PR middle-end/93200 - spurious -Wstringop-overflow due to assignment vectorization to multiple members

PR middle-end/93200 - spurious -Wstringop-overflow due to assignment vectorization to multiple members
PR fortran/92956 - 'libgomp.fortran/examples-4/async_target-2.f90' fails with offloading due to bogus -Wstringop-overflow warning

gcc/testsuite/ChangeLog:

	PR middle-end/93200
	* gcc.dg/Wstringop-overflow-30.c: New test.

gcc/ChangeLog:

	PR middle-end/93200
	PR fortran/92956
	* builtins.c (compute_objsize): Avoid handling MEM_REFs of vector type.

From-SVN: r280041

4 files changed, 103 insertions, 0 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 0891e98..bddbf8c 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2020-01-09  Martin Sebor  <msebor@redhat.com>
+
+	PR middle-end/93200
+	PR fortran/92956
+	* builtins.c (compute_objsize): Avoid handling MEM_REFs of vector type.
+
 2020-01-09  Martin Liska  <mliska@suse.cz>
 
 	* auto-profile.c (auto_profile): Use opt_for_fn
diff --git a/gcc/builtins.c b/gcc/builtins.c
index 1f70298..e4a8694 100644
--- a/gcc/builtins.c
+++ b/gcc/builtins.c
@@ -3966,6 +3966,18 @@ compute_objsize (tree dest, int ostype, tree *pdecl /* = NULL */,
       || TREE_CODE (dest) == MEM_REF)
     {
       tree ref = TREE_OPERAND (dest, 0);
+      tree reftype = TREE_TYPE (ref);
+      if (TREE_CODE (dest) == MEM_REF && TREE_CODE (reftype) == POINTER_TYPE)
+	{
+	  /* Give up for MEM_REFs of vector types; those may be synthesized
+	     from multiple assignments to consecutive data members.  See PR
+	     93200.
+	     FIXME: Deal with this more generally, e.g., by marking up such
+	     MEM_REFs at the time they're created.  */
+	  reftype = TREE_TYPE (reftype);
+	  if (TREE_CODE (reftype) == VECTOR_TYPE)
+	    return NULL_TREE;
+	}
       tree off = TREE_OPERAND (dest, 1);
       if (tree size = compute_objsize (ref, ostype, pdecl, poff))
 	{
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 71106d1..db6e960 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2020-01-09  Martin Sebor  <msebor@redhat.com>
+
+	PR middle-end/93200
+	* gcc.dg/Wstringop-overflow-30.c: New test.
+
 2020-01-09  Richard Biener  <rguenther@suse.de>
 
 	PR middle-end/93054
diff --git a/gcc/testsuite/gcc.dg/Wstringop-overflow-30.c b/gcc/testsuite/gcc.dg/Wstringop-overflow-30.c
new file mode 100644
index 0000000..a9eee99
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wstringop-overflow-30.c
@@ -0,0 +1,80 @@
+/* PR middle-end/93200 - spurious -Wstringop-overflow due to assignment
+   vectorization to multiple members
+   { dg-do compile }
+   { dg-options "-O3 -Wall" } */
+
+typedef __INT8_TYPE__  int8_t;
+typedef __INT16_TYPE__ int16_t;
+typedef __INT32_TYPE__ int32_t;
+typedef __INT64_TYPE__ int64_t;
+
+struct A { char b, c; };
+struct B1A { int8_t i8; struct A a; };
+struct B2A { int16_t i16; struct A a; };
+struct B3A { int16_t i16; int8_t i8; struct A a; };
+struct B4A { int64_t i64; struct A a; };
+
+void ba1 (struct B1A *p)
+{
+  p->a.b = 0; p->a.c = 1;
+}
+
+void b2a (struct B2A *p)
+{
+  /* This results in:
+     vector(2) char *vectp.14_6 = &p_2(D)->a.b;
+     MEM <vector(2) char> [(char *)vectp.14_6] = { 4, 5 };  */
+
+  p->a.b = 4;       // { dg-bogus "-Wstringop-overflow" }
+  p->a.c = 5;
+}
+
+void b3a (struct B3A *p)
+{
+  p->a.b = 4; p->a.c = 5;
+}
+
+void b4a (struct B4A *p)
+{
+  /* This results in:
+     vector(2) char *vectp.22_6 = &p_2(D)->a.b;
+     MEM <vector(2) char> [(char *)vectp.22_6] = { 6, 7 };  */
+
+  p->a.b = 6;       // { dg-bogus "-Wstringop-overflow" }
+  p->a.c = 7;
+}
+
+
+struct Aa { char a[2], b[2]; };
+struct B1Aa { int8_t i8; struct Aa a; };
+struct B2Aa { int16_t i16; struct Aa a; };
+struct B3Aa { int16_t i16; int8_t i8; struct Aa a; };
+struct B4Aa { int64_t i64; struct Aa a; };
+
+void b1aa (struct B1Aa *p)
+{
+  p->a.a[0] = 0; p->a.a[1] = 1;
+  p->a.b[0] = 0; p->a.b[1] = 1;
+}
+
+void b2aa (struct B2Aa *p)
+{
+  p->a.a[0] = 2; p->a.a[1] = 3;
+  p->a.b[0] = 2; p->a.b[1] = 3;
+}
+
+void b3aa (struct B3Aa *p)
+{
+  p->a.a[0] = 4; p->a.a[1] = 5;
+  p->a.b[0] = 4; p->a.b[1] = 5;
+}
+
+void b4aa (struct B4Aa *p)
+{
+  /* This results in:
+     vector(4) char *vectp.36_8 = &p_2(D)->a.a[0];
+     MEM <vector(4) char> [(char *)vectp.36_8] = { 6, 7, 6, 7 };  */
+
+  p->a.a[0] = 6; p->a.a[1] = 7;
+  p->a.b[0] = 6; p->a.b[1] = 7;
+}