Related articles |
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Is "register" generally ignored? smeyers@aristeia.com (Scott Meyers) (2002-02-28) |
Re: Is "register" generally ignored? {spamtrap}@erewhon.demon.co.uk (Maneki Neko) (2002-03-09) |
Re: Is "register" generally ignored? fjh@cs.mu.OZ.AU (2002-03-09) |
Re: Is "register" generally ignored? rkrayhawk@aol.com (2002-03-09) |
Re: Is "register" generally ignored? bear@sonic.net (Ray Dillinger) (2002-03-21) |
From: | Maneki Neko <{spamtrap}@erewhon.demon.co.uk> |
Newsgroups: | comp.compilers |
Date: | 9 Mar 2002 02:49:50 -0500 |
Organization: | Compilers Central |
References: | 02-02-067 |
Keywords: | C, optimize |
Posted-Date: | 09 Mar 2002 02:49:50 EST |
Scott Meyers <smeyers@aristeia.com> writes:
[Snip, but he knows about register and &]
> Is it reasonable to assume that contemporary C and C++
> compilers will ignore use of "register" when generating optimized
> code?
No C compiler has ever been *required* to put a register variable in a
physical register, that aspect of 'register' has only ever been a
hint. To see why, simply consider the case of a machine with N
available registers and a piece of code with N+1 simultaneously active
register variables, or the use of 'register' with a non-simple type.
As a practical matter of programming, these days 'register' should be
pronounced 'ensure I don't take the address of this'. Apart from that
specific use, I gave up using register declarations about 10 years
ago.
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