. 4 5For example, the codegen file for armv7-a is assembled by the following 6components: 7 8-- 9 10/* Architectural independent building blocks */ 11#include "../CodegenCommon.cpp" 12 13/* Thumb2-specific factory utilities */ 14#include "../Thumb2/Factory.cpp" 15/* Factory utilities dependent on arch-specific features */ 16#include "../CodegenFactory.cpp" 17 18/* Thumb2-specific codegen routines */ 19#include "../Thumb2/Gen.cpp" 20/* Thumb2+VFP codegen routines */ 21#include "../FP/Thumb2VFP.cpp" 22 23/* Thumb2-specific register allocation */ 24#include "../Thumb2/Ralloc.cpp" 25 26/* MIR2LIR dispatcher and architectural independent codegen routines */ 27#include "../CodegenDriver.cpp" 28 29/* Architecture manifest */ 30#include "ArchVariant.cpp" 31 32-- 33 34For the Thumb/Thumb2 directories, each contain the followin three files: 35 36- Factory.c (low-level routines for instruction selections) 37- Gen.c (invoke the ISA-specific instruction selection routines) 38- Ralloc.c (arch-dependent register pools) 39 40The FP directory contains FP-specific codegen routines depending on 41Thumb/Thumb2/VFP/PortableFP: 42 43- Thumb2VFP.c 44- ThumbVFP.c 45- ThumbPortableFP.c 46 47In this way the dependency between generic and specific code tied to 48particular architectures can be explicitly represented. 49