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From: "Martin Liška" <mliska@suse.cz>
To: gcc-patches@gcc.gnu.org
Cc: Jakub Jelinek <jakub@redhat.com>
Subject: [PATCH] Fix __builtin_clear_padding for empty struct.
Date: Wed, 2 Dec 2020 10:25:32 +0100	[thread overview]
Message-ID: <730211eb-43b3-aa04-dc66-22f53b715b88@suse.cz> (raw)

It's a simple fix of a division by zero.

Patch can bootstrap on x86_64-linux-gnu and survives regression tests.

Ready to be installed?
Thanks,
Martin

gcc/ChangeLog:

	PR c/98087
	* gimple-fold.c (clear_padding_type): Do not divide by zero.

gcc/testsuite/ChangeLog:

	PR c/98087
	* gcc.c-torture/compile/pr98087.c: New test.
---
  gcc/gimple-fold.c                             | 2 ++
  gcc/testsuite/gcc.c-torture/compile/pr98087.c | 8 ++++++++
  2 files changed, 10 insertions(+)
  create mode 100644 gcc/testsuite/gcc.c-torture/compile/pr98087.c

diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index 1f3d80e2881..ab74494703a 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -4552,6 +4552,8 @@ clear_padding_type (clear_padding_struct *buf, tree type, HOST_WIDE_INT sz)
      case ARRAY_TYPE:
        HOST_WIDE_INT nelts, fldsz;
        fldsz = int_size_in_bytes (TREE_TYPE (type));
+      if (fldsz == 0)
+	break;
        nelts = sz / fldsz;
        if (nelts > 1
  	  && sz > 8 * UNITS_PER_WORD
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr98087.c b/gcc/testsuite/gcc.c-torture/compile/pr98087.c
new file mode 100644
index 00000000000..9f0e5c4be7d
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr98087.c
@@ -0,0 +1,8 @@
+/* PR c/98087 */
+
+struct S {};
+void foo (int n)
+{
+  struct S a[n][0];
+  __builtin_clear_padding (a);
+}
-- 
2.29.2


             reply	other threads:[~2020-12-02  9:25 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-02  9:25 Martin Liška [this message]
2020-12-02 10:11 ` Jakub Jelinek
2020-12-02 10:32   ` Martin Liška

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