optimization/code quality

>There's a rather large switch inside, and the compiler manages to mess up
>its table, and generate eronous code, or backend failures. Which get fixed
>once in a while by using level 3 optimisation. (Hence I knew the time.)
>Supposedly GCC has some of the same features, most compilers are not very
>often exersized at the nopt. level and have relatively more bugs in that
>part.


One of my favorite compiler experiences was with the compiler on a
Concurrent system... when you turned on level 3 optimization, you would
occasionally see a diagnostic message pop up during compilation "I-Overuse
of registers, see manual for more information"


Well, none of the resultant code worked... i saw that message, and said
"it's informational, that can't be it." finally, at the end of my rope, I
looked at the manual for more information, and the note said, basically,
"We didn't get this level of optimization right. It generates bad code."


I called up Concurrent and filed a bug report that read "User is appalled
by the classification of this error message."


-mark
--

Return to the comp.compilers page.
Search the comp.compilers archives again.