Editing BLISS (section)

{{Short description|Systems programming language}}
{{Other uses|Bliss (disambiguation){{!}}Bliss}}
{{Infobox programming language
| name = BLISS
| logo =
| paradigm = [[Structured programming|Structured]], [[Imperative programming|imperative]] ([[Procedural programming|procedural]])
| designer = [[William Wulf|W. A. Wulf]], D. B. Russell, [[Nico Habermann|A. N. Habermann]]
| developer = [[Carnegie Mellon University]]
| released = {{Start date and age|1970}}<!-- If known, add |mm|dd -->
| latest release version = BLISS-64
| latest release date =<!-- {{Start date and age|1970|mm|dd}} -->
| typing = [[Data type|Typeless]]
| scope = [[Scope (computer science)|Lexical]]
| implementations =
| dialects = Common BLISS
| platform = [[PDP-10]], [[PDP-11]], [[VAX]], [[DEC PRISM|PRISM]], [[MIPS architecture|MIPS]], [[DEC Alpha]], [[IA-32]], [[IA-64]], [[x86-64]]
| operating system = [[Cross-platform]]
| license =
| file ext =
| website =
| influenced by = [[ALGOL]]
| influenced =
}}
'''BLISS''' is a [[system programming language]] developed at [[Carnegie Mellon University]] (CMU) by [[William Wulf|W. A. Wulf]], D. B. Russell, and [[Nico Habermann|A. N. Habermann]] around 1970. It was perhaps the best known system language until [[C (programming language)|C]] debuted a few years later. Since then, C became popular and common, and BLISS faded into obscurity. When C was in its infancy, a few projects within [[Bell Labs]] debated the merits of BLISS vs. C.{{citation needed |date=February 2015}}

BLISS is a [[Data type|typeless]] [[Block (programming)|block]]-[[structured programming]] language based on expressions rather than statements, and includes constructs for [[exception handling]], [[coroutine]]s, and [[Macro (computer science)|macros]]. It does not include a [[goto]] statement.

The name is variously said to be short for ''Basic Language for Implementation of System Software'' or ''System Software Implementation Language, Backwards''. However, in his 2015 oral history for the Babbage Institute's Computer Security History Project, Wulf claimed that the acronym was originally based on the name "Bill's Language for Implementing System Software."<ref>{{cite interview |url=https://conservancy.umn.edu/bitstream/handle/11299/178985/oh477waw.pdf?sequence=1&isAllowed=y |title=An Interview with WILLIAM A. WULF OH 477 |first=William A. |last=Wulf |author-link=William Wulf |interviewer=Jeffrey R. Yost |date=June 23, 2015 |location=Charlottesville, Virginia}}</ref>

The original Carnegie Mellon [[compiler]] was notable for its extensive use of [[Optimizing compiler|optimizations]], and formed the basis of the classic book ''[[The Design of an Optimizing Compiler]]''.

[[Digital Equipment Corporation]] (DEC) developed and maintained BLISS compilers for the [[PDP-10]],<ref name="bliss-history">{{cite journal |first=Ronald F. |last=Brender |date=2002 |title=The BLISS programming language: a history |journal=Software: Practice and Experience |volume=32 |issue=10 |pages=955–981 |doi=10.1002/spe.470 |s2cid=45466625 |url=https://www.cs.tufts.edu/~nr/cs257/archive/ronald-brender/bliss.pdf}}</ref> [[PDP-11]],<ref name="bliss-history"/> [[VAX]],<ref name="bliss-history"/> [[DEC PRISM]],<ref>{{cite web |last=MacLaren |first=Don |date=August 27, 1987 |url=http://bitsavers.org/pdf/dec/prism/mica/870827_DECwest_Compiler_Project.pdf |title=DECWest Compiler Project, Description, and Plan |website=Bitsavers.org}}</ref> [[MIPS architecture|MIPS]],<ref name="bliss-history"/> [[DEC Alpha]],<ref name="bliss-history"/> and Intel [[IA-32]],<ref name="bliss-history"/> The language did not become popular among customers and few had the compiler,<ref name="dacruz198870916">{{cite mailing list |last=da Cruz |first=Frank |date=16 September 1987 |url=http://www.columbia.edu/kermit/ftp/e/mail.87a |title=News about Kermit Programs for VAX/VMS |publisher=Kermit Project, Columbia University |mailing-list=Info-Kermit Digest |access-date=5 May 2019 |quote=[[Kermit (protocol)|Kermit-32]] is written in the Bliss language, DEC's "corporate implementation language" (originally developed at CMU). Bliss never gained popularity among DEC's customers; few sites have Bliss compilers.}}</ref> but DEC used it heavily in-house into the 1980s; most of the utility programs for the [[OpenVMS]] [[operating system]] were written in BLISS-32. The DEC BLISS compiler has been ported to the [[IA-64]] and [[x86-64]] architectures as part of the ports of OpenVMS to these platforms.<ref name="bliss-history"/><ref>{{cite web|url=https://www.youtube.com/watch?v=xTaBkCBYskA  |archive-url=https://ghostarchive.org/varchive/youtube/20211221/xTaBkCBYskA |archive-date=2021-12-21 |url-status=live|title=2017 LLVM Developers' Meeting: J. Reagan "Porting OpenVMS using LLVM" |website=[[YouTube]] |date=31 October 2017}}{{cbignore}}</ref> The x86-64 BLISS compiler uses [[LLVM]] as its backend [[code generation (compiler)|code generator]], replacing the proprietary GEM backend used for Alpha and IA-64.