Re: Is it possible that gcc reorders a series of read/write operations?

[Robert William Fuller <hydrologiccycle@xxxxxxxxx>]

Pan ruochen wrote:
> I wonder if there is any possibility that gcc reorders the read/write
> operations in a way it thinks more optimal, which may be a disaster to
> the hardware driver.

IIRC, the C compiler is required to maintain program order.  Hence, it 
should not re-order reads and writes.  However, if you do not declare a 
register as volatile, the compiler might optimize away something.  For 
example:

*HW_REG0=1;
*HW_REG0=4;

Might become simply:

*HW_REG0=4;

Rob