Re: programmer optimizations?

Stefan Monnier <monnier@di.epfl.ch>
Sat, 21 Jan 1995 00:57:17 GMT

          From comp.compilers
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[3 earlier articles]
Re: programmer optimizations? jhowat@lucifer.cs.waikato.ac.nz (1995-01-02)
Re: programmer optimizations? jbuck@Synopsys.COM (1995-01-02)
Re: programmer optimizations? eru@tele.nokia.fi (Erkki Ruohtula) (1995-01-11)
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Re: programmer optimizations? monnier@di.epfl.ch (Stefan Monnier) (1995-01-21)
Re: programmer optimizations? synaptx!carambole!daveg@uunet.uu.net (Dave Gillespie) (1995-01-11)
Re: programmer optimizations? det@sw.stratus.com (David Toland) (1995-01-11)
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Re: programmer optimizations? c1veeru@WATSON.IBM.COM (Virendra K. Mehta) (1995-02-02)
[4 later articles]
| List of all articles for this month |
Newsgroups: comp.compilers
From: Stefan Monnier <monnier@di.epfl.ch>
Keywords: optimize
Organization: Ecole Polytechnique Federale de Lausanne
References: 95-01-003 94-12-145 95-01-010
Date: Sat, 21 Jan 1995 00:57:17 GMT

Erkki Ruohtula <eru@tele.nokia.fi> wrote:
] Of course, in most situations all this does not matter much. But I found
] it very surprising that this rather simple code generation task,
] dividing an unsigned 16-bit value by the constant 4, was handled so badly
] by two out of the three C compilers I tried it on. It does not particularly
] inspire one to trust the optimizer of the compiler, if speed matters.
] A bad thing, because it really is much clearer and maintainable to
] write n/4, if that is what you actually mean.


But what kind of compilers were these ?
A lot of compilers for 386 don't care that much about the quality of
the code produced, because the PC market isn't driven by speed !
Most compilers I know of on RISC processors get this kind of division
right.




Stefan
--

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