GPgpoesia·Dec 3, 2018Submission
Binary Optimization and Layout Tool by Facebook
2 points · Open discussionfacebookarchive
BOLT
Command Line2018–2022
facebookarchive / BOLT · Archived
BOLT
Binary Optimization and Layout Tool - A linux command-line utility used for optimizing performance of binaries
17Distinct people
17Mentions
0Explicit recommenders
2.5KGitHub stars
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What it is
Binary Optimization and Layout Tool - A linux command-line utility used for optimizing performance of binaries
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This week on Hacker News
Nov 8–Nov 15 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/15/2026, 6:36:16 PM UTC.
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HN mentions by year17 dated mentions
Observed mentions: 2018-06-21 02:34:03 UTC to 2022-11-09 16:55:07 UTC.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2018 | 2018-01-01 00:00:00 UTC | 2019-01-01 00:00:00 UTC | 10 | 6 | 4 |
| 2019 | 2019-01-01 00:00:00 UTC | 2020-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2020 | 2020-01-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 5 | 1 | 4 |
| 2021 | 2021-01-01 00:00:00 UTC | 2022-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 1 | 0 | 1 |
What Hacker News says
10 sourcesBinary Optimization and Layout Tool – Optimizing Performance of Binaries
2 points · Open discussionApplying the BOLT optimiser to Clang for up to 15% performance improvement
2 points · Open discussionOptimizing Clang: A Practical Example of Applying BOLT
48 points · Open discussionCorrect me if I'm wrong, but that architectually seems to be a conventional (profile-guided/feedback-driven) optimizing compiler, except the input "language" is machine code.
For instance, it's peephole optimizations are also a chunk of hand-written C++ code (https://github.com/facebookincubator/BOLT/blob/2ed436a6d3b17...), and thus could benefit just as much from the more declarative (and possibly SMT-driven) ideas in this paper.
Finally, there's all sorts of optimizations that are only possible because of high-level information from the source language. For instance, removing unnecessary loads & stores requires knowing pointers don't alias, which is very difficult to deduce given unannotated integers (most of this is driven by language rules, such as the (controversial) TBAA in C). Additionally, even the BOLT paper itself mentions thing
Read the rest
s that can be understood (and optimized for) from a higher-level language, but are much harder to deduce from a raw binary (Section 8):
> Indirect tail calls are more challenging for static binary rewriters because it is difficult to guess if the target is another function or another basic block of the same function, which could affect the CFG
And, the paper touches on your curiosity in the conclusion:
> Nevertheless, a post-link optimizer has fewer optimizations than a compiler. We show that the strengths of both strategies combine instead of purely overlapping
(Oh, one more post-finally thing, there's probably an argument to be had that BOLT fits into the (backend) superoptimizer category of the paper.)
I think something like BOLT[1] has more promise. Now that I think about it, I'm curious if I take my unoptimized executable, generate the profile for BOLT, then apply BOLT's optimizations, is it possible to come out ahead of the Compiler+BOLT optimizations?
1 - https://github.com/facebookincubator/BOLT
In Future Directions for Optimizing CompilersEach of the passes has a nice comment explaining what it does:
https://github.com/facebookincubator/BOLT/tree/master/src/Pa...
e.g. https://github.com/facebookincubator/BOLT/blob/master/src/Pa...
In Bolt: A Practical Binary Optimizer for Data Centers and BeyondBOLT: A Linux command-line utility used for optimizing performance of binaries
1 points · Open discussionBOLT: A Facebook tool to optimize binaries
1 points · Open discussion