https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87917
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |sebpop at gmail dot com
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
I get:
during GIMPLE pass: ldist
pr34635.c: In function ‘foo’:
pr34635.c:4:6: internal compiler error: tree check: expected integer_cst, have
polynomial_chrec in int_cst_value, at tree.c:11188
4 | void foo(int x[])
| ^~~
0x1397ffc tree_check_failed(tree_node const*, char const*, int, char const*,
...)
/tmp/trunk/gcc/tree.c:9371
0x83e3a7 tree_int_cst_elt_check(tree_node const*, int, char const*, int, char
const*)
/tmp/trunk/gcc/tree.h:3307
0x13a0e5b int_cst_value(tree_node const*)
/tmp/trunk/gcc/tree.c:11188
#11 0x00000000010cf399 in get_data_dependence (rdg=0x2816ba0, a=0x2817830,
b=0x28170c0) at /tmp/trunk/gcc/tree-loop-distribution.c:1188
1188 compute_affine_dependence (ddr, loop_nest[0]);
(gdb) l
1183 ent.b = b;
1184 slot = ddrs_table->find_slot (&ent, INSERT);
1185 if (*slot == NULL)
1186 {
1187 ddr = initialize_data_dependence_relation (a, b, loop_nest);
1188 compute_affine_dependence (ddr, loop_nest[0]);
1189 *slot = ddr;
1190 }
(gdb) p debug_data_reference (a)
#(Data Ref:
# bb: 3
# stmt: _8 = *_4;
# ref: *_4;
# base_object: *x_22(D);
# Access function 0: {0B, +, {0, +, 4}_1}_2
#)
$6 = void
(gdb) p debug_data_reference (b)
#(Data Ref:
# bb: 3
# stmt: *_7 = _8;
# ref: *_7;
# base_object: *x_22(D);
# Access function 0: {0B, +, 4}_1
#)
so we have an "invariant" access and a variant one.
I think
else if (evolution_function_is_affine_multivariate_p (chrec_a,
loop_nest->num)
&& !chrec_contains_symbols (chrec_a)
&& evolution_function_is_affine_multivariate_p (chrec_b,
loop_nest->num)
&& !chrec_contains_symbols (chrec_b))
{
/* testsuite/.../ssa-chrec-35.c
{0, +, 1}_2 vs. {0, +, 1}_3
the overlapping elements are respectively located at iterations:
{0, +, 1}_x and {0, +, 1}_x,
in other words, we have the equality:
{0, +, 1}_2 ({0, +, 1}_x) = {0, +, 1}_3 ({0, +, 1}_x)
Other examples:
{{0, +, 1}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y) =
{0, +, 1}_1 ({{0, +, 1}_x, +, 2}_y)
{{0, +, 2}_1, +, 3}_2 ({0, +, 1}_y, {0, +, 1}_x) =
{{0, +, 3}_1, +, 2}_2 ({0, +, 1}_x, {0, +, 1}_y)
*/
analyze_subscript_affine_affine (chrec_a, chrec_b,
overlaps_a, overlaps_b, last_conflicts);
is not properly guarded. evolution_function_is_affine_multivariate_p
lets this through via
bool
evolution_function_is_affine_multivariate_p (const_tree chrec, int loopnum)
{
if (chrec == NULL_TREE)
return false;
switch (TREE_CODE (chrec))
{
case POLYNOMIAL_CHREC:
if (evolution_function_is_invariant_rec_p (CHREC_LEFT (chrec), loopnum))
{
if (evolution_function_is_invariant_rec_p (CHREC_RIGHT (chrec),
loopnum))
return true;
else
{
if (TREE_CODE (CHREC_RIGHT (chrec)) == POLYNOMIAL_CHREC
&& CHREC_VARIABLE (CHREC_RIGHT (chrec))
!= CHREC_VARIABLE (chrec)
&& evolution_function_is_affine_multivariate_p
(CHREC_RIGHT (chrec), loopnum))
but as we are interested in loopnum == 1 for {0, +, {0, +, 4}_1}_2
we have to exclude the case where CHREC_RIGHT variates in it.
Whatever exactly a affine multivariate is...
Sebastian - can you say if
evolution_function_is_affine_multivariate_p ({0, +, {0, +, 4}_1}_2, 1)
should really return true?
