Path: utzoo!attcan!uunet!world!esegue!compilers-sender
From: pardo@cs.washington.edu (David Keppel)
Newsgroups: comp.compilers
Subject: Re: Compiling for DSP chips
Keywords: C, optimize, DSP
Message-ID: <13148@june.cs.washington.edu>
Date: 26 Sep 90 23:13:03 GMT
References: <9009071606.AA22759@m2.csc.ti.com> <1990Sep11.075042.937@funet.fi> <4751@taux01.nsc.com>
Sender: compilers-sender@esegue.segue.boston.ma.us
Reply-To: pardo@cs.washington.edu (David Keppel)
Organization: University of Washington, Computer Science, Seattle
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In article <4751@taux01.nsc.com> avi@taux01.nsc.com (Avi Bloch) writes:
>[Compiler that optimizes for special instructions.]

The moderator writes:
>[GCC lets you in-line assembler, frequently hidden inside macros, that is
>often used to get to features like sin and cos instructions. -John]

In particular, you can tell GCC that certain hard registers are
clobbered, so GCC can perform register allocation around those
instructions.  If the machine description knows about those
instructions, then I think that it is also possible to define
optimizations over those instructions, even if the compiler itself
doesn't ``know'' how to emit them.

	;-D on  ( A compile of things to do )  Pardo
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