[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347 since r14-6420
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 Jakub Jelinek changed: What|Removed |Added Status|ASSIGNED|RESOLVED Resolution|--- |FIXED --- Comment #16 from Jakub Jelinek --- Fixed.
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347 since r14-6420
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228
--- Comment #15 from GCC Commits ---
The master branch has been updated by Jakub Jelinek :
https://gcc.gnu.org/g:8c0dd8a6ff85d6e7b38957f2da400f5cfa8fef6b
commit r14-7002-g8c0dd8a6ff85d6e7b38957f2da400f5cfa8fef6b
Author: Jakub Jelinek
Date: Mon Jan 8 13:59:15 2024 +0100
gimplify: Fix ICE in recalculate_side_effects [PR113228]
The following testcase ICEs during regimplificatgion since the addition of
(convert (eqne zero_one_valued_p@0 INTEGER_CST@1))
simplification. That simplification is novel in the sense that in
gimplify_expr it can turn an expression (comparison in particular) into
a SSA_NAME. Normally when gimplify_expr sees originally a SSA_NAME, it
does
case SSA_NAME:
/* Allow callbacks into the gimplifier during optimization. */
ret = GS_ALL_DONE;
break;
and doesn't try to recalculate side effects because of that, but in this
case gimplify_expr normally enters the:
default:
switch (TREE_CODE_CLASS (TREE_CODE (*expr_p)))
{
case tcc_comparison:
then does
*expr_p = gimple_boolify (*expr_p);
and then
*expr_p = fold_convert_loc (input_location,
org_type, *expr_p);
with this new match.pd simplification turns that tcc_comparison class
into SSA_NAME. Unlike the outer SSA_NAME handling though, this falls
through into
recalculate_side_effects (*expr_p);
dont_recalculate:
break;
but unfortunately recalculate_side_effects doesn't handle SSA_NAME and ICEs
on it.
SSA_NAMEs don't ever have TREE_SIDE_EFFECTS set on those, so the following
patch fixes it by handling it similarly to the tcc_constant case.
2024-01-08 Jakub Jelinek
PR tree-optimization/113228
* gimplify.cc (recalculate_side_effects): Do nothing for SSA_NAMEs.
* gcc.c-torture/compile/pr113228.c: New test.
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347 since r14-6420
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 --- Comment #14 from Andrew Pinski --- (In reply to Jakub Jelinek from comment #12) > The reason why late gimplification/regimplification generally works fine > with SSA_NAMEs is that the > case SSA_NAME: > /* Allow callbacks into the gimplifier during optimization. */ > ret = GS_ALL_DONE; > break; > case doesn't fall through into the recalculation. It is just this new > match.pd folding which can turn a tcc_comparison *expr_p (which is what > generally wants to recalculate side-effects) into SSA_NAME (which isn't > handled there). Thanks for looking into this issue further and handling it.
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347 since r14-6420
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 Jakub Jelinek changed: What|Removed |Added Status|NEW |ASSIGNED Assignee|unassigned at gcc dot gnu.org |jakub at gcc dot gnu.org --- Comment #13 from Jakub Jelinek --- Created attachment 56991 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56991&action=edit gcc14-pr113228.patch So I'd just go with a simple patch to recalculate_side_effects. Changing the case SSA_NAME: in gimplify_expr obviously isn't needed, that works fine as is.
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347 since r14-6420
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 --- Comment #12 from Jakub Jelinek --- The reason why late gimplification/regimplification generally works fine with SSA_NAMEs is that the case SSA_NAME: /* Allow callbacks into the gimplifier during optimization. */ ret = GS_ALL_DONE; break; case doesn't fall through into the recalculation. It is just this new match.pd folding which can turn a tcc_comparison *expr_p (which is what generally wants to recalculate side-effects) into SSA_NAME (which isn't handled there).
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347 since r14-6420
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 Jakub Jelinek changed: What|Removed |Added Priority|P3 |P1 Summary|[14 Regression] ICE:|[14 Regression] ICE: |recalculate_side_effects, |recalculate_side_effects, |at gimplify.cc:3347 |at gimplify.cc:3347 since ||r14-6420 CC||jakub at gcc dot gnu.org --- Comment #11 from Jakub Jelinek --- Confirmed this started with r14-6420-g85c5efcffed19ca6160eeecc2d4faebd9fee63aa Reproduceable also on x86_64-linux with -O3.
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 --- Comment #10 from Patrick O'Neill --- (In reply to Andrew Pinski from comment #9) > Oh ok, I was deciding if I should look further into this or let someone else > handle it. Since it is from a fuzzer, I am just going to say I don't have > time to look into this latent bug even though I exposed it :). Makes sense, I'll start adding a little blurb to future testcases that come from the fuzzer so people can prioritize accordingly.
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 --- Comment #9 from Andrew Pinski --- (In reply to Patrick O'Neill from comment #8) > (In reply to Andrew Pinski from comment #7) > > This seems like a reduced testcase, where is the original testcase from? Or > > is it an automated code generator? > > This was found with the fuzzer we're using to try to nail down some spec > fails in risc-v vector [1]. We've had some success with this approach. Oh ok, I was deciding if I should look further into this or let someone else handle it. Since it is from a fuzzer, I am just going to say I don't have time to look into this latent bug even though I exposed it :).
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 --- Comment #8 from Patrick O'Neill --- (In reply to Andrew Pinski from comment #7) > This seems like a reduced testcase, where is the original testcase from? Or > is it an automated code generator? This was found with the fuzzer we're using to try to nail down some spec fails in risc-v vector [1]. We've had some success with this approach. I can share the unreduced testcase if that's interesting to you? [1]: Csmith used w/ scripts to compare risc-v qemu with native build/runs: https://github.com/patrick-rivos/gcc-fuzz-ci
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 --- Comment #7 from Andrew Pinski --- This seems like a reduced testcase, where is the original testcase from? Or is it an automated code generator?
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228
--- Comment #6 from Andrew Pinski ---
What match is doing is correct, what reassoc is doing looks to be ok, but the
gimplifier just falls over on `SSA_NAME != 0`.
This fixes the ICE but I don't understand how the gimplifier was handling
SSA_NAME before if it ever was, the code mentioned here has not changed since
the tuples was merged in:
```
diff --git a/gcc/gimplify.cc b/gcc/gimplify.cc
index 15b540646c2..0cbe159b383 100644
--- a/gcc/gimplify.cc
+++ b/gcc/gimplify.cc
@@ -3304,6 +3304,9 @@ recalculate_side_effects (tree t)
int len = TREE_OPERAND_LENGTH (t);
int i;
+ if (code == SSA_NAME)
+return;
+
switch (TREE_CODE_CLASS (code))
{
case tcc_expression:
@@ -18253,7 +18256,7 @@ gimplify_expr (tree *expr_p, gimple_seq *pre_p,
gimple_seq *post_p,
case SSA_NAME:
/* Allow callbacks into the gimplifier during optimization. */
ret = GS_ALL_DONE;
- break;
+ goto dont_recalculate;
case OMP_PARALLEL:
gimplify_omp_parallel (expr_p, pre_p);
```
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 --- Comment #5 from Andrew Pinski --- ``` #6 0x00d4594f in force_gimple_operand_gsi (gsi=0x7fffd3c0, expr=0x779fe6e0, simple_p=true, var=0x0, before=true, m=GSI_SAME_STMT) at ../../gcc/gimplify-me.cc:141 141 return force_gimple_operand_gsi_1 (gsi, expr, (gdb) p expr $1 = (tree) 0x779fe6e0 (gdb) p debug_tree(expr) unit-size align:8 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type 0x77822b28 precision:1 min max > arg:0 unit-size align:32 warn_if_not_align:0 symtab:0 alias-set 1 canonical-type 0x778225e8 precision:32 min max pointer_to_this > visited var def_stmt k$0_17 = PHI <_23(4), 0(3)> version:17 ptr-info 0x779ed390> arg:1 constant 0> t.c:15:21 start: t.c:15:16 finish: t.c:15:24> $2 = void (gdb) p debug_generic_expr(expr) k$0_17 != 0 ``` Exactly what I had expected. and yes it is exposed by that ...
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228
--- Comment #4 from Andrew Pinski ---
(In reply to Patrick O'Neill from comment #1)
> int k[3];
It would better if we didn't depend on an uninitialized variable (I have a
patch against reassoc to not handle uninitialized/undef names) and initializing
k as:
```
int k[3]={0,0,0};
```
Still shows the issue ...
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 --- Comment #3 from Andrew Pinski --- (gdb) p debug_tree(*expr_p) unit-size align:32 warn_if_not_align:0 symtab:0 alias-set 2 canonical-type 0x7741c5e8 precision:32 min max pointer_to_this > visited var def_stmt k$0_17 = PHI <_24(4), k$0_28(D)(3)> version:17 ptr-info 0x77343cc0>
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 Andrew Pinski changed: What|Removed |Added Ever confirmed|0 |1 Last reconfirmed||2024-01-04 Status|UNCONFIRMED |NEW --- Comment #2 from Andrew Pinski --- Confirmed, I am 99% sure this was exposed by r14-6420-g85c5efcffed19ca6160eeecc2d4faebd9fee63aa
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228 Andrew Pinski changed: What|Removed |Added Target Milestone|--- |14.0
[Bug middle-end/113228] [14 Regression] ICE: recalculate_side_effects, at gimplify.cc:3347
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113228
--- Comment #1 from Patrick O'Neill ---
Testcase:
int a;
long b;
signed c;
short d;
short i;
void f() {
int k[3];
int *l = &a;
d = 0;
for (; c; c--) {
i = 0;
for (; i <= 9; i++) {
b = 1;
for (; b <= 4; b++)
k[0] = k[0] == 0;
*l |= k[d];
}
}
}
