On 01/05/10 01:46, Eric Fisher wrote:
Hi,
I found that sometimes -fno-tree-dominator-opts will bring a big speed
promotion. This is because that pass_dominator tries to thread jumps.
But sometimes this will cause that the loop's exit bb does not
dominator its latch bb again. Then pass_complete_unroll is unable to
know the exact number of loop iteration and will not unroll the loop
completely again
Please file a bug report with a complete testcase so that we can see
what's happening rather than trying to speculate.
jeff
