[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From pthaugen at us dot ibm dot com 2005-06-02 18:46 --- Does this need to be reopened? I see the following for mainline. -m32: .L4: slwi %r9,%r11,1 #, tmp130, i addi %r11,%r11,1 # i, i, sthx %r0,%r9,%r10#* q.1, tmp132 bdnz .L4 # -m64: .L4: sthx %r0,%r11,%r10 #* ivtmp.11, tmp132 addi %r10,%r10,2 # ivtmp.11, ivtmp.11, bdnz .L4 # Both can be improved to use a non-indexed store and increment of that base reg, similar to what Zdenek said he saw in comment #9. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
-- What|Removed |Added Target Milestone|--- |4.0.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From rakdver at gcc dot gnu dot org 2004-11-15 00:20 --- Fixed. -- What|Removed |Added Status|ASSIGNED|RESOLVED Resolution||FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From cvs-commit at gcc dot gnu dot org 2004-11-15 00:18 --- Subject: Bug 18431 CVSROOT:/cvs/gcc Module name:gcc Changes by: [EMAIL PROTECTED] 2004-11-15 00:18:37 Modified files: gcc: ChangeLog fold-const.c tree-ssa-loop-niter.c tree.c tree.h gcc/testsuite : ChangeLog Added files: gcc/testsuite/gcc.c-torture/execute: 20041114-1.c Log message: PR tree-optimization/18431 * fold-const.c (associate_trees): Do not produce x + 0. (fold_widened_comparison, fold_sign_changed_comparison): New functions. (fold): Use them. * tree-ssa-loop-niter.c (upper_bound_in_type, lower_bound_in_type): Moved ... * tree.c (upper_bound_in_type, lower_bound_in_type): Here. * tree.h (upper_bound_in_type, lower_bound_in_type): Declare. * testsuite/gcc.c-torture/execute/20041114-1.c: New test. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.6340&r2=2.6341 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/fold-const.c.diff?cvsroot=gcc&r1=1.473&r2=1.474 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-loop-niter.c.diff?cvsroot=gcc&r1=2.15&r2=2.16 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree.c.diff?cvsroot=gcc&r1=1.447&r2=1.448 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree.h.diff?cvsroot=gcc&r1=1.654&r2=1.655 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.4602&r2=1.4603 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/20041114-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1 -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From cvs-commit at gcc dot gnu dot org 2004-11-14 18:04 --- Subject: Bug 18431 CVSROOT:/cvs/gcc Module name:gcc Changes by: [EMAIL PROTECTED] 2004-11-14 18:04:26 Modified files: gcc: ChangeLog tree-flow.h tree-ssa-loop-im.c tree-ssa.c Log message: PR tree-optimization/18431 * tree-flow.h (stmt_references_memory_p): Declare. * tree-ssa-loop-im.c (stmt_cost): Use stmt_references_memory_p. * tree-ssa.c (stmt_references_memory_p): New function. Patches: http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.6332&r2=2.6333 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-flow.h.diff?cvsroot=gcc&r1=2.62&r2=2.63 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa-loop-im.c.diff?cvsroot=gcc&r1=2.21&r2=2.22 http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/tree-ssa.c.diff?cvsroot=gcc&r1=2.57&r2=2.58 -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-12 15:33 --- The local patch which I had in which caused this was a not so correct for PR 18293 (which we remove an extra copy RTL as we expand it so it looks like the cost analysis is doing something wrong which is why we don't do the IV-OPT when at the RTL either). -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From rakdver at atrey dot karlin dot mff dot cuni dot cz 2004-11-12 15:10 --- Subject: Re: Code for arrays and pointers are not the same > powerpc-darwin > > just -O3 > > hmm, must be a local modification which changes it. maybe you are checking 64 bit? That still looks terrible. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-12 14:53 --- (In reply to comment #8) > > is_gimple_addressable -> is_gimple_id -> is_gimple_variable -> SSA_NAME. > > So the correct patch would be I did post that patch also before it was rejected as I did not look into the aliasing problem we had. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-12 14:52 --- powerpc-darwin just -O3 hmm, must be a local modification which changes it. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From rakdver at atrey dot karlin dot mff dot cuni
dot cz 2004-11-12 14:48 ---
Subject: Re: Code for arrays and pointers are not the same
> huh a compiler built with that patch gives:
> L4:
> slwi r2,r9,1
> addi r9,r9,1
> sthx r0,r2,r11
> bdnz L4
>
> Also pulling the load manually out loop also produce the same asm as I just
> produced:
> unsigned short *q;
> #define NOSB 10
> int last;
> void h1()
> {
> int i;
> unsigned short *q1 = q;
> for (i=0;i{
> q1[i] = 0;
>}
> }
not for me:
.L4:
sth 0,0(9)
addi 9,9,2
bdnz .L4
what architecture/flags are you using?
Zdenek
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From rakdver at atrey dot karlin dot mff dot cuni dot cz 2004-11-12 14:46 --- Subject: Re: Code for arrays and pointers are not the same > > Patch here which should fix not pulling the load of q out of the loop: > > http://gcc.gnu.org/ml/gcc-patches/2004-11/msg00957.html > > > > Then the only thing left is for IV-OPTS to be fixed. > > no -- once this is done, ivopts work just fine, producing the same code > as for array access. btw. the patch above might be wrong -- I think ssa names also pass the is_gimple_addressable test: is_gimple_addressable -> is_gimple_id -> is_gimple_variable -> SSA_NAME. So the correct patch would be Index: tree-ssa-loop-im.c === RCS file: /cvs/gcc/gcc/gcc/tree-ssa-loop-im.c,v retrieving revision 2.21 diff -c -3 -p -r2.21 tree-ssa-loop-im.c *** tree-ssa-loop-im.c 8 Nov 2004 13:54:39 - 2.21 --- tree-ssa-loop-im.c 12 Nov 2004 11:29:40 - *** stmt_cost (tree stmt) *** 367,373 /* Hoisting memory references out should almost surely be a win. */ if (!is_gimple_variable (lhs)) cost += 20; ! if (is_gimple_addressable (rhs) && !is_gimple_variable (rhs)) cost += 20; switch (TREE_CODE (rhs)) --- 367,373 /* Hoisting memory references out should almost surely be a win. */ if (!is_gimple_variable (lhs)) cost += 20; ! if (is_gimple_addressable (rhs) && TREE_CODE (rhs) != SSA_NAME) cost += 20; switch (TREE_CODE (rhs)) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-12
14:44 ---
huh a compiler built with that patch gives:
L4:
slwi r2,r9,1
addi r9,r9,1
sthx r0,r2,r11
bdnz L4
Also pulling the load manually out loop also produce the same asm as I just
produced:
unsigned short *q;
#define NOSB 10
int last;
void h1()
{
int i;
unsigned short *q1 = q;
for (i=0;ihttp://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From rakdver at atrey dot karlin dot mff dot cuni dot cz 2004-11-12 14:42 --- Subject: Re: Code for arrays and pointers are not the same > Patch here which should fix not pulling the load of q out of the loop: > http://gcc.gnu.org/ml/gcc-patches/2004-11/msg00957.html > > Then the only thing left is for IV-OPTS to be fixed. no -- once this is done, ivopts work just fine, producing the same code as for array access. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-12 14:38 --- Patch here which should fix not pulling the load of q out of the loop: http://gcc.gnu.org/ml/gcc-patches/2004-11/msg00957.html Then the only thing left is for IV-OPTS to be fixed. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From rakdver at gcc dot gnu dot org 2004-11-12 11:24 --- The problem seems to be that licm does not move load of q from the loop. Ivopts then do not recognize q + 2*i as induction variable, and thus they are optimizing it not like an address of memory reference, but just like a computation of 2*i, for which it obviously does not make sense to perform strength reduction. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
-- What|Removed |Added AssignedTo|unassigned at gcc dot gnu |rakdver at gcc dot gnu dot |dot org |org Status|NEW |ASSIGNED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From nathan at gcc dot gnu dot org 2004-11-12 09:32 --- It is not what I thought it was. The array case is optimized at the tree level, the pointer case is optimized at the rtl level. -- What|Removed |Added AssignedTo|nathan at gcc dot gnu dot |unassigned at gcc dot gnu |org |dot org Status|ASSIGNED|NEW http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-11
20:39 ---
Rewritting the code this way, shows how we ahould be optimizing the code:
void h()
{
int i;
unsigned short *q1 = q;
for (i=0;ihttp://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
-- What|Removed |Added AssignedTo|unassigned at gcc dot gnu |nathan at gcc dot gnu dot |dot org |org Status|UNCONFIRMED |ASSIGNED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
--- Additional Comments From pinskia at gcc dot gnu dot org 2004-11-11 18:15 --- Note with powerpc64 we get much worse than array case which stays the same: L4: sldi r2,r9,1 addi r0,r9,1 sthx r10,r2,r11 extsw r9,r0 bdnz L4 -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
-- What|Removed |Added CC||rakdver at gcc dot gnu dot ||org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
[Bug tree-optimization/18431] Code for arrays and pointers are not the same
-- What|Removed |Added GCC target triplet||powerpc-darwin http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18431
