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* [Bug tree-optimization/36010] Loop interchange not performed [not found] <bug-36010-4@http.gcc.gnu.org/bugzilla/> @ 2021-12-25 11:15 ` pinskia at gcc dot gnu.org 2023-10-16 12:40 ` aagarwa at gcc dot gnu.org 2023-10-17 7:06 ` rguenth at gcc dot gnu.org 2 siblings, 0 replies; 7+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-12-25 11:15 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36010 --- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- This is still true, you need still need -fno-tree-pre -fno-tree-loop-im to get the loop to interchanged. -O2 -fno-tree-pre -fno-tree-loop-im -floop-interchange works while just -O2 -floop-interchange does not. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/36010] Loop interchange not performed [not found] <bug-36010-4@http.gcc.gnu.org/bugzilla/> 2021-12-25 11:15 ` [Bug tree-optimization/36010] Loop interchange not performed pinskia at gcc dot gnu.org @ 2023-10-16 12:40 ` aagarwa at gcc dot gnu.org 2023-10-17 7:06 ` rguenth at gcc dot gnu.org 2 siblings, 0 replies; 7+ messages in thread From: aagarwa at gcc dot gnu.org @ 2023-10-16 12:40 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36010 Ajit Kumar Agarwal <aagarwa at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |aagarwa at gcc dot gnu.org --- Comment #5 from Ajit Kumar Agarwal <aagarwa at gcc dot gnu.org> --- Use the following flags-fassociative-math -fno-signed-zeros -fno-trapping-math to make loop-interchange work. Following code in gcc/gimple-loop-interchange.cc @@ -514,8 +514,8 @@ loop_cand::analyze_iloop_reduction_var (tree var) if (! (associative_tree_code (code) || (code == MINUS_EXPR && use_p->use == gimple_assign_rhs1_ptr (ass))) || (FLOAT_TYPE_P (TREE_TYPE (var)) && ! flag_associative_math)) return false; } else Because of the flag_associative_math conditions at line no: 514 it returns false and loop interchange doesn't work. Using the above flags make flag_associative_math as true and loop interchange works. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/36010] Loop interchange not performed [not found] <bug-36010-4@http.gcc.gnu.org/bugzilla/> 2021-12-25 11:15 ` [Bug tree-optimization/36010] Loop interchange not performed pinskia at gcc dot gnu.org 2023-10-16 12:40 ` aagarwa at gcc dot gnu.org @ 2023-10-17 7:06 ` rguenth at gcc dot gnu.org 2 siblings, 0 replies; 7+ messages in thread From: rguenth at gcc dot gnu.org @ 2023-10-17 7:06 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=36010 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |rguenth at gcc dot gnu.org --- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> --- Hmm, the condition seems to be superfluous - we don't (in this case?) associate when moving the load/store back into the loop or when we perform the interchange? In fact the comment before the block suggests that. But yes, with -O2 -floop-interchange -ffast-math we now interchange the original testcase (and the case from bwaves). This was fixed with r8-5164-gfbdec14e80e939 which also introduced this check for associativity. ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/36010] New: Loop interchange not performed @ 2008-04-22 14:56 rguenth at gcc dot gnu dot org 2008-04-22 15:20 ` [Bug tree-optimization/36010] " rguenth at gcc dot gnu dot org ` (3 more replies) 0 siblings, 4 replies; 7+ messages in thread From: rguenth at gcc dot gnu dot org @ 2008-04-22 14:56 UTC (permalink / raw) To: gcc-bugs For the testcase double a[16][64], y[64], x[16]; void foo(void) { int i, j; for (j = 0; j < 64; ++j) for (i = 0; i < 16; ++i) y[j] = y[j] + a[i][j] * x[i]; } with -O2 -fno-tree-pre -fno-tree-loop-im -ftree-loop-linear loop interchange is performed but with PRE or lim moving the load (and the store) from/to y[j] out of the innermost loop the interchange is no longer performed because before = gcc_loopnest_to_lambda_loopnest (loop_nest, &oldivs, &invariants, &lambda_obstack); returns NULL. -- Summary: Loop interchange not performed Product: gcc Version: 4.4.0 Status: UNCONFIRMED Keywords: missed-optimization Severity: normal Priority: P3 Component: tree-optimization AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: rguenth at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36010 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/36010] Loop interchange not performed 2008-04-22 14:56 [Bug tree-optimization/36010] New: " rguenth at gcc dot gnu dot org @ 2008-04-22 15:20 ` rguenth at gcc dot gnu dot org 2008-04-22 15:23 ` rguenth at gcc dot gnu dot org ` (2 subsequent siblings) 3 siblings, 0 replies; 7+ messages in thread From: rguenth at gcc dot gnu dot org @ 2008-04-22 15:20 UTC (permalink / raw) To: gcc-bugs ------- Comment #1 from rguenth at gcc dot gnu dot org 2008-04-22 15:19 ------- perfect_nestify needs to be enhanced to handle this I guess. In fact we cannot distribute these loops but need to undo what PRE/lim do. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36010 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/36010] Loop interchange not performed 2008-04-22 14:56 [Bug tree-optimization/36010] New: " rguenth at gcc dot gnu dot org 2008-04-22 15:20 ` [Bug tree-optimization/36010] " rguenth at gcc dot gnu dot org @ 2008-04-22 15:23 ` rguenth at gcc dot gnu dot org 2008-05-05 5:21 ` pinskia at gcc dot gnu dot org 2008-12-28 6:36 ` pinskia at gcc dot gnu dot org 3 siblings, 0 replies; 7+ messages in thread From: rguenth at gcc dot gnu dot org @ 2008-04-22 15:23 UTC (permalink / raw) To: gcc-bugs ------- Comment #2 from rguenth at gcc dot gnu dot org 2008-04-22 15:22 ------- Bwaves from SPEC2006 has ... do l=1,nb y(l,i,j,k)=0.0d0 do m=1,nb y(l,i,j,k)=y(l,i,j,k)+ 1 a(l,m,i,j,k)*x(m,i,j,k)+ 2 axp(l,m,i,j,k)*x(m,ip1,j,k)+ 3 ayp(l,m,i,j,k)*x(m,i,jp1,k)+ 4 azp(l,m,i,j,k)*x(m,i,j,kp1)+ 5 axm(l,m,i,j,k)*x(m,im1,j,k)+ 6 aym(l,m,i,j,k)*x(m,i,jm1,k)+ 7 azm(l,m,i,j,k)*x(m,i,j,km1) enddo enddo which we don't distribute either (even with PRE/lim turned off). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36010 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/36010] Loop interchange not performed 2008-04-22 14:56 [Bug tree-optimization/36010] New: " rguenth at gcc dot gnu dot org 2008-04-22 15:20 ` [Bug tree-optimization/36010] " rguenth at gcc dot gnu dot org 2008-04-22 15:23 ` rguenth at gcc dot gnu dot org @ 2008-05-05 5:21 ` pinskia at gcc dot gnu dot org 2008-12-28 6:36 ` pinskia at gcc dot gnu dot org 3 siblings, 0 replies; 7+ messages in thread From: pinskia at gcc dot gnu dot org @ 2008-05-05 5:21 UTC (permalink / raw) To: gcc-bugs -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |pinskia at gcc dot gnu dot | |org Severity|normal |enhancement http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36010 ^ permalink raw reply [flat|nested] 7+ messages in thread
* [Bug tree-optimization/36010] Loop interchange not performed 2008-04-22 14:56 [Bug tree-optimization/36010] New: " rguenth at gcc dot gnu dot org ` (2 preceding siblings ...) 2008-05-05 5:21 ` pinskia at gcc dot gnu dot org @ 2008-12-28 6:36 ` pinskia at gcc dot gnu dot org 3 siblings, 0 replies; 7+ messages in thread From: pinskia at gcc dot gnu dot org @ 2008-12-28 6:36 UTC (permalink / raw) To: gcc-bugs ------- Comment #3 from pinskia at gcc dot gnu dot org 2008-12-28 06:33 ------- Confirmed. -- pinskia at gcc dot gnu dot org changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Ever Confirmed|0 |1 Last reconfirmed|0000-00-00 00:00:00 |2008-12-28 06:33:38 date| | http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36010 ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2023-10-17 7:06 UTC | newest] Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <bug-36010-4@http.gcc.gnu.org/bugzilla/> 2021-12-25 11:15 ` [Bug tree-optimization/36010] Loop interchange not performed pinskia at gcc dot gnu.org 2023-10-16 12:40 ` aagarwa at gcc dot gnu.org 2023-10-17 7:06 ` rguenth at gcc dot gnu.org 2008-04-22 14:56 [Bug tree-optimization/36010] New: " rguenth at gcc dot gnu dot org 2008-04-22 15:20 ` [Bug tree-optimization/36010] " rguenth at gcc dot gnu dot org 2008-04-22 15:23 ` rguenth at gcc dot gnu dot org 2008-05-05 5:21 ` pinskia at gcc dot gnu dot org 2008-12-28 6:36 ` pinskia at gcc dot gnu dot org
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