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Roberto Bagnara wrote:Reading the thread "Autoconf manual's coverage of signed integer overflow & portability" I was horrified to discover about GCC's miscompilation of the remainder expression that causes INT_MIN % -1 to cause a SIGFPE on CPUs of the i386 family. Are there plans to fix this bug (which, to me, looks quite serious)? All the best,
Roberto
P.S. I checked whether this bug affects my code and it does. Before yesterday I was completely unsuspecting of such a fundamental flaw... I wonder how many know about it.
It's truly amazing for real code to be computing remainders in this domain ... seems a bad idea to me, since very few people are comfortably aware of what remainder means for such cases.
Everyone knows that dividing a number by -1 or 1 gives a 0 remainder. To the contrary, no one expects a%b to raise SIFPE when b != 0.
-- Prof. Roberto Bagnara Computer Science Group Department of Mathematics, University of Parma, Italy http://www.cs.unipr.it/~bagnara/ mailto:bagnara@cs.unipr.it
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