1445194 - [meta] Remove some LIR/MIR boilerplate

Status: RESOLVED FIXED

(Core :: JavaScript Engine: JIT, enhancement, P3)

Description

[Jan de Mooij [:jandem]]

With bug 1445181 and bug 1425580 fixed, I think we should consider moving all visitFoo methods currently defined in platform-specific files to Lowering.h/CodeGenerator.h so we can use a macro to define them automatically. The definitions could still live in platform-specific cpp files.

I also wonder if we should use a build-time script to generate the MOpcodes/LOpcodes header files automatically based on the INSTRUCTION_HEADER macros in MIR.h and the LIR files.

Then when we add a new instruction, we no longer have to touch Lowering.h, CodeGenerator.h, MOpcodes.h, LOpcodes-shared.h - we just have to add classes to MIR.h and LIR-shared.h and define the Lowering.cpp and CodeGenerator.cpp code.

Comment 1

[Jan de Mooij [:jandem]]

What do you think?

Comment 2

[Nicolas B. Pierron [:nbp]]

I think this is a good idea to have a single file which does the big switches over the instruction definitions.

Generating the LOpcodes and MOpcodes from the INSTRUCTION_HEADER should be easy to do, with potentially a tiny bit of complexity for platform specific LIR instruction.

Comment 3

[Jan de Mooij [:jandem]]

Making this more of a meta bug.

Also, we currently pass operands/temps to LIR instruction constructors - there might be a nicer design where lowering calls setTemp/setOperand somehow so that we don't need to pass this data to all the constructors.

Comment 4

[Jan de Mooij [:jandem]]

So what's described in comment 0 is done now: adding/removing an instruction no longer requires touching MOpcodes.h, LOpcodes.h, Lowering.h, CodeGenerator.h.

I'll keep this open because there's more code in the LIR classes I want to try to get rid of. My goal is for LIR classes to be really simple and short.

Comment 5

[Caroline Cullen [:caroline]]

Since we are now going to be auto generating the boilerplate I'm going to close this.