[PATCH] Fix vector division lowering (PR tree-optimization/60960)

[Jakub Jelinek]

Hi!

If a vector type has scalar mode, such as 4xchar vector in the testcase
SImode, then unfortunately various optabs checks in expand_vector_divmod
and functions it calls can succeed, but the operation is actually not
a vector operation (e.g. a SImode shift is very different from
V4QImode shift with scalar shift count).

The following patch fixes this by not calling expand_vector_divmod
at all if the type doesn't have a vector mode.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/4.9?

2014-04-25  Jakub Jelinek  <ja...@redhat.com>

        PR tree-optimization/60960
        * tree-vect-generic.c (expand_vector_operation): Only call
        expand_vector_divmod if type's mode satisfies VECTOR_MODE_P.

        * gcc.c-torture/execute/pr60960.c: New test.

--- gcc/tree-vect-generic.c.jj  2014-04-17 14:49:04.000000000 +0200
+++ gcc/tree-vect-generic.c     2014-04-25 09:27:31.689530647 +0200
@@ -971,7 +971,8 @@ expand_vector_operation (gimple_stmt_ite
 
          if (!optimize
              || !VECTOR_INTEGER_TYPE_P (type)
-             || TREE_CODE (rhs2) != VECTOR_CST)
+             || TREE_CODE (rhs2) != VECTOR_CST
+             || !VECTOR_MODE_P (TYPE_MODE (type)))
            break;
 
          ret = expand_vector_divmod (gsi, type, rhs1, rhs2, code);
--- gcc/testsuite/gcc.c-torture/execute/pr60960.c.jj    2014-04-25 
09:30:10.891687231 +0200
+++ gcc/testsuite/gcc.c-torture/execute/pr60960.c       2014-04-25 
09:29:50.000000000 +0200
@@ -0,0 +1,38 @@
+/* PR tree-optimization/60960 */
+
+typedef unsigned char v4qi __attribute__ ((vector_size (4)));
+
+__attribute__((noinline, noclone)) v4qi
+f1 (v4qi v)
+{
+  return v / 2;
+}
+
+__attribute__((noinline, noclone)) v4qi
+f2 (v4qi v)
+{
+  return v / (v4qi) { 2, 2, 2, 2 };
+}
+
+__attribute__((noinline, noclone)) v4qi
+f3 (v4qi x, v4qi y)
+{
+  return x / y;
+}
+
+int
+main ()
+{
+  v4qi x = { 5, 5, 5, 5 };
+  v4qi y = { 2, 2, 2, 2 };
+  v4qi z = f1 (x);
+  if (__builtin_memcmp (&y, &z, sizeof (y)) != 0)
+    __builtin_abort ();
+  z = f2 (x);
+  if (__builtin_memcmp (&y, &z, sizeof (y)) != 0)
+    __builtin_abort ();
+  z = f3 (x, y);
+  if (__builtin_memcmp (&y, &z, sizeof (y)) != 0)
+    __builtin_abort ();
+  return 0;
+}

        Jakub