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From: kremer@cs.odu.edu (Lloyd Kremer)
Newsgroups: comp.lang.c
Subject: Re: HELP! Need *detailed* list of Microsoft C 5.1 -> 6.0 changes
Keywords: Silent introduction of BUGS
Message-ID: <1991Jun28.124443.27333@cs.odu.edu>
Date: 28 Jun 91 12:44:43 GMT
Article-I.D.: cs.1991Jun28.124443.27333
References: <1991Jun28.030934.10935@Octopus.COM>
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In article <1991Jun28.030934.10935@Octopus.COM> pete@octopus.COM (Pete Holzmann) writes:
>We just discovered that Microsoft has silently ANSI-fied "thousands" of
>things in their C compiler in moving from version 5.1 to 6.0

I think I found one by accident.  Floats no longer automatically promote to
doubles on evaluation.  Instead the resulting type depends on which type comes
first in the SOURCE code!  For example:

	float f;
	double d;

	sizeof(f) == 4
	sizeof(d) == 8
	sizeof(f + d) == 4
	sizeof(d + f) == 8

Any other arithmetic operator works the same.

This may be an unwanted side effect of their change to let floats be passed to
ANSI-defined functions taking a float parameter.

However, I noticed that for old-style argument passing floats are still passed
on the stack as doubles, if that's any consolation.

					Lloyd Kremer
					Hilton Systems, Inc.
					kremer@cs.odu.edu