On Mon, 2 Oct 2006, Jan van Dijk wrote: > On Monday 02 October 2006 12:57, Joseph S. Myers wrote: > > On Mon, 2 Oct 2006, Jan van Dijk wrote: > > > * the C99 and C++ standards say *nothing* about the details of compex > > > multiplication > > > > The C99 standard says that real operands aren't converted to complex, but > > as I note in bug 24581, the compiler doesn't expect PLUS_EXPR and > > MULT_EXPR to have arguments of different types, so the front ends might > > need adapting to handle real * complex and real + complex specially. > > Dear Joseph, > > My question was a slightly different one. To me it is not clear whether the > standard allows the treatment of (r,0) as r in complex operations. For > example: is it allowed to handle (r,0)*(x,y) as r*(x,y)?
I don't think so; at least, it might affect negative 0. > I repeat my previous mail: there does not seem to be consensus about what > standard(s) to implement (Annex G? LIA-x,...), and how to interpret the free > space in those documents. Could you clarify? Annex G, but without imaginary types for now. (I don't have enough information to tell whether they are useful or desirable.) > Triggered by 1*(Inf,0) = (Inf,NaN), I looked inside the compiler for the > first (Inf,NaN) is a valid complex infinity just as (Inf,0) is; see G.3. -- Joseph S. Myers [EMAIL PROTECTED]
