develooper Front page | perl.perl5.porters | Postings from March 2013

[perl #117315] [Win32, 5.17.10] infinity is zero

Thread Previous | Thread Next
bulk88 via RT
March 26, 2013 00:52
[perl #117315] [Win32, 5.17.10] infinity is zero
Message ID:
On Mon Mar 25 16:07:35 2013, bulk88 wrote:
> sisyphus can you make a preprocessed (.i) ("-E" for GCC) file of pp.c
> and attach it to this ticket? Use same exactly the same cmd line options
> that were used in the build. I want to see if it was macro-defed to
> something else. A .s asm file made with -S should do it. 
> What OS version are you using?
> A couple of things could have happened. New GCC has inlined pow() which
> is not IEEE 754, or uses 80 bit precision (not likely on Win64, since
> x87 is "deprecated" according to MS) for intermediate results, throws
> and catches FP exceptions, uses 128 bit software precision or libmingwex
> or libgcc are supplying a pow(), and those take priority over the MS c
> lib's pow().

Based on
, mingw has been mucking around *lately* and now offers their own pow()
which "fixes" problems with MS's pow(). I looked at my 64 bit Strawberry
5.14, it does not import pow() from  a MS CRT DLL. Instead a pow (I
can't research it further, since I dont have symbols) is static linked
into the image. My VC 2008 x64 Perl imports pow from a MS CRT DLL.

Based on
 it seems mingw override's MS's implementation for C99 compatibility (I
cant find any exact reasoning on google), see also . So the
question is, does Win32 Perl guarantee "C89 FP math" or "C99 FP math"? I
can't answer that.

bulk88 ~ bulk88 at

via perlbug:  queue: perl5 status: rejected

Thread Previous | Thread Next Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at | Group listing | About