This GitHub repository preserves incredibly early versions of Dennis Ritchie's Portable C Compiler, including pre-1.0 snapshots dating back to the late 1970s. These versions offer a fascinating glimpse into the evolution of C, showcasing its transition from a research language to the widespread programming powerhouse it became. The repository aims to archive these historically significant artifacts, making them available for study and exploration by those interested in the origins and development of C. It includes various versions for different architectures, providing valuable insights into early compiler design and the challenges of portability in the nascent days of Unix.
This project aims to port the Amsterdam Compiler Kit (ACK) to the Cray X-MP supercomputer. The ACK, a retargetable compiler suite popular in the 1980s and early 1990s, is being adapted to generate code for the Cray's unique architecture, including its vector registers and specific instruction set. The current state of the project involves modifying the backend of the C compiler within ACK to target the Cray X-MP. This involves adjusting code generation, register allocation, and other compiler internals to accommodate the Cray's hardware. The project is a work in progress, with the goal of eventually producing a functional C compiler for the Cray X-MP using the ACK framework.
Hacker News users discuss the Amsterdam Compiler Kit (ACK) for the Cray X-MP, primarily focusing on its historical significance and the challenges of porting and maintaining software for such old hardware. Several commenters reminisce about using ACK and similar tools in the past, highlighting the intricacies of vectorization and optimization for Cray architectures. The discussion touches on the complexities of the Cray instruction set, the cleverness of ACK's code generation, and the difficulties in preserving historical software due to bit rot and lack of accessible hardware. Some express interest in exploring the code further, while others contemplate the effort required to get it running on modern systems or emulators. There's also mention of ACK's broader application beyond Cray systems, and its use in other academic and research contexts.
Summary of Comments ( 97 )
https://news.ycombinator.com/item?id=43433030
Hacker News users discussed the historical significance of the rediscovered C compiler source code, noting its use of PDP-11 assembly and the challenges of porting it to modern systems due to its tight coupling with the original hardware. Several commenters expressed interest in its educational value for understanding early compiler design and the evolution of C. Some debated the compiler's true "firstness," acknowledging earlier, possibly lost, versions, while others focused on the practical difficulties of building and running such old code. A few users shared personal anecdotes about their experiences with early C compilers and PDP-11 machines, adding a personal touch to the historical discussion. The overall sentiment was one of appreciation for the preservation and sharing of this piece of computing history.
The Hacker News thread discussing "The earliest versions of the first C compiler known to exist" contains a modest number of comments, primarily focusing on the historical significance of the code and some technical details. No one expresses strong disagreement with the premise of the post.
Several commenters express fascination and appreciation for the historical context of the code. One user notes the importance of seeing these early versions to understand the evolution of the language and compiler technology. Another marvels at the simplicity and directness of the early code, highlighting the limited hardware resources of the time. A few commenters express a sense of nostalgia, reminiscing about their early experiences with C and PDP-11 systems.
There's some discussion of the technical aspects of the compiler, including the use of PDP-11 assembly language and the limited optimization strategies employed. One commenter points out the clear connection between the C code and the generated assembly, emphasizing the straightforward nature of the compilation process in these early versions. Another commenter highlights the comment about the lack of register allocation in the oldest version, explaining how this would impact performance.
A couple of users point out the significance of seeing how features like floating-point support were added incrementally to the compiler. One commenter contrasts the manual optimization efforts required in the past with modern compiler optimization techniques.
A few commenters provide additional historical context or links to related resources. One user links to an oral history of Dennis Ritchie discussing the development of C. Another mentions the book "Lions' Commentary on UNIX 6th Edition," which provides a detailed analysis of an early Unix kernel, including parts written in C using a similar compiler.
Overall, the comments demonstrate a shared appreciation for the historical value of the preserved code, reflecting on the evolution of C and the ingenuity of its early developers. While the discussion isn't extensive, it provides valuable insights and context for understanding the significance of this piece of computing history.