SN Systems Tech Blog

Filter:

Understanding the performance of code using LLVM's (llvm-mca)

ARTICLE BY: Andrea Di Biagio
POSTED: Dec 13, 2018
TAGS: Compiler, LLVM, Toolchain

LLVM-mca is a LLVM based tool that uses information available in LLVM’s scheduling models to statically measure the performance of machine code in a specific CPU. The goal of this tool is not just to predict the performance of the code when run on the target, but also to help with diagnosing potential performance issues. In this talk we, will discuss how llvm-mca works and walk the audience through example uses of this tool.

READ THE WHOLE POST 

Link time performance

ARTICLE BY: Jamie Redding
POSTED: Jun 20, 2018
TAGS: Developer Services, Linker, Toolchain

When developing console games, linking becomes an inevitable iterative process as changes are made and bugs are fixed. Whilst the C++ file may only be re-compiled once, for example after the file is modified, all of the intermediate files are re-linked, thereby generating the final executable, in every build. Over the course of the development life cycle this can mean having to re-link a game many thousands of times before it finally reaches the consumer. Reducing the overall time each link takes makes a significant impact to the games development process.

READ THE WHOLE POST 

Debugging of optimized code: Extending the lifetime of local variables

ARTICLE BY: Wolfgang Pieb
POSTED: Nov 30, 2017
TAGS: Compiler, Debugger, LLVM, Toolchain

When developing programs, local variables and function parameters are often optimized away by the backend of the compiler to gain the best runtime performance. As a result, these variables and parameters may not be visible when a developer is attempting to debug their optimized programs. For the PS4, game developers commonly write their code with optimizations enabled so they can maintain graphical frame rates (30-60 fps). As such, they regularly encounter loss of debug information, which impacts their productivity. We have introduced an option that forces the various optimization passes to keep local variables and parameters around. This LLVM talk addresses the implementation, effectiveness and performance impact of this feature in front of the LLVM compiler community.

READ THE WHOLE POST