Effect of -fno-reorder-blocks?

[David Edelsohn]

>>>>> Hans-Peter Nilsson writes:

Hans-Peter> I see unexpected results with a ss of gcc-3.2 (gcc-20020902).  I
Hans-Peter> get better code with -fno-reorder-blocks *especially*
Hans-Peter> considering effects on the cache (a simple one: 8k unified
Hans-Peter> 1-way, 32-byte lines) for cris-axis-linux-gnu.  I'll add more
Hans-Peter> substance to this claim once I've done more thorough testing,
Hans-Peter> with newer sources, though I believe no changes have been done
Hans-Peter> that would improve this.  I wonder if there are similar effects
Hans-Peter> for other architectures, with more intricate branch timings and
Hans-Peter> cache semantics.  I know about the the messages about SH and
Hans-Peter> -fno-reorder-blocks; that's the reason I tried it.

	This affects PowerPC as well. See PR optmization/6990.

	When I pointed this out to Honza last July , he mentioned that
this type of problem is addressed in the STC implementation on the CFG
branch.  I am not sure about the current status of merging those
improvements. 

David