[Bug tree-optimization/92039] [10 Regression] Spurious -Warray-bounds warnings building 32-bit glibc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039 Jeffrey A. Law changed: What|Removed |Added Status|UNCONFIRMED |NEW Last reconfirmed||2019-10-09 CC||law at redhat dot com Ever confirmed|0 |1 --- Comment #1 from Jeffrey A. Law --- My tester tripped this as well. Confirming.
[Bug tree-optimization/92039] [10 Regression] Spurious -Warray-bounds warnings building 32-bit glibc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039 Richard Biener changed: What|Removed |Added Keywords||diagnostic Blocks||56456 Target Milestone|--- |10.0 --- Comment #2 from Richard Biener --- The rev in question changed heuristics as to when unrolling is applied so the issue is latent (and probably has a duplicate). Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56456 [Bug 56456] [meta-bug] bogus/missing -Warray-bounds
[Bug tree-optimization/92039] [10 Regression] Spurious -Warray-bounds warnings building 32-bit glibc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039 Richard Biener changed: What|Removed |Added Keywords||needs-reduction --- Comment #3 from Richard Biener --- _1235 = numsize.165_444 - densize_607; _1236 = retval[_1235]; we compute _1235 to be in [-4,-1]. Directly after unrolling it was [../stdlib/strtod_l.c:1675:9] if (empty_1004 <= i_1232) goto ; [80.00%] [local count: 284953]: [../stdlib/strtod_l.c:1676:25] _1235 = i_1232 - empty_1004; [../stdlib/strtod_l.c:1676:22] _1236 = [../stdlib/strtod_l.c:1676:22] retval[_1235]; and forwprop "mangles" it to the above because empty_1004 = densize_425 - numsize.165_444; and i_1232 is zero here. That means the last unrolled iteration isn't reachable. Note we do complete peeling here (keeping the exit checks). I had the impression I disabled this for early unrolling... hmm, I kept it for UL_NO_GROWTH, see PR83202.
[Bug tree-optimization/92039] [10 Regression] Spurious -Warray-bounds warnings building 32-bit glibc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039 Richard Biener changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org
[Bug tree-optimization/92039] [10 Regression] Spurious -Warray-bounds warnings building 32-bit glibc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039
Martin Liška changed:
What|Removed |Added
Keywords|needs-reduction |
CC||marxin at gcc dot gnu.org
--- Comment #4 from Martin Liška ---
Just for the record a reduced test-case:
int a[3];
void fn1(long b) {
int i;
for (i = 3; i >= b; --i)
a[i] = a[i - b];
}
where does not need -m32:
$ gcc -Werror=array-bounds -O2 -c ice.i
ice.i: In function ‘fn1’:
ice.i:6:6: error: array subscript 3 is above array bounds of ‘int[3]’
[-Werror=array-bounds]
6 | a[i] = a[i - b];
| ~^~~
ice.i:1:5: note: while referencing ‘a’
1 | int a[3];
| ^
cc1: some warnings being treated as errors
$ gcc-9 -Werror=array-bounds -O2 -c ice.i
[Bug tree-optimization/92039] [10 Regression] Spurious -Warray-bounds warnings building 32-bit glibc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039
--- Comment #5 from rguenther at suse dot de ---
On Wed, 23 Oct 2019, marxin at gcc dot gnu.org wrote:
> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039
>
> Martin Liška changed:
>
>What|Removed |Added
>
>Keywords|needs-reduction |
> CC||marxin at gcc dot gnu.org
>
> --- Comment #4 from Martin Liška ---
> Just for the record a reduced test-case:
>
> int a[3];
>
> void fn1(long b) {
> int i;
> for (i = 3; i >= b; --i)
> a[i] = a[i - b];
> }
>
> where does not need -m32:
>
> $ gcc -Werror=array-bounds -O2 -c ice.i
> ice.i: In function ‘fn1’:
> ice.i:6:6: error: array subscript 3 is above array bounds of ‘int[3]’
> [-Werror=array-bounds]
> 6 | a[i] = a[i - b];
> | ~^~~
> ice.i:1:5: note: while referencing ‘a’
> 1 | int a[3];
> | ^
> cc1: some warnings being treated as errors
>
> $ gcc-9 -Werror=array-bounds -O2 -c ice.i
The testcase is probably misreduced since the very first iteration
will write to a[3] out of bounds so it only is valid if the loop
is not entered, thus if b < 3.
[Bug tree-optimization/92039] [10 Regression] Spurious -Warray-bounds warnings building 32-bit glibc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039 --- Comment #6 from Florian Weimer --- *** Bug 92337 has been marked as a duplicate of this bug. ***
[Bug tree-optimization/92039] [10 Regression] Spurious -Warray-bounds warnings building 32-bit glibc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039 --- Comment #8 from Richard Biener --- Author: rguenth Date: Fri Nov 15 09:09:16 2019 New Revision: 278281 URL: https://gcc.gnu.org/viewcvs?rev=278281&root=gcc&view=rev Log: 2019-11-15 Richard Biener PR tree-optimization/92039 PR tree-optimization/91975 * tree-ssa-loop-ivcanon.c (constant_after_peeling): Revert previous change, treat invariants consistently as non-constant. (tree_estimate_loop_size): Ternary ops with just the first op constant are not optimized away. * gcc.dg/tree-ssa/cunroll-2.c: Revert to state previous to unroller adjustment. * g++.dg/tree-ssa/ivopts-3.C: Likewise. Modified: trunk/gcc/ChangeLog trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/g++.dg/tree-ssa/ivopts-3.C trunk/gcc/testsuite/gcc.dg/tree-ssa/cunroll-2.c trunk/gcc/tree-ssa-loop-ivcanon.c
[Bug tree-optimization/92039] [10 Regression] Spurious -Warray-bounds warnings building 32-bit glibc
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92039 Richard Biener changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #7 from Richard Biener --- Fixed.
