------- Comment #2 from tkoenig at netcologne dot de 2010-05-16 19:03 ------- Subject: Re: dot_product / matmul and signed zeros
kargl at gcc dot gnu dot org wrote: > The generated code is fine. The F2003 standard states on page 38. > > The real type includes a zero value. Processors that distinguish > between > positive and negative zeros shall treat them as equivalent > (1) in all relational operations, > (2) as actual arguments to intrinsic procedures other than those > for which it is explicitly specified that negative zero is > distinguished, and > > MATMAL and DOT_PRODUCT are not in the list that (2) applies to. In this case, the negative zero is the _result_; it is not passed as an argument (what's being passed are 0.0 and -1.0, respectively). So, this looks like a question for c.l.f. And yes, there are bugs that are more severe than this ;-) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44156
