Re: GUB and mpfr/mpc

[Dan Eble]

On Dec 3, 2014, at 07:37 , Masamichi HOSODA <address@hidden> wrote:
> 
>>>>>> I changed mingw.org's mingw-runtime to mingw-64 (32-bit).
>>>>>> Then an error didn't occur and correct test.pdf was generated.
>>>>>> 
>>>>>> https://github.com/trueroad/gub/tree/binutils-2.24
>>>>>> 
>>>>>> I may pull request if you request it.
>>>>>> 
>>>>>> Further, even if the runtime is mingw-w64,
>>>>>> bad_alloc occurred when optimization was turned on.

There is this at the end of skyline.cc:

      // Should add during ver2.19 (to avoid an endless loop
      // when  merging identical skylines with a vertical segment)
      // if (end >= s2->front().end_) s2->pop_front();

Also, the mention of optimization reminds me of one of the horrors of floating 
point types: a value in a register can quietly be changed when it is written to 
memory.  Take a look at some of the “myths” in section 1 of 
https://hal.archives-ouvertes.fr/hal-00128124/en/ .

Do the skylines need to deal with the wide range of values that “double" 
allows?  If not, replacing the Real class with a fixed-point math class would 
make the code a lot less scaring.
— 
Dan