On Fri, 16 Sep 2005, Ross Ridge wrote: > Joe Buck writes: > > To me, even a 1% performance hit to fix this would be excessive. > > I think any performance hit to support UCNs or extended characters outside > of strings and comments is undesirable. GCC should have an option like > "-trigraphs" for the few programs that need this feature.
I have indeed just submitted a patch to add such an option, -fextended-identifiers. This is however in recognition of the *implementation* being experimental rather than an intention permanently to exclude it from the -std options (including -std=gnu99) which should in principle enable this feature. Naturally the idea would be to avoid performance cost *in the normal case where extended identifiers are not used* from extended identifiers, with all complications from such identifiers being a slow case, just as lexing a??/U??/ ??/ 0??/ 000000??/ ??/ z (as the three tokens a, \, U0000000z, because the UCN syntax is not met) is a slow and rare case (which GCC correctly implements). I do not however see any problem with a 1% (or 10%) slowdown for programs *where a significant proportion of identifiers are extended identifiers* in order to refine the handling of such identifiers. -- Joseph S. Myers http://www.srcf.ucam.org/~jsm28/gcc/ [EMAIL PROTECTED] (personal mail) [EMAIL PROTECTED] (CodeSourcery mail) [EMAIL PROTECTED] (Bugzilla assignments and CCs)
