From: Richard Harvey Chapman <hchapman-gcc-help@3gfp.com>
To: gcc <gcc-help@gcc.gnu.org>
Subject: Re: regarding type promotion
Date: Tue, 19 Aug 2008 16:45:00 -0000 [thread overview]
Message-ID: <48AAF5C8.7010909@3gfp.com> (raw)
In-Reply-To: <1219162574.6008.7.camel@bob-desktop>
Bob Plantz wrote:
> Another rule I gave them is "multiplication and division have higher
> precedence than addition and subtraction; use parentheses in all other
> cases."
++
I used to always get tripped up in embedded code because "==" has
precedence over "&" which I do not believe is intuitive to most people.
unsigned int value;
#define BITSET 0x1234
// Wrong: always true if value is odd since BITSET == BITSET is
evaluated first
// which reduces to "(value & 1)"
if (value & BITSET == BITSET) {} // Bits are set
// Right:
if ((value & BITSET) == BITSET) {} // Bits are set
prev parent reply other threads:[~2008-08-19 16:34 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-19 8:38 Sivaprasad.pv
2008-08-19 13:24 ` Andrew Haley
2008-08-19 15:35 ` Eljay Love-Jensen
2008-08-19 16:33 ` Bob Plantz
2008-08-19 16:34 ` Richard Harvey Chapman
2008-08-19 17:02 ` Ian Lance Taylor
2008-08-19 22:07 ` Richard Harvey Chapman
2008-08-20 2:28 ` Ian Lance Taylor
2008-08-19 22:36 ` Richard Harvey Chapman
2008-08-19 16:45 ` Richard Harvey Chapman [this message]
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