[Bug tree-optimization/103690] [12 Regression] ICE: in build2, at tree.c:4985 with -g -O2 -fno-tree-dce -fno-tree-dse -fno-tree-fre --param=max-jump-thread-duplication-stmts=94 since r12-2591-g2e96b5f
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103690 Richard Biener changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #8 from Richard Biener --- Fixed.
[Bug tree-optimization/103690] [12 Regression] ICE: in build2, at tree.c:4985 with -g -O2 -fno-tree-dce -fno-tree-dse -fno-tree-fre --param=max-jump-thread-duplication-stmts=94 since r12-2591-g2e96b5f
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103690 --- Comment #7 from CVS Commits --- The master branch has been updated by Richard Biener : https://gcc.gnu.org/g:ebc853deb7cc0487de9ef6e891a007ba853d1933 commit r12-6208-gebc853deb7cc0487de9ef6e891a007ba853d1933 Author: Richard Biener Date: Tue Jan 4 11:59:35 2022 +0100 tree-optimization/103690 - not up-to-date SSA and PRE DCE This avoids running simple_dce_from_worklist on partially not up-to-date SSA form (in unreachable code regions) by scheduling CFG cleanup manually as is done anyway when tail-merging runs. 2022-01-04 Richard Biener PR tree-optimization/103690 * tree-pass.h (tail_merge_optimize): Adjust. * tree-ssa-tail-merge.c (tail_merge_optimize): Pass in whether to re-split critical edges, move CFG cleanup ... * tree-ssa-pre.c (pass_pre::execute): ... here, before simple_dce_from_worklist and delay freeing inserted_exprs from ... (fini_pre): .. here.
[Bug tree-optimization/103690] [12 Regression] ICE: in build2, at tree.c:4985 with -g -O2 -fno-tree-dce -fno-tree-dse -fno-tree-fre --param=max-jump-thread-duplication-stmts=94 since r12-2591-g2e96b5f
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103690 Richard Biener changed: What|Removed |Added Priority|P3 |P1 Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot gnu.org --- Comment #6 from Richard Biener --- Value numbering stmt = __trans_tmp_1_14 = _24 + 4; Setting value number of __trans_tmp_1_14 to __trans_tmp_1_22 (changed) what we do is avoiding useless work during elimination, not visiting if (0) guarded code - those regions will have not up-to-date SSA form. Block 14: BB5 found not executable the issue is that PRE does /* Because we don't follow exactly the standard PRE algorithm, and decide not to insert PHI nodes sometimes, and because value numbering of casts isn't perfect, we sometimes end up inserting dead code. This simple DCE-like pass removes any insertions we made that weren't actually used. */ simple_dce_from_worklist (inserted_exprs); which eventually runs into those uses for expressions we inserted into those unreachable blocks. The issue is long latent I think.
[Bug tree-optimization/103690] [12 Regression] ICE: in build2, at tree.c:4985 with -g -O2 -fno-tree-dce -fno-tree-dse -fno-tree-fre --param=max-jump-thread-duplication-stmts=94 since r12-2591-g2e96b5f
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103690 --- Comment #5 from Aldy Hernandez --- (In reply to Andrew Pinski from comment #2) > (gdb) p debug_gimple_stmt(stmt) > _67 = _14 + _66; > > > Before pre had: > intD.9 * __trans_tmp_1D.2946; > > # RANGE [1, 9223372036854775807] NONZERO 9223372036854775804 > _66 = (long unsigned intD.16) _17; > # PT = nonlocal escaped > # ALIGN = 4, MISALIGN = 0 > _67 = __trans_tmp_1_14 + _66; > > But after: > # RANGE [1, 9223372036854775807] NONZERO 9223372036854775804 > _66 = (long unsigned intD.16) _17; > # PT = nonlocal escaped > # ALIGN = 4, MISALIGN = 0 > _67 = _14 + _66; > > We already removed the definition of _14 too: > Removing dead stmt __trans_tmp_1_14 = _24 + 4; > > So it is the order of the removal which is causing issues. Why is PRE removing the DEF of _14 when there are still uses? [local count: 69834]: __count.1_62 = (long unsigned int) _11; __builtin_memmove (_14, _9, __count.1_62); _66 = (long unsigned int) _17; _67 = _14 + _66; ...
[Bug tree-optimization/103690] [12 Regression] ICE: in build2, at tree.c:4985 with -g -O2 -fno-tree-dce -fno-tree-dse -fno-tree-fre --param=max-jump-thread-duplication-stmts=94 since r12-2591-g2e96b5f
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103690
Alex Coplan changed:
What|Removed |Added
CC||acoplan at gcc dot gnu.org
--- Comment #4 from Alex Coplan ---
Here's a slightly cleaned up testcase which fails with the same options FWIW:
typedef int *int_ptr;
struct __normal_iterator {
int *_M_current;
__normal_iterator(const int_ptr &__i) : _M_current(__i) {}
void foo() { __normal_iterator(_M_current - 1); }
};
void deallocate(int *);
struct vector {
int *_M_start;
int *_M_finish;
__normal_iterator end() { return _M_finish; }
int back() {
__normal_iterator t = _M_finish;
t.foo();
}
void foo();
};
int *p1, *p2;
int last, result;
void vector::foo() {
for (int i; i;)
while (i) {
__normal_iterator t1 = end();
int *p3, *__old_start = _M_start, *__new_finish;
long __count = - __old_start;
if (__count > 0)
__builtin_memmove(, __old_start, __count);
p1 = + __count;
p2 = p1 + 1;
__count = _M_finish - t1._M_current;
if (__count)
__builtin_memmove(p2, t1._M_current, __count);
p3 = p2 + __count;
__new_finish = p3;
if (__old_start)
deallocate(__old_start);
_M_finish = __new_finish;
back();
}
}
also confirmed on aarch64-linux-gnu.
[Bug tree-optimization/103690] [12 Regression] ICE: in build2, at tree.c:4985 with -g -O2 -fno-tree-dce -fno-tree-dse -fno-tree-fre --param=max-jump-thread-duplication-stmts=94 since r12-2591-g2e96b5f
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103690 Martin Liška changed: What|Removed |Added CC||aldyh at gcc dot gnu.org, ||amacleod at redhat dot com, ||marxin at gcc dot gnu.org Summary|[12 Regression] ICE: in |[12 Regression] ICE: in |build2, at tree.c:4985 with |build2, at tree.c:4985 with |-g -O2 -fno-tree-dce|-g -O2 -fno-tree-dce |-fno-tree-dse -fno-tree-fre |-fno-tree-dse -fno-tree-fre |--param=max-jump-thread-dup |--param=max-jump-thread-dup |lication-stmts=94 |lication-stmts=94 since ||r12-2591-g2e96b5f14e402569 --- Comment #3 from Martin Liška --- Started with r12-2591-g2e96b5f14e402569.
