Path: csiph.com!xmission!news.snarked.org!border2.nntp.dca1.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: George Neuner Newsgroups: comp.compilers Subject: Re: C compiler pointer management on DSPs Date: Thu, 03 Oct 2019 01:34:28 -0400 Organization: A noiseless patient Spider Lines: 20 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <19-10-002@comp.compilers> References: <19-09-003@comp.compilers> <19-09-004@comp.compilers> <19-09-006@comp.compilers> <19-09-007@comp.compilers> <19-09-009@comp.compilers> <19-09-015@comp.compilers> <19-09-017@comp.compilers> <19-09-018@comp.compilers> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="20494"; mail-complaints-to="abuse@iecc.com" Keywords: C, architecture Posted-Date: 04 Oct 2019 11:27:33 EDT X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com Xref: csiph.com comp.compilers:2372 On Sun, 29 Sep 2019 10:53:35 +0200, David Brown wrote: >I can't think of any application where 48-bit would such a natural fit >that you'd have it as your basic access unit. Some video DSP's have >used 48-bit units, but that is for a vector of 3 16-bit colour units. Analog Devices SHARC series floating point DSPs had 48-bit instructions and 40-bit extended precision floats aligned at 48-bit addresses (probably to use the same address generator as for code). Nominally, though, it was a 16/32 bit device: integer data, including chars could be 16 or 32 bits, and ordinary (single precision) floats were 32 bits. Admittedly, I never encountered any use for the extended floats, but I assumed they were there for a reason. YMMV, George