GCC provides support for inline assembly with the following construct: asm ( assembler template : output operands (optional) : input operands (optional) : list of clobbered registers (optional) ); In addition, constraints may be applied to operands to force them to use specific registers or memory addresses. Constrains may be as follows: r any register a %eax b %ebx c %ecx d %edx S %esi D %edi m in memory Numeric same constraint as that numbered input variable See the excellent article in the references below for more information. Article: http://www-106.ibm.com/developerworks/library/l-ia.html Entry created: Wed Mar 19 21:28:22 EST 2003 Entry owner: Michael Still (mikal@stillhq.com) Status: Finalized