Open Projects - Code Generator Improvements #2

Project Infrastructure LLVM Dev List Archives
1

Hello,

I am a student at UFMG, Brazil, and I’m currently choosing my final undergraduate project.

I will be working under Professor Fernando Pereira (on cc), and we were thinking about tackling Code Generator Improvement number 2 (at http://llvm.org/OpenProjects.html).

How is the status on this project? Is it still open?

Thanks for your time,
Thiago Martins.

2

For reference, that is

3

We do have an existing stack coloring pass which runs on allocas. My understanding is that it's not very effective and relies on the existence of lifetime markers (i.e. it doesn't actually do any liveness analysis).

I know that Keno Fischer has spent some time looking at the existing pass. I believe he was chasing down a mis-compile, but he's probably the most recent person to look at it.

See: lib/CodeGen/StackColoring.cpp

A very useful first step would be to consider merging StackColoring.cpp and StackSlotColoring.cpp.

Philip

4

From: "Philip Reames via llvm-dev" <llvm-dev@lists.llvm.org>
To: "Rafael Espíndola" <rafael.espindola@gmail.com>, "Thiago Martins" <thiagomartinsbh@gmail.com>
Cc: "llvm-dev" <llvm-dev@lists.llvm.org>, "Fernando Magno Quintao Pereira" <fernando@dcc.ufmg.br>
Sent: Thursday, January 21, 2016 3:40:12 PM
Subject: Re: [llvm-dev] Open Projects - Code Generator Improvements #2

We do have an existing stack coloring pass which runs on allocas. My
understanding is that it's not very effective and relies on the
existence of lifetime markers (i.e. it doesn't actually do any
liveness
analysis).

I know that Keno Fischer has spent some time looking at the existing
pass. I believe he was chasing down a mis-compile, but he's probably
the most recent person to look at it.

See: lib/CodeGen/StackColoring.cpp

A very useful first step would be to consider merging
StackColoring.cpp
and StackSlotColoring.cpp.

I agree.

-Hal

P.S. I've not really done much work on this, except that I'm responsible for the bug fix that allows this to work along with a backend use of alias analysis (one of those fixes that makes one cringe).