On 01/14/14 06:42, Richard Biener wrote:
This fixes the slowness seen in LCM compute_available accounted
to RTL cprop. Currently the dataflow problem uses a "random"
basic-block order to seed the initial worklist (it wants to
visit predecessors before successors) - the following patch
makes it use inverted postorder (similar to tree PRE antic
computation).
This reduces the compile-time for the testcase in PR59802 at -O3
from
CPROP : 54.53 (55%) usr 0.04 ( 6%) sys 54.57 (55%)
wall 4444 kB ( 2%) ggc
PRE : 4.47 ( 5%) usr 0.03 ( 5%) sys 4.48 ( 5%)
wall 1833 kB ( 1%) ggc
TOTAL : 98.51 0.63 99.13
220195 kB
to
CPROP : 2.13 ( 5%) usr 0.06 (10%) sys 2.20 ( 5%)
wall 4444 kB ( 2%) ggc
PRE : 0.52 ( 1%) usr 0.02 ( 3%) sys 0.54 ( 1%)
wall 1833 kB ( 1%) ggc
TOTAL : 42.22 0.60 42.81
220195 kB
which is nice. I checked for other compile-time hog PRs with
CPROP but didn't find one, have yet to check for PRE (three-letter,
likely too much noise).
Bootstrap and regtest running on x86_64-unknown-linux-gnu, ok for trunk
(and branch?)
Thanks,
Richard.
2014-01-14 Richard Biener <rguent...@suse.de>
PR rtl-optimization/59802
* lcm.c (compute_available): Use inverted postorder to seed
the initial worklist.
Looks good. Thanks for taking care of this.
Jeff
