[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-06-09 16:32 --- This has now been fixed. -- What|Removed |Added Status|NEW |RESOLVED Resolution||FIXED Target Milestone|--- |4.1.0 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From rguenth at gcc dot gnu dot org 2005-05-18 21:51 --- Nice. Now it's really an aliasing problem only - and maybe bad timing for when we end up with such nice state. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
-- Bug 19626 depends on bug 17141, which changed state. Bug 17141 Summary: *a-b is not folded http://gcc.gnu.org/bugzilla/show_bug.cgi?id=17141 What|Old Value |New Value Status|ASSIGNED|RESOLVED Resolution||FIXED http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-05-17 17:35 --- We now get: dX.D.2296.D.2252.domain_m[0].D.2209.D.2200.D.2154.domain_m = 1; dX.D.2296.D.2252.domain_m[1].D.2209.D.2200.D.2154.domain_m = 0; k.D.2296.D.2252.domain_m[0].D.2209.D.2200.D.2154.domain_m = 0; k.D.2296.D.2252.domain_m[1].D.2209.D.2200.D.2154.domain_m = 1; return k.D.2296.D.2252.domain_m[0].D.2209.D.2200.D.2154.domain_m + dX.D.2296.D.2252.domain_m[0].D.2209.D.2200.D.2154.domain_m; -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-05-13 13:18 --- Most of the problem is PR 17141, the other problem comes into play with struct aliasing issues. -- What|Removed |Added BugsThisDependsOn||17141 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From rguenth at gcc dot gnu dot org 2005-04-07 10:30 --- Created an attachment (id=8554) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8554action=view) Revised testcase without confusing casts This changes the testcase to not cast int* to Loc1*, but use Loc1[2] as storage for Loc2 while retaining the initialization properties. It requires the testcase be compiled with tree-level loop-unrolling enabled, as the empty constructors/destructors for array members are created as loops by the C++ frontend. Other than that, struct aliasing (or just removing the casts) doesn't fix the aliasing problems - though struct aliasing doesn't handle array elements at the moment(?). -- What|Removed |Added Attachment #8062 is|0 |1 obsolete|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From dberlin at gcc dot gnu dot org 2005-04-07 12:48 --- Subject: Re: Aliasing says stores to local memory do alias Other than that, struct aliasing (or just removing the casts) doesn't fix the aliasing problems - though struct aliasing doesn't handle array elements at the moment(?). Correct, it does not. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de 2005-04-07 12:50 --- Subject: Re: Aliasing says stores to local memory do alias On 7 Apr 2005, dberlin at dberlin dot org wrote: --- Additional Comments From dberlin at gcc dot gnu dot org 2005-04-07 12:48 --- Subject: Re: Aliasing says stores to local memory do alias Other than that, struct aliasing (or just removing the casts) doesn't fix the aliasing problems - though struct aliasing doesn't handle array elements at the moment(?). Correct, it does not. Ok, at least the RTL optimizers figure out that these stack locals cannot alias. Hope we get this for the tree optimizers, too. Richard. -- Richard Guenther richard dot guenther at uni-tuebingen dot de WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/ -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From dberlin at gcc dot gnu dot org 2005-04-07 16:43 --- Subject: Re: Aliasing says stores to local memory do alias Other than that, struct aliasing (or just removing the casts) doesn't fix the aliasing problems - though struct aliasing doesn't handle array elements at the moment(?). Correct, it does not. Ok, at least the RTL optimizers figure out that these stack locals cannot alias. Hope we get this for the tree optimizers, too. It's already in my plans. It's just the implementation is a bit trickier than one would like :) -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-04-07 22:55 --- Confirmed. -- What|Removed |Added Status|UNCONFIRMED |NEW Ever Confirmed||1 Last reconfirmed|-00-00 00:00:00 |2005-04-07 22:55:38 date|| http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From rguenth at gcc dot gnu dot org 2005-02-10
13:18 ---
Actually, exchanging loc_test for
int loc_test(void)
{
const Loc2 k(0, 1);
return k[0].first();
}
shows the same problem:
bb 0:
D.2541 = (struct Loc1 *) k.D.2190.D.2155.domain_m.buffer;
# k_160 = V_MAY_DEF k_150;
*(D.2541-D.2101)-D.2064.domain_m = 0;
# k_63 = V_MAY_DEF k_160;
*((D.2541 + 4B)-D.2101)-D.2064.domain_m = 1;
D.2628 = (struct Loc1 *) k.D.2190.D.2155.domain_m.buffer;
return (D.2628-D.2101)-D.2064.domain_m;
One problem might be, that PRE does not recognize the redundant
(struct Loc1D.1872 *) kD.1965.D.2190.D.2155.domain_mD.2002.bufferD.2015
in
L0:;
currIndex_114 = 1;
D.2554_122 = (struct Loc1 *) k.D.2190.D.2155.domain_m.buffer;
n.6_123 = 0;
D.2556_124 = 0;
D.2557_125 = 0B;
D.2548_126 = D.2554_122;
this_130 = D.2548_126-D.2101;
dom_133 = this_130-D.2064.domain_m;
# k_160 = V_MAY_DEF k_150;
*dom_133 = 0;
D.2540_141 = 1;
L29:;
currIndex_79 = 2;
n.6_88 = 1;
D.2604_89 = 4;
D.2605_90 = 4B;
D.2596_91 = D.2554_122 + 4B;
this_95 = D.2596_91-D.2101;
dom_98 = this_95-D.2064.domain_m;
# k_63 = V_MAY_DEF k_160;
*dom_98 = 1;
D.2588_106 = 1;
D.2641_47 = (struct Loc1 *) k.D.2190.D.2155.domain_m.buffer;
this_55 = D.2641_47-D.2101;
# VUSE TMT.12_38;
# VUSE k_63;
d_57 = this_55-D.2064.domain_m;
return d_57;
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de 2005-01-26 08:47 --- Subject: Re: Aliasing says stores to local memory do alias D.2540 = (struct Loc1 *) dX.D.2210.D.2166.domain_m.buffer; That confuses the aliasing mechanism buffer is of type int* but you are casting it to Loc1 *. Telling it the truth by having an array of Loc1 instead doesn't help. I suppose you're talking about not decomposing Loc2 into two Loc1 as intermediate step? Well, yes, that's a design decision I cannot change. It looks superfluous for Loc, but makes sense for the more complex domain objects like Interval and Range (but that's a different story). But in principle a compiler could determine that the two objects cannot alias, even which this interwinded type structure? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From rguenth at tat dot physik dot uni-tuebingen dot de 2005-01-25 16:57 --- Created an attachment (id=8062) -- (http://gcc.gnu.org/bugzilla/attachment.cgi?id=8062action=view) testcase -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-01-25 17:15 --- If you had used the correct types in the first place instead of this crazy uninitialized pointer this works (almost): dX.D.2220.D.2170.domain_m.buffer[0].D.2098.D.2055.domain_m = 1; dX.D.2220.D.2170.domain_m.buffer[1].D.2098.D.2055.domain_m = 0; k.D.2220.D.2170.domain_m.buffer[0].D.2098.D.2055.domain_m = 0; k.D.2220.D.2170.domain_m.buffer[1].D.2098.D.2055.domain_m = 1; return k.D.2220.D.2170.domain_m.buffer[0].D.2098.D.2055.domain_m + dX.D.2220.D.2170.domain_m.buffer[0].D.2098.D.2055.domain_m; -- What|Removed |Added Severity|normal |enhancement Keywords||alias, missed-optimization, ||TREE Priority|P2 |P3 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
[Bug tree-optimization/19626] Aliasing says stores to local memory do alias
--- Additional Comments From pinskia at gcc dot gnu dot org 2005-01-25 17:20 --- D.2540 = (struct Loc1 *) dX.D.2210.D.2166.domain_m.buffer; That confuses the aliasing mechanism buffer is of type int* but you are casting it to Loc1 *. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19626
