[Bug c++/70438] New: result type of vector operations

[mjh at edg dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70438

            Bug ID: 70438
           Summary: result type of vector operations
           Product: gcc
           Version: 5.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: mjh at edg dot com
  Target Milestone: ---

The documentation for Vector Extensions says that the relational operations and
logical operations return vectors of the same width and number of elements as
the operands, but with signed integral element type.

In the following example, operations are performed on a vector of floats and an
attempt is made to to assign the result to the same vector, expecting an error,
but no errors are diagnosed.  Errors are, however, given when an incompatible
vector type is assigned directly:

typedef float v4sf __attribute__ ((vector_size (16)));
typedef int v4si __attribute__ ((vector_size (16)));
int main() {
  v4sf c = {1.0,0.0,1.0,0.0};
  v4si x;
  /* These assignments are allowed (but shouldn't be?): */
  c = !c;
  c = c && c;
  c = c || c;
  c = c == c;
  c = c != c;
  c = c >= c;
  c = c <= c;
  c = c < c;
  c = c > c;
#if NEG
  /* These assignments are not allowed: */
  c = x;
  c = (v4si){1};
#endif
  return 0;
}

I would expect all of these to elicit an error.  Am I missing something or is
this a bug?