* [PATCH] tree-optimization: [PR108684] ICE in verify_ssa due to simple_dce_from_worklist
@ 2023-02-08 19:13 Andrew Pinski
2023-02-09 8:06 ` Richard Biener
0 siblings, 1 reply; 3+ messages in thread
From: Andrew Pinski @ 2023-02-08 19:13 UTC (permalink / raw)
To: gcc-patches; +Cc: Andrew Pinski, Andrew Macleod
In simple_dce_from_worklist, we were removing an inline-asm which had a vdef
(due to clobbering memory) but not unlinking the statement's vdef.
This fixes that oversight. This was a latent bug exposed recently
by both VRP and removal of stores to static starting to use
simple_dce_from_worklist.
OK for trunk (and for GCC 12 after a week)?
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/108684
gcc/ChangeLog:
* tree-ssa-dce.cc (simple_dce_from_worklist):
Call unlink_stmt_vdef on the statement before
removing it.
gcc/testsuite/ChangeLog:
* gcc.c-torture/compile/dce-inline-asm-1.c: New test.
* gcc.c-torture/compile/dce-inline-asm-2.c: New test.
co-authored-by: Andrew Macleod <amacleod@redhat.com>
---
.../gcc.c-torture/compile/dce-inline-asm-1.c | 15 +++++++++++++++
.../gcc.c-torture/compile/dce-inline-asm-2.c | 16 ++++++++++++++++
gcc/tree-ssa-dce.cc | 1 +
3 files changed, 32 insertions(+)
create mode 100644 gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c
create mode 100644 gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c
diff --git a/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c
new file mode 100644
index 00000000000..a9f02e44bd7
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c
@@ -0,0 +1,15 @@
+/* PR tree-optimization/108684 */
+/* This used to ICE as when we remove the store to
+ `t`, we also would remove the inline-asm which
+ had a VDEF on it but we didn't update the
+ VUSE that was later on. */
+static int t;
+
+int f (int *a)
+{
+ int t1;
+ asm (" " : "=X" (t1) : : "memory");
+ t = t1;
+ return *a;
+}
+
diff --git a/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c
new file mode 100644
index 00000000000..a41b16e4bd0
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c
@@ -0,0 +1,16 @@
+/* PR tree-optimization/108684 */
+/* This used to ICE as when we removed the
+ __builtin_unreachable in VRP, as we
+ would also remove the branch and the
+ inline-asm. The inline-asm had a VDEF on it,
+ which we didn't update further along and
+ not have the VDEF on the return statement
+ updated. */
+
+int f (int a)
+{
+ asm (" " : "=X" (a) : : "memory");
+ if (a)
+ return 0;
+ __builtin_unreachable();
+}
diff --git a/gcc/tree-ssa-dce.cc b/gcc/tree-ssa-dce.cc
index b2fe9f4f55e..752785541e4 100644
--- a/gcc/tree-ssa-dce.cc
+++ b/gcc/tree-ssa-dce.cc
@@ -2140,6 +2140,7 @@ simple_dce_from_worklist (bitmap worklist)
remove_phi_node (&gsi, true);
else
{
+ unlink_stmt_vdef (t);
gsi_remove (&gsi, true);
release_defs (t);
}
--
2.31.1
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] tree-optimization: [PR108684] ICE in verify_ssa due to simple_dce_from_worklist
2023-02-08 19:13 [PATCH] tree-optimization: [PR108684] ICE in verify_ssa due to simple_dce_from_worklist Andrew Pinski
@ 2023-02-09 8:06 ` Richard Biener
2023-02-09 15:29 ` Andrew Pinski
0 siblings, 1 reply; 3+ messages in thread
From: Richard Biener @ 2023-02-09 8:06 UTC (permalink / raw)
To: Andrew Pinski; +Cc: gcc-patches, Andrew Macleod
On Wed, Feb 8, 2023 at 8:14 PM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> In simple_dce_from_worklist, we were removing an inline-asm which had a vdef
> (due to clobbering memory) but not unlinking the statement's vdef.
> This fixes that oversight. This was a latent bug exposed recently
> by both VRP and removal of stores to static starting to use
> simple_dce_from_worklist.
>
> OK for trunk (and for GCC 12 after a week)?
> Bootstrapped and tested on x86_64-linux-gnu with no regressions.
I think this is actually wrong-code - we cannot remove memory side-effects
of a stmt and the
/* The defining statement needs to be defining only this name.
ASM is the only statement that can define more than one
(non-virtual) name. */
if (is_a<gasm *>(t)
&& !single_ssa_def_operand (t, SSA_OP_DEF))
continue;
should use SSA_OP_ALL_DEFS instead.
OK with that change.
Richard.
> PR tree-optimization/108684
>
> gcc/ChangeLog:
>
> * tree-ssa-dce.cc (simple_dce_from_worklist):
> Call unlink_stmt_vdef on the statement before
> removing it.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.c-torture/compile/dce-inline-asm-1.c: New test.
> * gcc.c-torture/compile/dce-inline-asm-2.c: New test.
>
> co-authored-by: Andrew Macleod <amacleod@redhat.com>
> ---
> .../gcc.c-torture/compile/dce-inline-asm-1.c | 15 +++++++++++++++
> .../gcc.c-torture/compile/dce-inline-asm-2.c | 16 ++++++++++++++++
> gcc/tree-ssa-dce.cc | 1 +
> 3 files changed, 32 insertions(+)
> create mode 100644 gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c
> create mode 100644 gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c
>
> diff --git a/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c
> new file mode 100644
> index 00000000000..a9f02e44bd7
> --- /dev/null
> +++ b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c
> @@ -0,0 +1,15 @@
> +/* PR tree-optimization/108684 */
> +/* This used to ICE as when we remove the store to
> + `t`, we also would remove the inline-asm which
> + had a VDEF on it but we didn't update the
> + VUSE that was later on. */
> +static int t;
> +
> +int f (int *a)
> +{
> + int t1;
> + asm (" " : "=X" (t1) : : "memory");
> + t = t1;
> + return *a;
> +}
> +
> diff --git a/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c
> new file mode 100644
> index 00000000000..a41b16e4bd0
> --- /dev/null
> +++ b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c
> @@ -0,0 +1,16 @@
> +/* PR tree-optimization/108684 */
> +/* This used to ICE as when we removed the
> + __builtin_unreachable in VRP, as we
> + would also remove the branch and the
> + inline-asm. The inline-asm had a VDEF on it,
> + which we didn't update further along and
> + not have the VDEF on the return statement
> + updated. */
> +
> +int f (int a)
> +{
> + asm (" " : "=X" (a) : : "memory");
> + if (a)
> + return 0;
> + __builtin_unreachable();
> +}
> diff --git a/gcc/tree-ssa-dce.cc b/gcc/tree-ssa-dce.cc
> index b2fe9f4f55e..752785541e4 100644
> --- a/gcc/tree-ssa-dce.cc
> +++ b/gcc/tree-ssa-dce.cc
> @@ -2140,6 +2140,7 @@ simple_dce_from_worklist (bitmap worklist)
> remove_phi_node (&gsi, true);
> else
> {
> + unlink_stmt_vdef (t);
> gsi_remove (&gsi, true);
> release_defs (t);
> }
> --
> 2.31.1
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] tree-optimization: [PR108684] ICE in verify_ssa due to simple_dce_from_worklist
2023-02-09 8:06 ` Richard Biener
@ 2023-02-09 15:29 ` Andrew Pinski
0 siblings, 0 replies; 3+ messages in thread
From: Andrew Pinski @ 2023-02-09 15:29 UTC (permalink / raw)
To: Richard Biener; +Cc: Andrew Pinski, gcc-patches, Andrew Macleod
On Thu, Feb 9, 2023 at 12:07 AM Richard Biener via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> On Wed, Feb 8, 2023 at 8:14 PM Andrew Pinski via Gcc-patches
> <gcc-patches@gcc.gnu.org> wrote:
> >
> > In simple_dce_from_worklist, we were removing an inline-asm which had a vdef
> > (due to clobbering memory) but not unlinking the statement's vdef.
> > This fixes that oversight. This was a latent bug exposed recently
> > by both VRP and removal of stores to static starting to use
> > simple_dce_from_worklist.
> >
> > OK for trunk (and for GCC 12 after a week)?
> > Bootstrapped and tested on x86_64-linux-gnu with no regressions.
>
> I think this is actually wrong-code - we cannot remove memory side-effects
> of a stmt and the
>
> /* The defining statement needs to be defining only this name.
> ASM is the only statement that can define more than one
> (non-virtual) name. */
> if (is_a<gasm *>(t)
> && !single_ssa_def_operand (t, SSA_OP_DEF))
> continue;
>
> should use SSA_OP_ALL_DEFS instead.
Yes there is definitely wrong code. Will implement this change and add
a testcase which was being definitely being miscompiled (I put the
testcase in the bug report already).
Thanks,
Andrew Pinski
>
> OK with that change.
>
> Richard.
>
> > PR tree-optimization/108684
> >
> > gcc/ChangeLog:
> >
> > * tree-ssa-dce.cc (simple_dce_from_worklist):
> > Call unlink_stmt_vdef on the statement before
> > removing it.
> >
> > gcc/testsuite/ChangeLog:
> >
> > * gcc.c-torture/compile/dce-inline-asm-1.c: New test.
> > * gcc.c-torture/compile/dce-inline-asm-2.c: New test.
> >
> > co-authored-by: Andrew Macleod <amacleod@redhat.com>
> > ---
> > .../gcc.c-torture/compile/dce-inline-asm-1.c | 15 +++++++++++++++
> > .../gcc.c-torture/compile/dce-inline-asm-2.c | 16 ++++++++++++++++
> > gcc/tree-ssa-dce.cc | 1 +
> > 3 files changed, 32 insertions(+)
> > create mode 100644 gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c
> > create mode 100644 gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c
> >
> > diff --git a/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c
> > new file mode 100644
> > index 00000000000..a9f02e44bd7
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-1.c
> > @@ -0,0 +1,15 @@
> > +/* PR tree-optimization/108684 */
> > +/* This used to ICE as when we remove the store to
> > + `t`, we also would remove the inline-asm which
> > + had a VDEF on it but we didn't update the
> > + VUSE that was later on. */
> > +static int t;
> > +
> > +int f (int *a)
> > +{
> > + int t1;
> > + asm (" " : "=X" (t1) : : "memory");
> > + t = t1;
> > + return *a;
> > +}
> > +
> > diff --git a/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c
> > new file mode 100644
> > index 00000000000..a41b16e4bd0
> > --- /dev/null
> > +++ b/gcc/testsuite/gcc.c-torture/compile/dce-inline-asm-2.c
> > @@ -0,0 +1,16 @@
> > +/* PR tree-optimization/108684 */
> > +/* This used to ICE as when we removed the
> > + __builtin_unreachable in VRP, as we
> > + would also remove the branch and the
> > + inline-asm. The inline-asm had a VDEF on it,
> > + which we didn't update further along and
> > + not have the VDEF on the return statement
> > + updated. */
> > +
> > +int f (int a)
> > +{
> > + asm (" " : "=X" (a) : : "memory");
> > + if (a)
> > + return 0;
> > + __builtin_unreachable();
> > +}
> > diff --git a/gcc/tree-ssa-dce.cc b/gcc/tree-ssa-dce.cc
> > index b2fe9f4f55e..752785541e4 100644
> > --- a/gcc/tree-ssa-dce.cc
> > +++ b/gcc/tree-ssa-dce.cc
> > @@ -2140,6 +2140,7 @@ simple_dce_from_worklist (bitmap worklist)
> > remove_phi_node (&gsi, true);
> > else
> > {
> > + unlink_stmt_vdef (t);
> > gsi_remove (&gsi, true);
> > release_defs (t);
> > }
> > --
> > 2.31.1
> >
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-02-09 15:29 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2023-02-08 19:13 [PATCH] tree-optimization: [PR108684] ICE in verify_ssa due to simple_dce_from_worklist Andrew Pinski
2023-02-09 8:06 ` Richard Biener
2023-02-09 15:29 ` Andrew Pinski
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).