https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68682
Bug ID: 68682
Summary: [6 Regression] [graphite] loop interchange no longer
working after r227277
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: dominiq at lps dot ens.fr
CC: spop at gcc dot gnu.org
Target Milestone: ---
Up to revision r227276, compiling the test at
https://gcc.gnu.org/bugzilla/attachment.cgi?id=32703 (pr60997) with '-Ofast
-floop-interchange' gave the following timings
94378416668672.000
Elapsed time = 0.55861600000000000 seconds
94378416668672.000
Elapsed time = 0.56767100000000004 seconds
94378416668672.000
Elapsed time = 0.54659700000000000 seconds
94378416668672.000
Elapsed time = 0.54611900000000002 seconds
At r227277 this becomes with -floop-nest-optimize
94378416668672.000
Elapsed time = 1.3123039999999999 seconds
94378416668672.000
Elapsed time = 0.53941300000000003 seconds
94378416668672.000
Elapsed time = 1.4528440000000000 seconds
94378416668672.000
Elapsed time = 0.54144199999999998 seconds
then
94378416668672.000
Elapsed time = 6.8884299999999996 seconds
94378416668672.000
Elapsed time = 0.54318699999999998 seconds
94378416668672.000
Elapsed time = 6.8123120000000004 seconds
94378416668672.000
Elapsed time = 0.54194500000000001 seconds
with r228457 up to r230172 (bad loop exchange) and now (from r230325)
94378416668672.000
Elapsed time = 3.7355589999999999 seconds
94378416668672.000
Elapsed time = 0.54112400000000005 seconds
94378416668672.000
Elapsed time = 6.8592209999999998 seconds
94378416668672.000
Elapsed time = 0.53388500000000005 seconds
i.e., the same timings than with -Ofast alone (no loop exchange).
I am using ISL-0.15 for the latest tests (since Sep 29).
