Bug in configure script for PPC64 machines
myriachan at cox.net
Wed Jan 31 05:15:41 CET 2007
As "Fuzzy Logic" ran into on January 25, there is a bug in configure for
PowerPC Linux machines. I ran into it as well and diagnosed some of it.
On these machines, "configure" identifies the machine type as
powerpc64-unknown-linux-gnu. This causes it to select the 64-bit assembly
code. However, GCC on these machines is set to do a 32-bit compile by
default. configure recognizes that GCC is 32-bit by default, but it doesn't
switch to using the 32-bit PowerPC assembly code. The result is that "make
check" failed because some code is 32-bit and some code is 64-bit. Unlike
x86-32 and x86-64, such mixed code will compile and link.
Here's the workarounds I found for this:
If you want 32-bit:
./configure --enable-cxx --host=powerpc-unknown-linux-gnu
If you want 64-bit:
./configure --enable-cxx --host=powerpc64-unknown-linux-gnu
The "make distclean" is necessary if you had a failed compile before. If
you get errors in fib_*.c, you didn't do it. --enable-cxx adds the C++
wrapper; delete that if you don't care.
Having both 32-bit and 64-bit on the same machine is possible, but difficult
because gmp.h has definitions that change between the two. You have to
manually edit it, then put the libraries in the correct places on disk.
Considering that the executables on these machines are mostly 32-bit, and
GCC defaults to 32-bit, you'll probably want the 32-bit one.
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