simd-1.c: New.

2002-06-16  Aldy Hernandez  <aldyh@redhat.com>

	* gcc.c-torture/execute/simd-1.c: New.

	* gcc.dg/simd-1.c: New.

	* doc/extend.texi (Vector Extensions): Document that we can
	specify simd types not specifically supported by the hardware.
	Document that simd types can be used as function arguments.
	Document that signness does make a difference in SIMD types.
	Misc cleanups and revisions to the "vector extensions" section.

	* simplify-rtx.c (simplify_subreg): Simplify subregs of vector
	constants.

	* expr.c (vector_mode_valid_p): New.

	* expr.h: Add vector_mode_valid_p.

	* defaults.h (VECTOR_MODE_SUPPORTED_P): Set default.

	* emit-rtl.c (immed_double_const): Do not abort on vectors.

	* c-common.c (type_for_mode): Always build vector nodes regardless
	of VECTOR_MODE_SUPPORTED_P.
	(handle_mode_attribute): Error if we can't emulate a nonexisting
	vector mode.
	(handle_vector_size_attribute): Same.

	* optabs.c (expand_binop): Open-code vector operations.
	(expand_unop): Open-code vector unops.
	(expand_vector_binop): New.
	(expand_vector_unop): New.

	* c-typeck.c (build_binary_op): Allow vectors in binops.
	Allow vectors in conditional operatiors.
	(build_unary_op): Allow vectors in unary minus.

	* config/rs6000/rs6000.h (ALTIVEC_VECTOR_MODE): Conditionalize on
	TARGET_ALTIVEC.

From-SVN: r54727

gcc/c-common.c

@@ -1602,38 +1602,33 @@ c_common_type_for_mode (mode, unsignedp)
   if (mode == TYPE_MODE (build_pointer_type (integer_type_node)))
     return build_pointer_type (integer_type_node);
 
-#ifdef VECTOR_MODE_SUPPORTED_P
-  if (VECTOR_MODE_SUPPORTED_P (mode))
-    {
-      switch (mode)
-	{
-	case V16QImode:
-	  return unsignedp ? unsigned_V16QI_type_node : V16QI_type_node;
-	case V8HImode:
-	  return unsignedp ? unsigned_V8HI_type_node : V8HI_type_node;
-	case V4SImode:
-	  return unsignedp ? unsigned_V4SI_type_node : V4SI_type_node;
-	case V2DImode:
-	  return unsignedp ? unsigned_V2DI_type_node : V2DI_type_node;
-	case V2SImode:
-	  return unsignedp ? unsigned_V2SI_type_node : V2SI_type_node;
-	case V4HImode:
-	  return unsignedp ? unsigned_V4HI_type_node : V4HI_type_node;
-	case V8QImode:
-	  return unsignedp ? unsigned_V8QI_type_node : V8QI_type_node;
-	case V16SFmode:
-	  return V16SF_type_node;
-	case V4SFmode:
-	  return V4SF_type_node;
-	case V2SFmode:
-	  return V2SF_type_node;
-	case V2DFmode:
-	  return V2DF_type_node;
-	default:
-	  break;
-	}
+  switch (mode)
+    {
+    case V16QImode:
+      return unsignedp ? unsigned_V16QI_type_node : V16QI_type_node;
+    case V8HImode:
+      return unsignedp ? unsigned_V8HI_type_node : V8HI_type_node;
+    case V4SImode:
+      return unsignedp ? unsigned_V4SI_type_node : V4SI_type_node;
+    case V2DImode:
+      return unsignedp ? unsigned_V2DI_type_node : V2DI_type_node;
+    case V2SImode:
+      return unsignedp ? unsigned_V2SI_type_node : V2SI_type_node;
+    case V4HImode:
+      return unsignedp ? unsigned_V4HI_type_node : V4HI_type_node;
+    case V8QImode:
+      return unsignedp ? unsigned_V8QI_type_node : V8QI_type_node;
+    case V16SFmode:
+      return V16SF_type_node;
+    case V4SFmode:
+      return V4SF_type_node;
+    case V2SFmode:
+      return V2SF_type_node;
+    case V2DFmode:
+      return V2DF_type_node;
+    default:
+      break;
     }
-#endif
 
   return 0;
 }
@@ -5058,8 +5053,20 @@ handle_mode_attribute (node, name, args, flags, no_add_attrs)
 		     (mode, TREE_UNSIGNED (type))))
 	error ("no data type for mode `%s'", p);
       else
-	*node = typefm;
-        /* No need to layout the type here.  The caller should do this.  */
+	{
+	  /* If this is a vector, make sure we either have hardware
+	     support, or we can emulate it.  */
+	  if ((GET_MODE_CLASS (mode) == MODE_VECTOR_INT
+	       || GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
+	      && !vector_mode_valid_p (mode))
+	    {
+	      error ("unable to emulate '%s'", GET_MODE_NAME (mode));
+	      return NULL_TREE;
+	    }
+
+	  *node = typefm;
+	  /* No need to layout the type here.  The caller should do this.  */
+	}
     }
 
   return NULL_TREE;
@@ -5604,6 +5611,16 @@ handle_vector_size_attribute (node, name, args, flags, no_add_attrs)
 
       new_type = build_type_copy (new_type);
 
+      /* If this is a vector, make sure we either have hardware
+         support, or we can emulate it.  */
+      if ((GET_MODE_CLASS (mode) == MODE_VECTOR_INT
+	   || GET_MODE_CLASS (mode) == MODE_VECTOR_FLOAT)
+	  && !vector_mode_valid_p (mode))
+	{
+	  error ("unable to emulate '%s'", GET_MODE_NAME (mode));
+	  return NULL_TREE;
+	}
+
       /* Set the debug information here, because this is the only
 	 place where we know the underlying type for a vector made
 	 with vector_size.  For debugging purposes we pretend a vector

gcc/c-typeck.c

@@ -2046,9 +2046,9 @@ build_binary_op (code, orig_op0, orig_op1, convert_p)
 	warning ("division by zero");
 
       if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
-	   || code0 == COMPLEX_TYPE)
+	   || code0 == COMPLEX_TYPE || code0 == VECTOR_TYPE)
 	  && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
-	      || code1 == COMPLEX_TYPE))
+	      || code1 == COMPLEX_TYPE || code1 == VECTOR_TYPE))
 	{
 	  if (!(code0 == INTEGER_TYPE && code1 == INTEGER_TYPE))
 	    resultcode = RDIV_EXPR;
@@ -2197,9 +2197,11 @@ build_binary_op (code, orig_op0, orig_op1, convert_p)
 	 but don't convert the args to int!  */
       build_type = integer_type_node;
       if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE
-	   || code0 == COMPLEX_TYPE)
+	   || code0 == COMPLEX_TYPE
+	   || code0 == VECTOR_TYPE)
 	  && (code1 == INTEGER_TYPE || code1 == REAL_TYPE
-	      || code1 == COMPLEX_TYPE))
+	      || code1 == COMPLEX_TYPE
+	      || code1 == VECTOR_TYPE))
 	short_compare = 1;
       else if (code0 == POINTER_TYPE && code1 == POINTER_TYPE)
 	{
@@ -2342,9 +2344,11 @@ build_binary_op (code, orig_op0, orig_op1, convert_p)
       break;
     }
 
-  if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE)
+  if ((code0 == INTEGER_TYPE || code0 == REAL_TYPE || code0 == COMPLEX_TYPE
+       || code0 == VECTOR_TYPE)
       &&
-      (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE))
+      (code1 == INTEGER_TYPE || code1 == REAL_TYPE || code1 == COMPLEX_TYPE
+       || code1 == VECTOR_TYPE))
     {
       int none_complex = (code0 != COMPLEX_TYPE && code1 != COMPLEX_TYPE);
 
@@ -2763,7 +2767,8 @@ build_unary_op (code, xarg, flag)
 
     case NEGATE_EXPR:
       if (!(typecode == INTEGER_TYPE || typecode == REAL_TYPE
-	    || typecode == COMPLEX_TYPE))
+	    || typecode == COMPLEX_TYPE
+	    || typecode == VECTOR_TYPE))
 	{
 	  error ("wrong type argument to unary minus");
 	  return error_mark_node;
@@ -4079,7 +4084,7 @@ convert_for_assignment (type, rhs, errtype, fundecl, funname, parmnum)
   else if ((codel == INTEGER_TYPE || codel == REAL_TYPE 
 	    || codel == ENUMERAL_TYPE || codel == COMPLEX_TYPE
 	    || codel == BOOLEAN_TYPE)
-	   && (coder == INTEGER_TYPE || coder == REAL_TYPE 
+	   && (coder == INTEGER_TYPE || coder == REAL_TYPE
 	       || coder == ENUMERAL_TYPE || coder == COMPLEX_TYPE
 	       || coder == BOOLEAN_TYPE))
     return convert_and_check (type, rhs);

gcc/config/rs6000/rs6000.h

@@ -817,10 +817,11 @@ extern int rs6000_default_long_calls;
    : ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD))
 
 #define ALTIVEC_VECTOR_MODE(MODE)	\
-	((MODE) == V16QImode		\
-	 || (MODE) == V8HImode		\
-	 || (MODE) == V4SFmode		\
-	 || (MODE) == V4SImode)
+        (TARGET_ALTIVEC &&		\
+	 ((MODE) == V16QImode		\
+	  || (MODE) == V8HImode		\
+	  || (MODE) == V4SFmode		\
+	  || (MODE) == V4SImode))
 
 /* Define this macro to be nonzero if the port is prepared to handle
    insns involving vector mode MODE.  At the very least, it must have

gcc/defaults.h

@@ -513,6 +513,10 @@ You Lose!  You must define PREFERRED_DEBUGGING_TYPE!
 #define UNLIKELY_EXECUTED_TEXT_SECTION_NAME "text.unlikely"
 #endif
 
+#ifndef VECTOR_MODE_SUPPORTED_P
+#define VECTOR_MODE_SUPPORTED_P(MODE) 0
+#endif
+
 /* Determine whether __cxa_atexit, rather than atexit, is used to
    register C++ destructors for local statics and global objects. */
 #ifndef DEFAULT_USE_CXA_ATEXIT

gcc/doc/extend.texi

@@ -4373,28 +4373,52 @@ A floating point value, as wide as a SI mode integer, usually 32 bits.
 A floating point value, as wide as a DI mode integer, usually 64 bits.
 @end table
 
-Not all base types or combinations are always valid; which modes can be used
-is determined by the target machine.  For example, if targetting the i386 MMX
-extensions, only @code{V8QI}, @code{V4HI} and @code{V2SI} are allowed modes.
-
 There are no @code{V1xx} vector modes - they would be identical to the
 corresponding base mode.
 
-There is no distinction between signed and unsigned vector modes.  This
-distinction is made by the operations that perform on the vectors, not
-by the data type.
-
-The types defined in this manner are somewhat special, they cannot be
-used with most normal C operations (i.e., a vector addition can @emph{not}
-be represented by a normal addition of two vector type variables).  You
-can declare only variables and use them in function calls and returns, as
-well as in assignments and some casts.  It is possible to cast from one
-vector type to another, provided they are of the same size (in fact, you
-can also cast vectors to and from other datatypes of the same size).
-
-A port that supports vector operations provides a set of built-in functions
-that can be used to operate on vectors.  For example, a function to add two
-vectors and multiply the result by a third could look like this:
+Specifying a combination that is not valid for the current architecture
+will cause gcc to synthesize the instructions using a narrower mode.
+For example, if you specify a variable of type @code{V4SI} and your
+architecture does not allow for this specific SIMD type, gcc will
+produce code that uses 4 @code{SIs}.
+
+The types defined in this manner can be used with a subset of normal C
+operations.  Currently, gcc will allow using the following operators on
+these types: @code{+, -, *, /, unary minus}@.
+
+The operations behave like C++ @code{valarrays}.  Addition is defined as
+the addition of the corresponding elements of the operands.  For
+example, in the code below, each of the 4 elements in @var{a} will be
+added to the corresponding 4 elements in @var{b} and the resulting
+vector will be stored in @var{c}.
+
+@example
+typedef int v4si __attribute__ ((mode(V4SI)));
+
+v4si a, b, c;
+
+c = a + b;
+@end example
+
+Subtraction, multiplication, and division operate in a similar manner.
+Likewise, the result of using the unary minus operator on a vector type
+is a vector whose elements are the negative value of the corresponding
+elements in the operand.
+
+You can declare variables and use them in function calls and returns, as
+well as in assignments and some casts.  You can specify a vector type as
+a return type for a function.  Vector types can also be used as function
+arguments.  It is possible to cast from one vector type to another,
+provided they are of the same size (in fact, you can also cast vectors
+to and from other datatypes of the same size).
+
+You cannot operate between vectors of different lengths or different
+signness without a cast.
+
+A port that supports hardware vector operations, usually provides a set
+of built-in functions that can be used to operate on vectors.  For
+example, a function to add two vectors and multiply the result by a
+third could look like this:
 
 @example
 v4si f (v4si a, v4si b, v4si c)

gcc/emit-rtl.c

@@ -421,7 +421,10 @@ immed_double_const (i0, i1, mode)
     {
       int width;
       if (GET_MODE_CLASS (mode) != MODE_INT
-	  && GET_MODE_CLASS (mode) != MODE_PARTIAL_INT)
+	  && GET_MODE_CLASS (mode) != MODE_PARTIAL_INT
+	  /* We can get a 0 for an error mark.  */
+	  && GET_MODE_CLASS (mode) != MODE_VECTOR_INT
+	  && GET_MODE_CLASS (mode) != MODE_VECTOR_FLOAT)
 	abort ();
 
       /* We clear out all bits that don't belong in MODE, unless they and

gcc/expr.c

@@ -10791,4 +10791,34 @@ try_tablejump (index_type, index_expr, minval, range,
   return 1;
 }
 
+/* Nonzero if the mode is a valid vector mode for this architecture.
+   This returns nonzero even if there is no hardware support for the
+   vector mode, but we can emulate with narrower modes.  */
+
+int
+vector_mode_valid_p (mode)
+     enum machine_mode mode;
+{
+  enum mode_class class = GET_MODE_CLASS (mode);
+  enum machine_mode innermode;
+
+  /* Doh!  What's going on?  */
+  if (class != MODE_VECTOR_INT
+      && class != MODE_VECTOR_FLOAT)
+    return 0;
+
+  /* Hardware support.  Woo hoo!  */
+  if (VECTOR_MODE_SUPPORTED_P (mode))
+    return 1;
+
+  innermode = GET_MODE_INNER (mode);
+
+  /* We should probably return 1 if requesting V4DI and we have no DI,
+     but we have V2DI, but this is probably very unlikely.  */
+
+  /* If we have support for the inner mode, we can safely emulate it.
+     We may not have V2DI, but me can emulate with a pair of DIs.  */
+  return mov_optab->handlers[innermode].insn_code != CODE_FOR_nothing;
+}
+
 #include "gt-expr.h"

gcc/expr.h

@@ -786,3 +786,5 @@ extern void do_jump_by_parts_greater_rtx	PARAMS ((enum machine_mode,
 extern void mark_seen_cases			PARAMS ((tree, unsigned char *,
 							 HOST_WIDE_INT, int));
 #endif
+
+extern int vector_mode_valid_p		PARAMS ((enum machine_mode));

gcc/optabs.c

@@ -120,6 +120,11 @@ static void emit_cmp_and_jump_insn_1 PARAMS ((rtx, rtx, enum machine_mode,
 					    enum rtx_code, int, rtx));
 static void prepare_float_lib_cmp PARAMS ((rtx *, rtx *, enum rtx_code *,
 					 enum machine_mode *, int *));
+static rtx expand_vector_binop PARAMS ((enum machine_mode, optab,
+					rtx, rtx, rtx, int,
+					enum optab_methods));
+static rtx expand_vector_unop PARAMS ((enum machine_mode, optab, rtx, rtx,
+				       int));
 
 /* Add a REG_EQUAL note to the last insn in INSNS.  TARGET is being set to
    the result of operation CODE applied to OP0 (and OP1 if it is a binary
@@ -1531,6 +1536,12 @@ expand_binop (mode, binoptab, op0, op1, target, unsignedp, methods)
       delete_insns_since (last);
     }
 
+  /* Open-code the vector operations if we have no hardware support
+     for them.  */
+  if (class == MODE_VECTOR_INT || class == MODE_VECTOR_FLOAT)
+    return expand_vector_binop (mode, binoptab, op0, op1, target,
+				unsignedp, methods);
+
   /* We need to open-code the complex type operations: '+, -, * and /' */
 
   /* At this point we allow operations between two similar complex
@@ -1900,6 +1911,125 @@ expand_binop (mode, binoptab, op0, op1, target, unsignedp, methods)
   delete_insns_since (entry_last);
   return 0;
 }
+
+/* Like expand_binop, but for open-coding vectors binops.  */
+
+static rtx
+expand_vector_binop (mode, binoptab, op0, op1, target, unsignedp, methods)
+     enum machine_mode mode;
+     optab binoptab;
+     rtx op0, op1;
+     rtx target;
+     int unsignedp;
+     enum optab_methods methods;
+{
+  enum machine_mode submode;
+  int elts, i;
+  rtx t, a, b, res, seq;
+  enum mode_class class;
+
+  class = GET_MODE_CLASS (mode);
+
+  submode = GET_MODE_INNER (mode);
+  elts = GET_MODE_NUNITS (mode);
+
+  if (!target)
+    target = gen_reg_rtx (mode);
+
+  start_sequence ();
+
+  /* FIXME: Optimally, we should try to do this in narrower vector
+     modes if available.  E.g. When trying V8SI, try V4SI, else
+     V2SI, else decay into SI.  */
+
+  switch (binoptab->code)
+    {
+    case PLUS:
+    case MINUS:
+    case MULT:
+    case DIV:
+      for (i = 0; i < elts; ++i)
+	{
+	  t = simplify_gen_subreg (submode, target, mode,
+				   i * UNITS_PER_WORD);
+	  a = simplify_gen_subreg (submode, op0, mode,
+				   i * UNITS_PER_WORD);
+	  b = simplify_gen_subreg (submode, op1, mode,
+				   i * UNITS_PER_WORD);
+
+	  if (binoptab->code == DIV)
+	    {
+	      if (class == MODE_VECTOR_FLOAT)
+		res = expand_binop (submode, binoptab, a, b, t,
+				    unsignedp, methods);
+	      else
+		res = expand_divmod (0, TRUNC_DIV_EXPR, submode,
+				     a, b, t, unsignedp);
+	    }
+	  else
+	    res = expand_binop (submode, binoptab, a, b, t,
+				unsignedp, methods);
+
+	  if (res == 0)
+	    break;
+
+	  emit_move_insn (t, res);
+	}
+      break;
+
+    default:
+      abort ();
+    }
+
+  seq = get_insns ();
+  end_sequence ();
+  emit_insn (seq);
+
+  return target;
+}
+
+/* Like expand_unop but for open-coding vector unops.  */
+
+static rtx
+expand_vector_unop (mode, unoptab, op0, target, unsignedp)
+     enum machine_mode mode;
+     optab unoptab;
+     rtx op0;
+     rtx target;
+     int unsignedp;
+{
+  enum machine_mode submode;
+  int elts, i;
+  rtx t, a, res, seq;
+
+  submode = GET_MODE_INNER (mode);
+  elts = GET_MODE_NUNITS (mode);
+
+  if (!target)
+    target = gen_reg_rtx (mode);
+
+  start_sequence ();
+
+  /* FIXME: Optimally, we should try to do this in narrower vector
+     modes if available.  E.g. When trying V8SI, try V4SI, else
+     V2SI, else decay into SI.  */
+
+  for (i = 0; i < elts; ++i)
+    {
+      t = simplify_gen_subreg (submode, target, mode, i * UNITS_PER_WORD);
+      a = simplify_gen_subreg (submode, op0, mode, i * UNITS_PER_WORD);
+
+      res = expand_unop (submode, unoptab, a, t, unsignedp);
+
+      emit_move_insn (t, res);
+    }
+
+  seq = get_insns ();
+  end_sequence ();
+  emit_insn (seq);
+
+  return target;
+}
 
 /* Expand a binary operator which has both signed and unsigned forms.
    UOPTAB is the optab for unsigned operations, and SOPTAB is for
@@ -2324,6 +2454,9 @@ expand_unop (mode, unoptab, op0, target, unsignedp)
       return target;
     }
 
+  if (class == MODE_VECTOR_FLOAT || class == MODE_VECTOR_INT)
+    return expand_vector_unop (mode, unoptab, op0, target, unsignedp);
+
   /* It can't be done in this mode.  Can we do it in a wider mode?  */
 
   if (class == MODE_INT || class == MODE_FLOAT || class == MODE_COMPLEX_FLOAT)

gcc/simplify-rtx.c

@@ -2268,6 +2268,24 @@ simplify_subreg (outermode, op, innermode, byte)
   if (outermode == innermode && !byte)
     return op;
 
+  /* Simplify subregs of vector constants.  */
+  if (GET_CODE (op) == CONST_VECTOR)
+    {
+      int offset = byte / UNITS_PER_WORD;
+      rtx elt;
+
+      /* This shouldn't happen, but let's not do anything stupid.  */
+      if (GET_MODE_INNER (innermode) != outermode)
+	return NULL_RTX;
+
+      elt = CONST_VECTOR_ELT (op, offset);
+
+      /* ?? We probably don't need this copy_rtx because constants
+	 can be shared.  ?? */
+
+      return copy_rtx (elt);
+    }
+
   /* Attempt to simplify constant to non-SUBREG expression.  */
   if (CONSTANT_P (op))
     {

gcc/testsuite/gcc.c-torture/execute/simd-1.c

+/* Origin: Aldy Hernandez <aldyh@redhat.com>
+
+   Purpose: Test generic SIMD support.  This test should work
+   regardless of if the target has SIMD instructions.
+*/
+
+typedef int __attribute__((mode(V4SI))) vecint;
+
+vecint i = { 150, 100, 150, 200 };
+vecint j = { 10, 13, 20, 30 };
+vecint k;
+
+union {
+  vecint v;
+  int i[4];
+} res;
+
+/* This should go away once we can use == and != on vector types.  */
+void
+verify (int a1, int a2, int a3, int a4,
+	int b1, int b2, int b3, int b4)
+{
+  if (a1 != b1
+      || a2 != b2
+      || a3 != b3
+      || a4 != b4)
+    abort ();
+}
+
+int
+main ()
+{
+  k = i + j;
+  res.v = k;
+
+  verify (res.i[0], res.i[1], res.i[2], res.i[3], 160, 113, 170, 230);
+
+  k = i * j;
+  res.v = k;
+
+  verify (res.i[0], res.i[1], res.i[2], res.i[3], 1500, 1300, 3000, 6000);
+
+  k = i / j;
+  res.v = k;
+
+  verify (res.i[0], res.i[1], res.i[2], res.i[3], 15, 7, 7, 6);
+
+  k = -i;
+  res.v = k;
+  verify (res.i[0], res.i[1], res.i[2], res.i[3],
+	  -150, -100, -150, -200);
+
+  exit (0);
+}

gcc/testsuite/gcc.dg/simd-1.c

+/* { dg-do compile } */
+/* { dg-options "-Wall" } */
+
+/* Origin: Aldy Hernandez <aldyh@redhat.com>.  */
+/* Purpose: Program to test generic SIMD support.  */
+
+typedef int __attribute__((mode(V4SI))) v4si;
+typedef int __attribute__((mode(V8HI))) v8hi;
+typedef int __attribute__((mode(V2SI))) v2si;
+typedef unsigned int __attribute__((mode(V4SI))) uv4si;
+
+v4si a, b;
+v2si c, d;
+v8hi e;
+uv4si f;
+
+int foo __attribute__((mode(DI)));
+int foo1 __attribute__((mode(SI)));
+int foo2 __attribute__((mode(V4HI)));
+
+void
+hanneke ()
+{
+  /* Assignment.  */
+  a = b;
+
+  /* Assignment of different types.  */
+  b = c; /* { dg-error "incompatible types in assignment" } */
+  d = a; /* { dg-error "incompatible types in assignment" } */
+
+  /* Casting between SIMDs of the same size.  */
+  e = (typeof (e)) a;
+
+  /* Different signed SIMD assignment.  */
+  f = a; /* { dg-error "incompatible types in assignment" } */
+
+  /* Casted different signed SIMD assignment.  */
+  f = (uv4si) a;
+
+  /* Assignment between scalar and SIMD of different size.  */
+  foo = a; /* { dg-error "incompatible types in assignment" } */
+
+  /* Casted assignment between scalar and SIMD of same size.  */
+  foo = (typeof (foo)) foo2;
+
+  /* Casted assignment between scalar and SIMD of different size.  */
+  foo1 = (typeof (foo1)) foo2; /* { dg-error "can't convert between vector values of different size" } */
+
+  /* Operators on compatible SIMD types.  */
+  a += b + b;
+  a -= b;
+  a *= b;
+  a /= b;
+  a = -b;
+
+  /* Operators on incompatible SIMD types.  */
+  a = b + c; /* { dg-error "can't convert between vector values of different size" } */
+  a = b - c; /* { dg-error "can't convert between vector values of different size" } */
+  a = b * c; /* { dg-error "can't convert between vector values of different size" } */
+  a = b / c; /* { dg-error "can't convert between vector values of different size" } */
+}