]Remy X.O. Martin wrote:
I'm CC'ing this back to this list, as there were clearly others who
are interested.
I came across the Shark message that had a large hand in my assuming
that a=b=c type expressions could cause performance issues (on a G5):
"There are a large number of issue stalls caused by data dependencies
within this loop. Issue stalls occur when the result of an
instruction is used by a subsequent instruction before the result has
been calculated. You should re-order the instructions to achieve
better code scheduling or unroll this loop to increase overall
instruction throughput."
To my untrained eye, that second sentence appears to be very
applicable to a=b=c type statements, hence my initial question about
this.
R.
The statement about reordering is for compilers. It is completely
irrelevant for a C programmer, and you should not contort your
code in any way for this or any other similar low level reason.