re PR rtl-optimization/83682 (ICE in simplify_subreg, at simplify-rtx.c:6296)

	PR rtl-optimization/83682
	* rtl.h (const_vec_duplicate_p): Only return true for VEC_DUPLICATE
	if it has non-VECTOR_MODE element mode.
	(vec_duplicate_p): Likewise.

	* gcc.target/i386/pr83682.c: New test.

From-SVN: r256308

gcc/ChangeLog

 2018-01-06  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/83682
+	* rtl.h (const_vec_duplicate_p): Only return true for VEC_DUPLICATE
+	if it has non-VECTOR_MODE element mode.
+	(vec_duplicate_p): Likewise.
+
 	PR middle-end/83694
 	* cfgexpand.c (expand_debug_expr): Punt if mode1 is VOIDmode
 	and bitsize might be greater than MAX_BITSIZE_MODE_ANY_INT.

gcc/rtl.h

@@ -2969,7 +2969,9 @@ const_vec_duplicate_p (T x, T *elt)
       *elt = CONST_VECTOR_ENCODED_ELT (x, 0);
       return true;
     }
-  if (GET_CODE (x) == CONST && GET_CODE (XEXP (x, 0)) == VEC_DUPLICATE)
+  if (GET_CODE (x) == CONST
+      && GET_CODE (XEXP (x, 0)) == VEC_DUPLICATE
+      && !VECTOR_MODE_P (GET_MODE (XEXP (XEXP (x, 0), 0))))
     {
       *elt = XEXP (XEXP (x, 0), 0);
       return true;
@@ -2984,7 +2986,8 @@ template <typename T>
 inline bool
 vec_duplicate_p (T x, T *elt)
 {
-  if (GET_CODE (x) == VEC_DUPLICATE)
+  if (GET_CODE (x) == VEC_DUPLICATE
+      && !VECTOR_MODE_P (GET_MODE (XEXP (x, 0))))
     {
       *elt = XEXP (x, 0);
       return true;

gcc/testsuite/ChangeLog

+2018-01-06  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/83682
+	* gcc.target/i386/pr83682.c: New test.
+
 2018-01-05  Janne Blomqvist  <jb@gcc.gnu.org>
 
 	PR fortran/78534

gcc/testsuite/gcc.target/i386/pr83682.c

+/* PR rtl-optimization/83682 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -msse2" } */
+
+typedef float V __attribute__((__vector_size__(16)));
+typedef double W __attribute__((__vector_size__(16)));
+V b;
+W c;
+
+void
+foo (void *p)
+{
+  V e = __builtin_ia32_cvtsd2ss (b, c);
+  V g = e;
+  float f = g[0];
+  __builtin_memcpy (p, &f, sizeof (f));
+}