Chuck Ebbert wrote:
>Matt Mackall wrote:
>
>
>
>
>>FYI, GCC as of 3.2.3 doesn't yet reduce the if(...) form to branchless
>>code but the & and && versions come out the same with -O2.
>>
>>
>
>
> The operands of & can be evaluated in any order, while && requires
>left-to-right and does not evaluate the right operand if the left one
>is false. Only the simplest cases could possibly generate the same
>code.
>
>
>
I have a vague memory of reading a kerneltrap.org article or comment
thread which discussed this. The determination was that a compiler
could choose to fully evaluate the logical expression if there were no
side-effects.
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This archive was generated by hypermail 2b29 : Wed Apr 23 2003 - 22:00:23 EST