Il 13/09/2013 17:02, Peter Maydell ha scritto: > On 13 September 2013 15:55, Paolo Bonzini <pbonz...@redhat.com> wrote: >> Il 13/09/2013 15:43, Peter Maydell ha scritto: >>> On 25 August 2013 23:58, Ákos Kovács <akoskov...@gmx.com> wrote: >>>> +eq = $(if $(subst $2,,$1)$(subst $1,,$2),n,y) >>>> +ne = $(if $(subst $2,,$1)$(subst $1,,$2),y,n) >>> >>> These give the wrong answer for comparisons >>> of 'n' with ''. Working versions: >>> >>> eq = $(if $(filter $(call lnot,$1),$(call lnot,$2)),y,n) >>> ne = $(if $(filter $(call lnot,$1),$(call lnot,$2)),n,y) >> >> isempty/notempty are clearly string functions, where only the output is >> of the y/n form. Seeing Akos's implementation of isempty/notempty, I >> think the desired semantics for eq/ne/isempty/notempty are also those of >> string functions. >> >> I would call your functions leqv/lxor, not eq/ne. > > Sounds reasonable -- I was led a little astray by > them all being in a patch whose only documentation > was the phrase "logical functions"... > >> Your patch is fine if you either rename eq/ne like this, >> or revert them to Akos's version. > > It sounds like we probably want two patches: > 1. logical functions: land/lor/leqv/lxor/lnot > 2. string functions: eq/ne/isempty/notempty > > I assume we do end up using eq/ne somewhere?
I cannot think off-hand of a place where I'd use eq/ne directly rather than isempty/notempty. Or for that matter leqv/lxor. :) But since we're discussing the issue and the implementation of eq/ne is not entirely trivial, I think it's simplest to have them even if they are unused for now. Paolo
