* [COMMITTED] tree-optimization: [PR108684] ICE in verify_ssa due to simple_dce_from_worklist
@ 2023-02-10 1:43 Andrew Pinski
2023-02-10 7:46 ` Richard Biener
0 siblings, 1 reply; 2+ messages in thread
From: Andrew Pinski @ 2023-02-10 1:43 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.
We should not be removing inline-asm which have a vdef as this code
does not check to the store.
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.
Committed as approved.
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):
Check all ssa names and not just non-vdef ones
before accepting the inline-asm.
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.
* gcc.dg/tree-ssa/pr108684-1.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/testsuite/gcc.dg/tree-ssa/pr108684-1.c | 18 ++++++++++++++++++
gcc/tree-ssa-dce.cc | 5 +++--
4 files changed, 52 insertions(+), 2 deletions(-)
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
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr108684-1.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/testsuite/gcc.dg/tree-ssa/pr108684-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr108684-1.c
new file mode 100644
index 00000000000..3ba206f765e
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr108684-1.c
@@ -0,0 +1,18 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+
+static int t;
+
+int f (int *a)
+{
+ int t1, t2 = 0;
+ asm ("shouldshowupstill %1" : "=r" (t1), "=m"(t2) : : );
+ t = t1;
+ return t2;
+}
+
+/* Check to make sure DCE does not remove the inline-asm as it writes to t2. */
+/* We used to DCE this inline-asm when removing the store to t. */
+/* { dg-final { scan-assembler "shouldshowupstill" } } */
+/* { dg-final { scan-tree-dump-times "shouldshowupstill" 1 "optimized" } } */
diff --git a/gcc/tree-ssa-dce.cc b/gcc/tree-ssa-dce.cc
index b2fe9f4f55e..1f1ec2c8710 100644
--- a/gcc/tree-ssa-dce.cc
+++ b/gcc/tree-ssa-dce.cc
@@ -2108,9 +2108,9 @@ simple_dce_from_worklist (bitmap worklist)
/* The defining statement needs to be defining only this name.
ASM is the only statement that can define more than one
- (non-virtual) name. */
+ name. */
if (is_a<gasm *>(t)
- && !single_ssa_def_operand (t, SSA_OP_DEF))
+ && !single_ssa_def_operand (t, SSA_OP_ALL_DEFS))
continue;
/* Don't remove statements that are needed for non-call
@@ -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);
}
--
2.27.0
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [COMMITTED] tree-optimization: [PR108684] ICE in verify_ssa due to simple_dce_from_worklist
2023-02-10 1:43 [COMMITTED] tree-optimization: [PR108684] ICE in verify_ssa due to simple_dce_from_worklist Andrew Pinski
@ 2023-02-10 7:46 ` Richard Biener
0 siblings, 0 replies; 2+ messages in thread
From: Richard Biener @ 2023-02-10 7:46 UTC (permalink / raw)
To: Andrew Pinski; +Cc: gcc-patches, Andrew Macleod
On Fri, Feb 10, 2023 at 2:47 AM 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.
> We should not be removing inline-asm which have a vdef as this code
> does not check to the store.
> 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.
>
> Committed as approved.
> 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):
> Check all ssa names and not just non-vdef ones
> before accepting the inline-asm.
> 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.
> * gcc.dg/tree-ssa/pr108684-1.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/testsuite/gcc.dg/tree-ssa/pr108684-1.c | 18 ++++++++++++++++++
> gcc/tree-ssa-dce.cc | 5 +++--
> 4 files changed, 52 insertions(+), 2 deletions(-)
> 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
> create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr108684-1.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/testsuite/gcc.dg/tree-ssa/pr108684-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr108684-1.c
> new file mode 100644
> index 00000000000..3ba206f765e
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr108684-1.c
> @@ -0,0 +1,18 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +
> +
> +static int t;
> +
> +int f (int *a)
> +{
> + int t1, t2 = 0;
> + asm ("shouldshowupstill %1" : "=r" (t1), "=m"(t2) : : );
> + t = t1;
> + return t2;
> +}
> +
> +/* Check to make sure DCE does not remove the inline-asm as it writes to t2. */
> +/* We used to DCE this inline-asm when removing the store to t. */
> +/* { dg-final { scan-assembler "shouldshowupstill" } } */
> +/* { dg-final { scan-tree-dump-times "shouldshowupstill" 1 "optimized" } } */
> diff --git a/gcc/tree-ssa-dce.cc b/gcc/tree-ssa-dce.cc
> index b2fe9f4f55e..1f1ec2c8710 100644
> --- a/gcc/tree-ssa-dce.cc
> +++ b/gcc/tree-ssa-dce.cc
> @@ -2108,9 +2108,9 @@ simple_dce_from_worklist (bitmap worklist)
>
> /* The defining statement needs to be defining only this name.
> ASM is the only statement that can define more than one
> - (non-virtual) name. */
> + name. */
> if (is_a<gasm *>(t)
> - && !single_ssa_def_operand (t, SSA_OP_DEF))
> + && !single_ssa_def_operand (t, SSA_OP_ALL_DEFS))
> continue;
>
> /* Don't remove statements that are needed for non-call
> @@ -2140,6 +2140,7 @@ simple_dce_from_worklist (bitmap worklist)
> remove_phi_node (&gsi, true);
> else
> {
> + unlink_stmt_vdef (t);
note this should never do anything
> gsi_remove (&gsi, true);
> release_defs (t);
> }
> --
> 2.27.0
>
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2023-02-10 7:46 ` Richard Biener
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