https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84132
Uroš Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2018-01-30
Ever confirmed|0 |1
--- Comment #1 from Uroš Bizjak <ubizjak at gmail dot com> ---
Confirmed, gdb shows divide by zero on x86_64:
Program received signal SIGFPE, Arithmetic exception.
0x0000000001e5396f in gcd_of_steps_may_divide_p (chrec=0x7fffef991420,
cst=0x7fffef985a98) at /home/uros/gcc-svn/trunk/gcc/tree-data-ref.c:3938
3938 return val % cd == 0;
(gdb) list
3933 return true;
3934 cd = gcd (cd, tree_to_shwi (step));
3935 chrec = CHREC_LEFT (chrec);
3936 }
3937
3938 return val % cd == 0;
3939 }
3940
3941 /* Analyze a MIV (Multiple Index Variable) subscript with respect to
3942 LOOP_NEST. *OVERLAPS_A and *OVERLAPS_B are initialized to the
(gdb) p val
$1 = -1
(gdb) p cd
$2 = 0
(gdb) bt
#0 0x0000000001e5396f in gcd_of_steps_may_divide_p (chrec=0x7fffef991420,
cst=0x7fffef985a98) at /home/uros/gcc-svn/trunk/gcc/tree-data-ref.c:3938
#1 0x0000000001e53b69 in analyze_miv_subscript (chrec_a=0x7fffef991420,
chrec_b=0x7fffef991560, overlaps_a=0x7fffffffd488, overlaps_b=0x7fffffffd480,
last_conflicts=0x7fffffffd498,
loop_nest=0x7fffef97f110) at
/home/uros/gcc-svn/trunk/gcc/tree-data-ref.c:3982
#2 0x0000000001e540e5 in analyze_overlapping_iterations
(chrec_a=0x7fffef9905f0, chrec_b=0x7fffef990870,
overlap_iterations_a=0x7fffffffd488, overlap_iterations_b=0x7fffffffd480,
last_conflicts=0x7fffffffd498, loop_nest=0x7fffef97f110) at
/home/uros/gcc-svn/trunk/gcc/tree-data-ref.c:4120
#3 0x0000000001e55353 in subscript_dependence_tester_1 (ddr=0x2f26670,
a_index=0, b_index=1, loop_nest=0x7fffef97f110) at
/home/uros/gcc-svn/trunk/gcc/tree-data-ref.c:4656
#4 0x0000000001e55480 in subscript_dependence_tester (ddr=0x2f26670,
loop_nest=0x7fffef97f110) at /home/uros/gcc-svn/trunk/gcc/tree-data-ref.c:4706
#5 0x0000000001e556b0 in compute_affine_dependence (ddr=0x2f26670,
loop_nest=0x7fffef97f110) at /home/uros/gcc-svn/trunk/gcc/tree-data-ref.c:4765
#6 0x0000000001e55974 in compute_all_dependences (datarefs=...,
dependence_relations=0x7fffffffd670, loop_nest=..., compute_self_and_rr=true)
at /home/uros/gcc-svn/trunk/gcc/tree-data-ref.c:4832
#7 0x0000000001e567c0 in compute_data_dependences_for_loop
(loop=0x7fffef97f110, compute_self_and_read_read_dependences=true,
loop_nest=0x7fffffffd5c0, datarefs=0x7fffffffd678,
dependence_relations=0x7fffffffd670) at
/home/uros/gcc-svn/trunk/gcc/tree-data-ref.c:5231
#8 0x0000000001d32fb6 in tree_loop_unroll_and_jam () at
/home/uros/gcc-svn/trunk/gcc/gimple-loop-jam.c:425
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