https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86232
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Known to work| |8.1.1
Keywords| |ice-on-valid-code
Last reconfirmed| |2018-06-21
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot
gnu.org
Ever confirmed|0 |1
Summary|ICE in record_estimate, at |[9 Regression] ICE in
|tree-ssa-loop-niter.c:3258 |record_estimate, at
| |tree-ssa-loop-niter.c:3258
Target Milestone|--- |9.0
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
3258 gcc_checking_assert (i_bound == wi::to_widest (bound));
(gdb) l
3253 /* If the I_BOUND is just an estimate of BOUND, it rarely is close to
the
3254 real number of iterations. */
3255 if (TREE_CODE (bound) != INTEGER_CST)
3256 realistic = false;
3257 else
3258 gcc_checking_assert (i_bound == wi::to_widest (bound));
3259
3260 /* If we have a guaranteed upper bound, record it in the appropriate
3261 list, unless this is an !is_exit bound (i.e. undefined behavior in
3262 at_stmt) in a loop with known constant number of iterations. */
(gdb) p i_bound
$1 = (const widest_int &) @0x7fffffffd738: {<fixed_wide_int_storage<192>> = {
val = {32, 140737330801152, 140737330854096, 140737329677800}, len = 1},
static is_sign_extended = <optimized out>}
(gdb) p bound
$2 = <integer_cst 0x7ffff69cb8d0>
(gdb) p debug_generic_expr (bound)
1
$3 = void
that's because we compute niter to constant 1 but specify a max of 32.
Fix:
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index 936591502d0..f5ffc0f19ad 100644
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -2575,9 +2575,6 @@ number_of_iterations_popcount (loop_p loop, edge exit,
return false;
/* Update NITER params accordingly */
- max = TYPE_PRECISION (TREE_TYPE (src));
- if (adjust)
- max = max - 1;
tree utype = unsigned_type_for (TREE_TYPE (src));
src = fold_convert (utype, src);
tree call = fold_convert (utype, build_call_expr (fn, 1, src));
@@ -2588,6 +2585,15 @@ number_of_iterations_popcount (loop_p loop, edge exit,
else
iter = call;
+ if (TREE_CODE (call) == INTEGER_CST)
+ max = tree_to_uhwi (call);
+ else
+ {
+ max = TYPE_PRECISION (TREE_TYPE (src));
+ if (adjust)
+ max = max - 1;
+ }
+
niter->niter = iter;
niter->assumptions = boolean_true_node;
if (adjust)
