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What is the Strict Aliasing Rule and Why do we care?

(OR Type Punning, Undefined Behavior and Alignment, Oh My!)

What is strict aliasing? First we will describe what is aliasing and then we can learn what being strict about it means.

In C and C++ aliasing has to do with what expression types we are allowed to access stored values through. In both C and C++ the standard specifies which expression types are allowed to alias which types. The compiler and optimizer are allowed to assume we follow the aliasing rules strictly, hence the term strict aliasing rule. If we attempt to access a value using a type not allowed it is classified as undefined behavior(UB). Once we have undefined behavior all bets are off, the results of our program are no longer reliable.

Unfortunately with strict aliasing violations, we will often obtain the results we expect, leaving the possibility the a future version of a compiler with a new optimization will break code we th

I think I’ve figured out most parts of the cubical type theory papers; I’m going to take a shot to explain it informally in the format of Q&As. I prefer using syntax or terminologies that fit better rather than the more standard ones.

Q: What is cubical type theory?

A: It’s a type theory giving homotopy type theory its computational meaning.

Q: What is homotopy type theory then?

A: It’s traditional type theory (which refers to Martin-Löf type theory in this Q&A) augmented with higher inductive types and the univalence axiom.

As tested on Linux:

An SCM_RIGHTS ancillary message is "attached" to the range of data bytes sent in the same sendmsg() call.
However, as always, recvmsg() calls on the receiving end don't necessarily map 1:1 to sendmsg() calls. Messages can be coalesced or split.
The recvmsg() call that receives the first byte of the ancillary message's byte range also receives the ancillary message itself.
To prevent multiple ancillary messages being delivered

Delving into the why's of AXI

**Note: In all below, slave can also mean interconnect

Do we really need back-pressure?
- Yes, you absolutely need backpressure. What happens when two masters want to access the same slave? One has to be blocked for some period of time. Some slaves may only be able to handle a limited number of concurrent operations and take some time to produce a result. As such, backpressure is required.
- B and R channel backpressure is required in the case of contention towards the master. If a master makes burst read requests against two different slaves, one of them is gonna have to wait.
  - Shouldn't a master be prepared to receive the responses for any requests it issues from the moment it makes the request? Aside from the clock crossing issue someone else brought up, and the interconnect issue at the heart of the use of IDs, why should an AXI master ever stall R or B channels?
The master should be prepared, but it only has one R and one B input, so it can't re

Comparison chips (SoCs) table for ESP8266/ESP32/ESP32-S2/ESP32-S3/ESP32-C3/ESP32-C6

A minimal table to compare the Espressif's MCU families.

	ESP8266	ESP32	ESP32-S2	ESP32-S3	ESP32-C3	ESP32-C6
Announcement Date	2014, August	2016, September	2019, September	2020, December

Anti-hype LLM reading list

Goals: Add links that are reasonable and good explanations of how stuff works. No hype and no vendor content if possible. Practical first-hand accounts of models in prod eagerly sought.

Foundational Concepts

	Portable Version KEYS:
	P6Z3T-UYJC9-YAK3F-APN9M-6ZDSD
	FGZPK-93CWX-Q33Y6-D5URV-YXC3X
	9CZQX-9YAQA-PF33L-XVUQH-NSD48
	8RZ3L-H3Y5L-W2RY5-Z5M8N-C7Z2U
	CCZNU-LW3LF-K9V2T-MYZFF-94667
	EWZM6-3W4UX-KH922-C96GK-VGBH2

	Standard Version KEYS:
	4AZNW-S2YHE-LLMWM-J6EL8-7QKDL