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[Bug tree-optimization/54717] [4.8 Regression] Runtime regression: polyhedron test "rnflow" degraded
- From: "dominiq at lps dot ens.fr" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 02 Oct 2012 20:23:42 +0000
- Subject: [Bug tree-optimization/54717] [4.8 Regression] Runtime regression: polyhedron test "rnflow" degraded
- Auto-submitted: auto-generated
- References: <bug-54717-4@http.gcc.gnu.org/bugzilla/>
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54717
--- Comment #8 from Dominique d'Humieres <dominiq at lps dot ens.fr> 2012-10-02 20:23:42 UTC ---
Created attachment 28333
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28333
bzipped tar archive of a reduced test
The tar archive contains the files
cptrf2_inl_1.f90 rnflow.in rnflow_red.f90 rnfprm.h
and can be used as in
[macbook] dbg_rnflow/pr54717% gfc -c -Ofast -funroll-loops rnflow_red.f90
[macbook] dbg_rnflow/pr54717% gfc -c -O2 cptrf2_inl_1.f90
[macbook] dbg_rnflow/pr54717% gfc rnflow_red.o cptrf2_inl_1.o
[macbook] dbg_rnflow/pr54717% time a.out > /dev/null
21.036u 0.051s 0:21.09 99.9% 0+0k 0+0io 0pf+0w
[macbook] dbg_rnflow/pr54717% gfc -c -O2 -ftree-loop-if-convert
cptrf2_inl_1.f90
[macbook] dbg_rnflow/pr54717% gfc rnflow_red.o cptrf2_inl_1.o
[macbook] dbg_rnflow/pr54717% time a.out > /dev/null
27.150u 0.051s 0:27.20 100.0% 0+0k 0+0io 0pf+0w
This shows that the file cptrf2_inl_1.f90 compiled with -ftree-loop-if-convert
gives a slow executable without involving inlining or vectorization.