A Binary Instrumentation Tool
to Analyze Load Instructions in Off-the-Shelf x86-64 Binaries

Table of Contents

1. What is Load Inspector?
2. Citation
3. Tested Configuration
4. Installation
5. Using the Tool
6. Optional Arguments
7. License
8. Contact

What is Load Inspector?

The Load Inspector is a binary instrumentation tool that can analyze load instructions in any off-the-shelf x86(-64) binary to dump various statistics including (but not limited to):

• Number of dynamic loads
• Histogram of dynamic loads based on:
  • Load data size
  • Load addressing mode: PC-relative (aka RIP-relative), stack-relative, register-relative
• Loads that always fetch the same data from the same memory address (aka global-stable loads as per this paper), and their distribution based on :
  • Data size
  • Addressing mode

Load Inspector uses Intel® Software Development Emulator (SDE) API to emulate and instrument any x86(-64) binary running on an Intel processor. Load Inspector also supports the following features out-of-the-box:

• Instrument binaries compiled using advanced (and maybe unsupported by the native machine) x86-64 ISA extensions (e.g., Intel® Advanced Performance Extension (APX) that doubles the architectural registers from 16 to 32).
• Instrument only the regions of interest (ROI) of a binary (or a specific thread of a binary).

Citation

The Load Inspector tool is a part of the following research paper published in ISCA 2024:

Rahul Bera, Adithya Ranganathan, Joydeep Rakshit, Sujit Mahto, Anant V. Nori, Jayesh Gaur, Ataberk Olgun, Konstantinos Kanellopoulos, Mohammad Sadrosadati, Sreenivas Subramoney, and Onur Mutlu, "Constable: Improving Performance and Power Efficiency by Safely Eliminating Load Instruction Execution", In Proceedings of the 51st International Symposium on Computer Architecture (ISCA), 2024

If you find this tool useful for your research, please cite using:

@inproceedings{constable,
  author = {Bera, Rahul and Ranganathan, Adithya and Rakshit, Joydeep and Mahto, Sujit and Nori, Anant V. and Gaur, Jayesh and Olgun, Ataberk and Kanellopoulos, Konstantinos and Sadrosadati, Mohammad and Subramoney, Sreenivas and Mutlu, Onur},
  title = {{Constable: Improving Performance and Power Efficiency
by Safely Eliminating Load Instruction Execution}},
  booktitle = {Proceedings of the 51st International Symposium on Computer Architecture},
  year = {2024}
}

Tested Configuration

The tool has been tested with the following system configuration:

• Ubuntu 22.04.1 LTS, Kernel: 5.15.0-56-generic
• Intel® SDE 9.33
• gcc 11.3.0
• python 3.8.0
• GNU Wget 1.21.2

We have also tested binaries compiled by the following compilers:

• gcc/g++ 11.3.0 (with optimizations for up-to Skylake uArch)
• Clang 18.1.4 (with -mapxf flag for Intel® APX ISA extension)

Installation

Clone the repository:

  git clone https://github.com/CMU-SAFARI/Load-Inspector.git

Run the installation script:

cd Load-Inspector/
./install.sh

This should automatically download the latest version of Intel® SDE and compile the tool using the SDE API.

Using the Tool

First, initialize the shell environment by:

cd Load-Inspector/
source setvars.sh

Compile a test binary:

cd test/fft
make all

Instrument the test binary:

# inspector <optional arguments> -- <target binary> <arguments to target binary>
inspector -- ./fft

This should generate a stats file inspector.stats.txt in the run directory containing all statistics.

Optional Arguments

Load Inspector supports the following optional arguments. To get the full list, run inspector -h:

Argument	Type	Description	Default Value
-o, --output	String	Specifies the output filename prefix.	"inspector"
--dump-loads	Boolean	If provided 1, the tool will dump a CSV file containing all load PCs that are stable across the instrumentation.	0
--start-icount	Integer	If provided non-zero, the tool will start instrumenting the binary from the given instruction count. Zero signifies instrumentation from the beginning.	0
--instr-length	Integer	if provided non-zero, the tool will stop the instrumentation after the given number of instruction has been retired. Zero signifies the instrumentation will continue till the end of the binary.	0
--post-process	Boolean	If provided 1, the tool will post-process the stat file and prepare some high-level charts to visualize the stats.	0

Some Examples

1. To instrument /bin/ls binary with optional arguments -lhrt end-to-end and generate statistics in file named ls_profile:

   inspector -o ls_profile -- /bin/ls -lhrt

2. To dump the PCs of all stable load instructions from test/fft/fft binary in a file named fft_stable_loads:

   inspector -o fft_stable_loads --dump-loads 1 -- test/fft/fft

3. To instrument a region of interest of the test/fft/fft between 3M and 7M instructions:

   inspector --start-icount 3000000 --instr-length 4000000 -- test/fft/fft

License

Distributed under the MIT License. See LICENSE for more information.

Contact

Rahul Bera - [email protected]