Skip to content

Instantly share code, notes, and snippets.

View mgaudet's full-sized avatar

Matthew Gaudet mgaudet

View GitHub Profile
@rygorous
rygorous / gist:e0f055bfb74e3d5f0af20690759de5a7
Created May 8, 2016 06:54
A bit of background on compilers exploiting signed overflow
Why do compilers even bother with exploiting undefinedness signed overflow? And what are those
mysterious cases where it helps?
A lot of people (myself included) are against transforms that aggressively exploit undefined behavior, but
I think it's useful to know what compiler writers are accomplishing by this.
TL;DR: C doesn't work very well if int!=register width, but (for backwards compat) int is 32-bit on all
major 64-bit targets, and this causes quite hairy problems for code generation and optimization in some
fairly common cases. The signed overflow UB exploitation is an attempt to work around this.
@kwk
kwk / CMakeLists.txt
Last active July 30, 2025 15:24
Fix for "undefined reference to dlopen" in CMake projects
project(testlink)
add_executable(testlink main.cpp)
target_link_libraries(testlink)
@clintel
clintel / gist:1155906
Created August 19, 2011 02:40
Fenced code in bullet lists with GitHub-flavoured MarkDown??

Fenced code blocks inside ordered and unordered lists

  1. This is a numbered list.

  2. I'm going to include a fenced code block as part of this bullet:

    Code
    More Code