[pushed] c++: TARGET_EXPR collapsing [PR107303]

[pushed] c++: TARGET_EXPR collapsing [PR107303]

[Jason Merrill]

Tested x86_64-pc-linux-gnu, applying to trunk.

-- 8< --

In r13-2978 I tried to eliminate TARGET_EXPR around TARGET_EXPR by
discarding the outer one, but as in this testcase that breaks if the
TARGET_EXPR_SLOT of the outer one is used elsewhere.  But it should always
be safe to strip the inner one; if its slot were reused, there would be a
COMPOUND_EXPR around the TARGET_EXPR.

For 107329, if we're setting *walk_subtrees, we also need to fold
TARGET_EXPR_CLEANUP.

	PR c++/107303
	PR c++/107329

gcc/cp/ChangeLog:

	* cp-gimplify.cc (cp_fold_r) [TARGET_EXPR]: In case of double
	TARGET_EXPR, keep the outer one instead of the inner one.
	(maybe_replace_decl): New.

gcc/testsuite/ChangeLog:

	* g++.dg/ext/builtin-shufflevector-5.C: New test.
	* g++.dg/init/new51.C: New test.
---
 gcc/cp/cp-gimplify.cc                         | 31 +++++++++++++++++--
 .../g++.dg/ext/builtin-shufflevector-5.C      | 14 +++++++++
 gcc/testsuite/g++.dg/init/new51.C             | 10 ++++++
 3 files changed, 52 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/g++.dg/ext/builtin-shufflevector-5.C
 create mode 100644 gcc/testsuite/g++.dg/init/new51.C

diff --git a/gcc/cp/cp-gimplify.cc b/gcc/cp/cp-gimplify.cc
index 83ba1285bfd..92cd309e670 100644
--- a/gcc/cp/cp-gimplify.cc
+++ b/gcc/cp/cp-gimplify.cc
@@ -952,6 +952,28 @@ cp_genericize_target_expr (tree *stmt_p)
   gcc_assert (!DECL_INITIAL (slot));
 }
 
+/* Similar to if (target_expr_needs_replace) replace_decl, but TP is the
+   TARGET_EXPR_INITIAL, and this also updates *_SLOT.  We need this extra
+   replacement when cp_folding TARGET_EXPR to preserve the invariant that
+   AGGR_INIT_EXPR_SLOT agrees with the enclosing TARGET_EXPR_SLOT.  */
+
+bool
+maybe_replace_decl (tree *tp, tree decl, tree replacement)
+{
+  if (!*tp || !VOID_TYPE_P (TREE_TYPE (*tp)))
+    return false;
+  tree t = *tp;
+  while (TREE_CODE (t) == COMPOUND_EXPR)
+    t = TREE_OPERAND (t, 1);
+  if (TREE_CODE (t) == AGGR_INIT_EXPR)
+    replace_decl (&AGGR_INIT_EXPR_SLOT (t), decl, replacement);
+  else if (TREE_CODE (t) == VEC_INIT_EXPR)
+    replace_decl (&VEC_INIT_EXPR_SLOT (t), decl, replacement);
+  else
+    replace_decl (tp, decl, replacement);
+  return true;
+}
+
 /* Genericization context.  */
 
 struct cp_genericize_data
@@ -1116,15 +1138,18 @@ cp_fold_r (tree *stmt_p, int *walk_subtrees, void *data_)
 	cp_genericize_target_expr (stmt_p);
 
       /* Folding might replace e.g. a COND_EXPR with a TARGET_EXPR; in
-	 that case, use it in place of this one.  */
+	 that case, strip it in favor of this one.  */
       if (tree &init = TARGET_EXPR_INITIAL (stmt))
 	{
 	  cp_walk_tree (&init, cp_fold_r, data, NULL);
+	  cp_walk_tree (&TARGET_EXPR_CLEANUP (stmt), cp_fold_r, data, NULL);
 	  *walk_subtrees = 0;
 	  if (TREE_CODE (init) == TARGET_EXPR)
 	    {
-	      TARGET_EXPR_ELIDING_P (init) = TARGET_EXPR_ELIDING_P (stmt);
-	      *stmt_p = init;
+	      tree sub = TARGET_EXPR_INITIAL (init);
+	      maybe_replace_decl (&sub, TARGET_EXPR_SLOT (init),
+				  TARGET_EXPR_SLOT (stmt));
+	      init = sub;
 	    }
 	}
       break;
diff --git a/gcc/testsuite/g++.dg/ext/builtin-shufflevector-5.C b/gcc/testsuite/g++.dg/ext/builtin-shufflevector-5.C
new file mode 100644
index 00000000000..06472b8d86b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/builtin-shufflevector-5.C
@@ -0,0 +1,14 @@
+// PR c++/107303
+// { dg-options "-Wno-psabi" }
+
+typedef __attribute__((__vector_size__ (2))) unsigned short U;
+typedef __attribute__((__vector_size__ (8))) unsigned short V;
+
+U u0, u1, u2;
+V v;
+
+void
+foo (void)
+{
+  u0 *= +__builtin_shufflevector (__builtin_shufflevector (u1, v, 3, 1), u2, 0);
+}
diff --git a/gcc/testsuite/g++.dg/init/new51.C b/gcc/testsuite/g++.dg/init/new51.C
new file mode 100644
index 00000000000..d8b336476d9
--- /dev/null
+++ b/gcc/testsuite/g++.dg/init/new51.C
@@ -0,0 +1,10 @@
+// PR c++/107329
+
+struct RexxClass {
+  void *operator new(unsigned long, unsigned long, const char *, RexxClass *,
+                     RexxClass *);
+  void operator delete(void *, unsigned long, const char *, RexxClass *,
+                       RexxClass *);
+  RexxClass();
+};
+void createInstance() { new (sizeof(RexxClass), "", 0, 0) RexxClass; }

base-commit: 4cbc71691e47b1ca6b64feb0af678606705d2f92
-- 
2.31.1

[committed] testsuite: Fix up new51.C test on various targets [PR108533]

[Jakub Jelinek]

On Mon, Jan 23, 2023 at 10:26:14PM -0500, Jason Merrill via Gcc-patches wrote:
> 	* g++.dg/init/new51.C: New test.

The test fails on targets where size_t is not unsigned long
due to extra diagnostics.

As the testcase is tested in C++98 too, I'm not using decltype (sizeof 0)
but __SIZE_TYPE__.

Tested on x86_64-linux and i686-linux (plus verified with older snapshots
that it ICEs even with the change with both -m32/-m64), committed to
trunk as obvious.

2023-01-25  Jakub Jelinek  <jakub@redhat.com>

	PR c++/107329
	PR testsuite/108533
	* g++.dg/init/new51.C (size_t): New typedef.
	(RexxClass::operator new, RexxClass::operator delete): Use size_t
	instead of unsigned long.

--- gcc/testsuite/g++.dg/init/new51.C.jj	2023-01-24 11:10:13.000000000 +0100
+++ gcc/testsuite/g++.dg/init/new51.C	2023-01-25 00:05:10.767472447 +0100
@@ -1,9 +1,10 @@
 // PR c++/107329
 
+typedef __SIZE_TYPE__ size_t;
 struct RexxClass {
-  void *operator new(unsigned long, unsigned long, const char *, RexxClass *,
+  void *operator new(size_t, size_t, const char *, RexxClass *,
                      RexxClass *);
-  void operator delete(void *, unsigned long, const char *, RexxClass *,
+  void operator delete(void *, size_t, const char *, RexxClass *,
                        RexxClass *);
   RexxClass();
 };

	Jakub

Re: [committed] testsuite: Fix up new51.C test on various targets [PR108533]

[Jason Merrill]

On 1/24/23 18:16, Jakub Jelinek wrote:
> On Mon, Jan 23, 2023 at 10:26:14PM -0500, Jason Merrill via Gcc-patches wrote:
>> 	* g++.dg/init/new51.C: New test.
> 
> The test fails on targets where size_t is not unsigned long
> due to extra diagnostics.
> 
> As the testcase is tested in C++98 too, I'm not using decltype (sizeof 0)
> but __SIZE_TYPE__.
> 
> Tested on x86_64-linux and i686-linux (plus verified with older snapshots
> that it ICEs even with the change with both -m32/-m64), committed to
> trunk as obvious.

Thanks.

> 2023-01-25  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR c++/107329
> 	PR testsuite/108533
> 	* g++.dg/init/new51.C (size_t): New typedef.
> 	(RexxClass::operator new, RexxClass::operator delete): Use size_t
> 	instead of unsigned long.
> 
> --- gcc/testsuite/g++.dg/init/new51.C.jj	2023-01-24 11:10:13.000000000 +0100
> +++ gcc/testsuite/g++.dg/init/new51.C	2023-01-25 00:05:10.767472447 +0100
> @@ -1,9 +1,10 @@
>   // PR c++/107329
>   
> +typedef __SIZE_TYPE__ size_t;
>   struct RexxClass {
> -  void *operator new(unsigned long, unsigned long, const char *, RexxClass *,
> +  void *operator new(size_t, size_t, const char *, RexxClass *,
>                        RexxClass *);
> -  void operator delete(void *, unsigned long, const char *, RexxClass *,
> +  void operator delete(void *, size_t, const char *, RexxClass *,
>                          RexxClass *);
>     RexxClass();
>   };
> 
> 	Jakub
>