Hackers' Pub

Syntax	Description	Examples
`"` keyword `"`	Finds the string within quotes, including spaces. Case-insensitive. (Escape quotes inside with `\"`)	`"Hackers' Pub"`
`from:` handle	Finds content written by the specified user.	`from:hongminhee` `from:hongminhee@hollo.social`
`lang:` ISO 639-1	Finds content written in the specified language.	`lang:en`
`#` tag	Finds content with the specified tag. Case-insensitive.	`#HackersPub`
condition condition	Finds content that satisfies both conditions on either side of the space (logical AND).	`"Hackers' Pub" lang:en`
condition `OR` condition	Finds content that satisfies at least one of the conditions on either side of the OR operator (logical OR).	`#HackersPub OR "Hackers' Pub" lang:en`
`(` condition `)`	Combines the operators within the parentheses first.	`(#HackersPub OR "Hackers' Pub" OR "Hackers Pub") lang:en`

matt godbolt @mattgodbolt@hachyderm.io

12/1/2025, 12:12:58 PM

Public

Day 1 of Advent of Compiler Optimisations!

Why do compilers love `xor eax, eax` for zeroing registers? It's brilliant: saves bytes compared to `mov eax, 0`, AND x86 CPUs recognise this "zeroing idiom" early in the pipeline—breaking register dependencies and removing it from execution entirely. Even better: writing to `eax` zeroes the top 32 bits of `rax` for free, handling 64-bit longs in one instruction.

#AoCO2025

Why xor eax, eax? — Matt Godbolt’s blog

Why do compilers love xor-ing registers so much?

xania.org

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