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* [Bug tree-optimization/49730] New: loop not vectorized if inside another loop @ 2011-07-13 10:43 vincenzo.innocente at cern dot ch 2011-07-13 11:24 ` [Bug tree-optimization/49730] " rguenth at gcc dot gnu.org ` (2 more replies) 0 siblings, 3 replies; 4+ messages in thread From: vincenzo.innocente at cern dot ch @ 2011-07-13 10:43 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49730 Summary: loop not vectorized if inside another loop Product: gcc Version: 4.7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned@gcc.gnu.org ReportedBy: vincenzo.innocente@cern.ch I've this simple double loop (used in benchmark) the inner loop (sloop) is not vectorized when invoked inside the longer loop (dloop) c++ -Ofast -c vectdloop.cc -ftree-vectorizer-verbose=7 vectdloop.cc:9: note: Profitability threshold = 6 vectdloop.cc:9: note: Profitability threshold is 6 loop iterations. vectdloop.cc:9: note: LOOP VECTORIZED. vectdloop.cc:7: note: vectorized 1 loops in function. vectdloop.cc:20: note: not vectorized: unexpected loop form. vectdloop.cc:16: note: vectorized 0 loops in function. #include<cmath> inline float fn(float x) { return 2.f*x+std::sqrt(x); } void sloop(float * __restrict__ s, float const * __restrict__ xx) { const int ls=16; for (int j=0; j < ls; ++j) { s[j] = fn(xx[j]); } } int dloop(float yyy) { int niter = 100000; float x = 0.5f; yyy=0; const int ls=16; for (int i=0; i < niter; ++i) { float s[ls]; float xx[ls]; for (int j=0; j < ls; ++j) xx[j] =x+(5*(j&1)); sloop(s,xx); // for (int j=0; j < ls; ++j) s[j] = fn(xx[j]); x += 1e-6f; for (int j=0; j < ls; ++j) yyy+=s[j]; } if (yyy == 2.32132323232f) niter--; return niter; } ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/49730] loop not vectorized if inside another loop 2011-07-13 10:43 [Bug tree-optimization/49730] New: loop not vectorized if inside another loop vincenzo.innocente at cern dot ch @ 2011-07-13 11:24 ` rguenth at gcc dot gnu.org 2011-07-14 6:35 ` irar at il dot ibm.com 2021-12-04 23:58 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: rguenth at gcc dot gnu.org @ 2011-07-13 11:24 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49730 Richard Guenther <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Keywords| |missed-optimization Last reconfirmed| |2011.07.13 11:23:16 CC| |irar at gcc dot gnu.org Ever Confirmed|0 |1 Severity|normal |enhancement --- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2011-07-13 11:23:16 UTC --- All inner loops are simply completely unrolled which eliminates the s array. Then we end up with a loop with two reductions which cannot be vectorized right now. ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/49730] loop not vectorized if inside another loop 2011-07-13 10:43 [Bug tree-optimization/49730] New: loop not vectorized if inside another loop vincenzo.innocente at cern dot ch 2011-07-13 11:24 ` [Bug tree-optimization/49730] " rguenth at gcc dot gnu.org @ 2011-07-14 6:35 ` irar at il dot ibm.com 2021-12-04 23:58 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: irar at il dot ibm.com @ 2011-07-14 6:35 UTC (permalink / raw) To: gcc-bugs http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49730 Ira Rosen <irar at il dot ibm.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |irar at il dot ibm.com --- Comment #2 from Ira Rosen <irar at il dot ibm.com> 2011-07-14 06:35:39 UTC --- There is no limitation on the number of reductions in vectorization. The problem here is a non-empty latch block. There are several existing PRs for similar problems: pr 33447, pr 28643. Ira ^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/49730] loop not vectorized if inside another loop 2011-07-13 10:43 [Bug tree-optimization/49730] New: loop not vectorized if inside another loop vincenzo.innocente at cern dot ch 2011-07-13 11:24 ` [Bug tree-optimization/49730] " rguenth at gcc dot gnu.org 2011-07-14 6:35 ` irar at il dot ibm.com @ 2021-12-04 23:58 ` pinskia at gcc dot gnu.org 2 siblings, 0 replies; 4+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-12-04 23:58 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=49730 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|--- |8.0 Resolution|--- |FIXED Known to work| |8.1.0, 9.1.0 Status|NEW |RESOLVED --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Fixed in GCC 8. ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-12-04 23:58 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2011-07-13 10:43 [Bug tree-optimization/49730] New: loop not vectorized if inside another loop vincenzo.innocente at cern dot ch 2011-07-13 11:24 ` [Bug tree-optimization/49730] " rguenth at gcc dot gnu.org 2011-07-14 6:35 ` irar at il dot ibm.com 2021-12-04 23:58 ` pinskia at gcc dot gnu.org
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