[cfe-dev] Parsing benchmark: LibTomMath

[Neil Booth]

Steve Naroff wrote:-

> My only point was it's always going to be hard to do an "apple to  
> apple" comparison. I brought up "Tiny C" as a way to dramatize my point.

As you note, TCC is quite uninteresting at it makes essentially no
attempt to conform to the standard, and doing so would require a
major rewrite and slow it down considerably.

> I am not familiar with LibTomMath - I would guess it isn't header rich.
> 
> If your cfe has a "-E" switch, it might be interesting to see how it  
> compares with clang. If there isn't a big difference in preprocessor  
> performance, we know it is likely to be in the AST building and  
> semantic analysis.

Heh, embarassingly it seems to have "regressed" in the -E department,
with a segfault or two :)  Notably the only area that isn't regtested.

I'm doubtful of the value of the comparison anyway, though, as
e.g. clang takes care to avoid pastes, I do not, and I take care to
preserve the form of whitespace, whereas clang does not.  I've always
felt -E timings are more representive of buffering strategy than
anything else.

Neil.