id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
2338	unpack primitive types by default in data? and NOUNPACK?	Isaac Dupree	simonmar	"We should have a NOUNPACK pragma paralleling UNPACK so that we can unpack data types by default without completely taking away control from the programmer.  (Currently, NOUNPACK would only have any effect when `-funbox-strict-fields` is given.)

We may want to unpack strict primitive types by default (at least with -O), such as in the following
{{{
data D a = D !Int !Double
}}}
(Because those are the types that it's most often useful to pass around in registers, for one thing?)

But it's probably worth testing on a lot of existing code to make sure it's never too much of a penalty in practice.  (But considering the amount that people just use `-funbox-strict-fields` without thinking, because having to place all those UNPACK pragmas is annoying, making the default be a little smarter is probably useful.)

see parts of this thread: http://thread.gmane.org/gmane.comp.lang.haskell.cafe/40294/focus=40316

related tickets, in order of decreasing relatedness: #605, #1349; #1433, #2289"	feature request	closed	high	7.4.1	Compiler	6.8.2	fixed		leuschner@… johan.tibell@… mail@…	Unknown/Multiple	Unknown/Multiple	None/Unknown	Unknown