Re: [PATCH] x86: Always update EH return address in word_mode

[H.J. Lu]

On Mon, Aug 20, 2018 at 11:40 AM, Uros Bizjak <ubiz...@gmail.com> wrote:
> On Mon, Aug 20, 2018 at 8:19 PM, H.J. Lu <hongjiu...@intel.com> wrote:
>> On x86, return address is always popped in word_mode.  eh_return needs
>> to put EH return address in word_mode on stack.
>>
>> Tested on x86-64 with x32. OK for trunk and release branches?
>
> OK. Perhaps the testcase should go into g++.dg/torture, since it is
> sensitive to optimization level?

Sure.  This is the patch I am checking in.

Thanks.

-- 
H.J.

From 62605355f506d4f163b6102ae0db67b19c3df756 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.to...@gmail.com>
Date: Mon, 20 Aug 2018 10:04:35 -0700
Subject: [PATCH] x86: Always update EH return address in word_mode

On x86, return address is always popped in word_mode.  eh_return needs
to put EH return address in word_mode on stack.

gcc/

	PR target/87014
	* config/i386/i386.md (eh_return): Always update EH return
	address in word_mode.

gcc/testsuite/

	PR target/87014
	* g++.dg/torture/pr87014.C: New file.
---
 gcc/config/i386/i386.md                |  5 +++-
 gcc/testsuite/g++.dg/torture/pr87014.C | 37 ++++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/g++.dg/torture/pr87014.C

diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 918241d953a..71faa218ffa 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -13612,7 +13612,10 @@
      stack address we wish to restore.  */
   tmp = gen_rtx_PLUS (Pmode, arg_pointer_rtx, sa);
   tmp = plus_constant (Pmode, tmp, -UNITS_PER_WORD);
-  tmp = gen_rtx_MEM (Pmode, tmp);
+  /* Return address is always in word_mode.  */
+  tmp = gen_rtx_MEM (word_mode, tmp);
+  if (GET_MODE (ra) != word_mode)
+    ra = convert_to_mode (word_mode, ra, 1);
   emit_move_insn (tmp, ra);
 
   emit_jump_insn (gen_eh_return_internal ());
diff --git a/gcc/testsuite/g++.dg/torture/pr87014.C b/gcc/testsuite/g++.dg/torture/pr87014.C
new file mode 100644
index 00000000000..614954ef464
--- /dev/null
+++ b/gcc/testsuite/g++.dg/torture/pr87014.C
@@ -0,0 +1,37 @@
+// { dg-do run }
+
+void
+fillstack ()
+{
+  long long foo[] =
+    {
+      -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+    };
+}
+
+void
+f (long long=-1,long long=-1,long long=-1,long long=-1,
+   long long=-1,long long=-1,long long arg7_on_stack=-1)
+{
+  throw 0;
+}
+
+void
+g()
+{
+  try
+    {
+      f ();
+    }
+  catch (int)
+    {
+    }
+}
+
+int
+main()
+{
+  fillstack ();
+  g ();
+  return 0;
+}
-- 
2.17.1