Using crosstool scripts i've built under Cygwin the following compilers gcc-4.1.1 and 4.2.0 20061024 (prerelease) for Sparc architecture:
$ ./sparc-unknown-linux-gnu-gcc -v
Using built-in specs.
Target: sparc-unknown-linux-gnu
Configured with: /crosstool-0.43/build/sparc-unknown-linux-gnu/gcc-4.1.1-glibc-2.3.6/gcc-4.1.1/configure --target=sparc-unknown-linux-gnu --host=i686-host_pc-cygwin --prefix=/opt/crosstool/gcc-4.1.1-glibc-2.3.6/sparc-unknown-linux-gnu --with-headers=/opt/crosstool/gcc-4.1.1-glibc-2.3.6/sparc-unknown-linux-gnu/sparc-unknown-linux-gnu/include --with-local-prefix=/opt/crosstool/gcc-4.1.1-glibc-2.3.6/sparc-unknown-linux-gnu/sparc-unknown-linux-gnu --disable-nls --enable-threads=posix --enable-symvers=gnu --enable-__cxa_atexit --enable-languages=c,c++ --enable-shared --enable-c99 --enable-long-long
Thread model: posix
gcc version 4.1.1
and
$ ./sparc-unknown-linux-gnu-gcc -v
Using built-in specs.
Target: sparc-unknown-linux-gnu
Configured with: /crosstool-0.43/build/sparc-unknown-linux-gnu/gcc-4.2-20061024- glibc-2.3.6/gcc-4.2-20061024/configure --target=sparc-unknown-linux-gnu --host=i 686-host_pc-cygwin --prefix=/opt/crosstool/gcc-4.2-20061024-glibc-2.3.6/sparc-un known-linux-gnu --with-headers=/opt/crosstool/gcc-4.2-20061024-glibc-2.3.6/sparc -unknown-linux-gnu/sparc-unknown-linux-gnu/include --with-local-prefix=/opt/cros stool/gcc-4.2-20061024-glibc-2.3.6/sparc-unknown-linux-gnu/sparc-unknown-linux-g nu --disable-nls --enable-threads=posix --enable-symvers=gnu --enable-__cxa_atex it --enable-languages=c,c++ --enable-shared --enable-c99 --enable-long-long
Thread model: posix
gcc version 4.2.0 20061024 (prerelease)
It is necessary for me that i can use in my programs __sync_val_compare_and_swap
function related to the Atomic-Builtins, which supports whith 4.1.* version of gcc.
I try to compile simple C code:
long cmpxchg( long* value, long comp_val, long new_val )
{
return __sync_val_compare_and_swap( value, comp_val, new_val );
}
int main()
{
return 0;
}
But i have the following error: (on both compilers):
$ ./sparc-unknown-linux-gnu-gcc test_cas.c -o test_cas
/tmp/ccREXHsP.o: In function `cmpxchg':
test_cas.c:(.text+0x24): undefined reference to `__sync_val_compare_and_swap_4'
collect2: ld returned 1 exit status
What's the problem? May be i wrong built compilers? May be Sparc architecture (SPARC v8) doesn't support this feature? I tried to compile my another programs - all good (compiled and executed).
As described here: http://gcc.gnu.org/onlinedocs/gcc-4.1.2/gcc/Atomic-Builtins.html __sync_val_compare_and_swap
on some targets will result in a function call (where direct code generation is not available or not yet implemented). That is happening in your case. Assuming that itself is not a problem for you, you then need to link the library which defines __sync_val_compare_and_swap_4
and friends, which I am guessing is libgcc_s (so add -lgcc_s
to your link line).