Re: Unnamed pattern in .md file

[Alan Lehotsky <lehotsky at tiac dot net>]

At 4:04 PM -0700 5/16/00, Desmond Cheung wrote:
>Hi,
>
>I'm writing the configuration files (.md, .h, .c) for a machine.
>
>When do we define unnamed patterns in the .md file?
>Why do we need them? Just for optimization?
>Can the .md file be without any unnamed patterns?
>
>Thanks.
>
>Des


	The only patterns that MUST be named are those that are used
	to generate RTL from the front-end parser.  These are all
	described in the Porting GCC doc.

	Otherwise, you name patterns if

	1/ You want to be able to use them as construction subroutines
	   by calling gen_XXXX(op0, op1, ...) yourself - either from within
	   a named pattern that the front-ends know about, or by a splitter.

	2/ You want to have a mnemonic handle on the pattern for
	   debugging.

	Any code-generation pattern that matches RTL that was created
	by a named pattern (frequently a define_expand), or that matches
	a sequence of RTL created by one or more tree-to-RTL conversions
	can be unnamed.

	Off the top of my head, I can't think of any other reasons
	to name patterns?

-- Al
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