Front page | perl.perl5.porters |
Postings from September 2012
On Tue, Sep 4, 2012 at 2:32 PM, Andy Dougherty <doughera@lafayette.edu> wrote: > On Tue, 4 Sep 2012, Reini Urban wrote: > >> On Tue, Sep 4, 2012 at 9:02 AM, Andy Dougherty <doughera@lafayette.edu> wrote: >> > diff --git a/Configure b/Configure >> > index a1ba981..7fa1804 100755 >> > --- a/Configure >> > +++ b/Configure >> > @@ -19022,11 +19022,10 @@ Revision='$Revision' >> > >> > : check for alignment requirements >> > echo " " >> > -case "$usecrosscompile$multiarch" in >> > +case "$usecrosscompile" in >> > *$define*) >> > $cat <<EOM >> > -You seem to be either cross-compiling or doing a multiarchitecture build, >> > -skipping the memory alignment check. >> > +You seem to be cross-compiling. Skipping the memory alignment check. >> > >> > EOM >> > case "$alignbytes" in >> > @@ -19064,6 +19063,17 @@ EOCP >> > dflt='8' >> > echo "(I can't seem to compile the test program...)" >> > fi >> > + case "$multiarch" in >> > + *$define*) >> > + : The usual safe value is 8, but Darwin with -Duselongdouble >> > + : needs 16. Hence, we will take 8 as a minimum, but allow >> > + : Configure to pick a larger value if needed. >> > + if $test "$dflt" -lt 8; then >> > + dflt='8' >> > + echo "Setting alignment to 8 for multiarch support.">&4 >> > + fi >> > + ;; >> > + esac >> > ;; >> > *) dflt="$alignbytes" >> > ;; >> >> Doesn't solaris with their cc/CC also requires 16? > > I don't understand. This patch is only supposed to set a minimum in the > multiarch case, which is normally just darwin (or NeXT or Rhapsody). The > normal alignbytes test run by Solaris should be unaffected. Sure. But this is merely a documentation issue for cross compilers. And instead of bashing darwin it should be noted that darwin and solaris is right, and linux/freebsd are wrong assuming nothing is done nowadays with SSE. So 16 bytes is a better default than 8 on 64-bit machines. If your machine has SSE (and I bet it has) and you compile your perl with it it will be happily prefering 16. Summary: 8 is an unsafe default value. The wording is misleading. -- Reini Urban http://cpanel.net/ http://www.perl-compiler.org/