Here is a simple test case, demonstrating the issue.

#include <errno.h>
#include <math.h>
#include <stdio.h>

int main(int argc, char *argv[])
{
    printf("%f %d\n", log(-HUGE_VAL), errno);
    printf("%f %d\n", log( HUGE_VAL), errno);
}

result is different for 32- and 64-bit

> cc -xtarget=native log_inf.c -lm ; a.out  
-Inf 33
Inf 33

> cc -xtarget=native64 log_inf.c -lm ; a.out
-NaN 0
Inf 0

#define EDOM 33 in /usr/include/sys/errno.h