[m-dev.] diff: start of new stack layouts.

[Fergus Henderson]

Tyson Richard DOWD, you wrote:
> 
> Changes to clean up the collection of live value information. Instead of
> requesting shape numbers and outputting .garb files, we store the needed
> information for later processing, so we can generate typeinfos for such
> types later, when we create stack_layout tables.

> +			continuation_info,	
> +					% Information on continuations
> +					% for accurate gc.

> +%	R		continuation_info,	
> +%					% Information on continuations
> +%					% for accurate gc.

I suggest saying "Information on which values are live at continuations
points, for accurate gc".


> +	% live_value_type describes the different sorts of data that
> +	% can be considered live.
> +:- type live_value_type 
> +	--->	succip		% a stored succip
> +	;	curfr		% a stored curfr
> +	;	maxfr		% a stored maxfr
> +	;	redoip
> +	;	hp
> +	;	var(type)	% a variable
> +	;	unwanted.	% something we don't need, or used as
> +				% a placeholder for non-accurate gc.

As mentioned in my earlier mail, var(type) should be var(type, inst)
or something along those lines.

> + at sp 1
> + at item @code{--no-stack-layout}
> +(This option is not intended for general use.)
> +Don't output stack_layout structures or references to them.
> +This option will generate smaller executables, but will not allow the
> +use of the accurate garbage collector.

Hmm, shouldn't `--stack-layout' be disabled by default then?
If it is only useful for accurate GC, then there is no point
enabling it when you're using conservative GC.

You should document that the accurate garbage collector is not yet
implemented.

> New: runtime/mercury_accurate_gc.m
> ===================================================================
> /*
> ** Copyright (C) 1995-1997 University of Melbourne.

s/1995-//

> /*
> ** Conditionally define MR_USE_STACK_LAYOUT.
> **
> ** MR_USE_STACK_LAYOUT can be explicitly turned off with MR_NO_STACK_LAYOUT.
> **
> */

You should document what this #define means.

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Fergus Henderson <fjh at cs.mu.oz.au>   |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>   |  of excellence is a lethal habit"
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