(using php-3.0.17RC1)
file functions/fsock.c line 677:

cc: WARNING File = functions/fsock.c, Line = 677
  An unsigned integer is being compared to zero.

size_t _php3_sock_fread(char *ptr, size_t size, int socket)
{
        size_t ret = 0;
        SOCK_FIND_AND_READ_MAX(size);
        
        if(size < 0) return ret;
                ^

irix defines these types:
typedef unsigned int size_t;
typedef int    ssize_t;
or
typedef unsigned long size_t;
typedef long    ssize_t;
(dependent of 32/64 bit interface)
In both cases size_t is unsigned.
Therefore the function _php3_sock_fread()
returns never 0, if there are no data
at the socket to read. This makes socket
communication unusable with irix.