Add COMPLEX_VECTOR_INT modes for amdgcn

This enables only minimal support for complex types containing integer
vectors with the intention of allowing vectorized divmod libfunc operations
(these return a pair of integers modelled as a complex number).

There's no way to declare variables of this mode in the front-end, and no
attempt to support it everywhere that complex modes can exist; the only
use-case, at present, is the implicit use by divmod calls generated by
the middle-end.

In order to prevent unexpected problems with other architectures these
modes are only enabled for amdgcn.

gcc/ChangeLog:

	* config/gcn/gcn-modes.def: Initialize COMPLEX_VECTOR_INT modes.
	* genmodes.cc (complex_class): Support MODE_COMPLEX_VECTOR_INT.
	(complete_mode): Likewise.
	(emit_mode_unit_size): Upgrade mode_unit_size type to short.
	(emit_mode_adjustments): Support MODE_COMPLEX_VECTOR_INT.
	* machmode.def: Mention MODE_COMPLEX_VECTOR_INT.
	* machmode.h (mode_to_unit_size): Upgrade type to short.
	* mode-classes.def: Add MODE_COMPLEX_VECTOR_INT.
	* stor-layout.cc (int_mode_for_mode): Support MODE_COMPLEX_VECTOR_INT.
	* tree.cc (build_complex_type): Allow VECTOR_INTEGER_TYPE_P.

diff --git a/gcc/config/gcn/gcn-modes.def b/gcc/config/gcn/gcn-modes.def
index 1357bec825d..486168fbeb3 100644
--- a/gcc/config/gcn/gcn-modes.def
+++ b/gcc/config/gcn/gcn-modes.def
@@ -121,3 +121,6 @@ ADJUST_ALIGNMENT (V2TI, 16);
 ADJUST_ALIGNMENT (V2HF, 2);
 ADJUST_ALIGNMENT (V2SF, 4);
 ADJUST_ALIGNMENT (V2DF, 8);
+
+/* These are used for vectorized divmod.  */
+COMPLEX_MODES (VECTOR_INT);
diff --git a/gcc/genmodes.cc b/gcc/genmodes.cc
index 715787b8f48..d472ee5a9a3 100644
--- a/gcc/genmodes.cc
+++ b/gcc/genmodes.cc
@@ -125,6 +125,7 @@ complex_class (enum mode_class c)
     case MODE_INT: return MODE_COMPLEX_INT;
     case MODE_PARTIAL_INT: return MODE_COMPLEX_INT;
     case MODE_FLOAT: return MODE_COMPLEX_FLOAT;
+    case MODE_VECTOR_INT: return MODE_COMPLEX_VECTOR_INT;
     default:
       error ("no complex class for class %s", mode_class_names[c]);
       return MODE_RANDOM;
@@ -382,6 +383,7 @@ complete_mode (struct mode_data *m)
 
     case MODE_COMPLEX_INT:
     case MODE_COMPLEX_FLOAT:
+    case MODE_COMPLEX_VECTOR_INT:
       /* Complex modes should have a component indicated, but no more.  */
       validate_mode (m, UNSET, UNSET, SET, UNSET, UNSET);
       m->ncomponents = 2;
@@ -1173,10 +1175,10 @@ inline __attribute__((__always_inline__))\n\
 #else\n\
 extern __inline__ __attribute__((__always_inline__, __gnu_inline__))\n\
 #endif\n\
-unsigned char\n\
+unsigned short\n\
 mode_unit_size_inline (machine_mode mode)\n\
 {\n\
-  extern CONST_MODE_UNIT_SIZE unsigned char mode_unit_size[NUM_MACHINE_MODES];\
+  extern CONST_MODE_UNIT_SIZE unsigned short mode_unit_size[NUM_MACHINE_MODES];\
 \n\
   gcc_assert (mode >= 0 && mode < NUM_MACHINE_MODES);\n\
   switch (mode)\n\
@@ -1683,7 +1685,7 @@ emit_mode_unit_size (void)
   int c;
   struct mode_data *m;
 
-  print_maybe_const_decl ("%sunsigned char", "mode_unit_size",
+  print_maybe_const_decl ("%sunsigned short", "mode_unit_size",
 			  "NUM_MACHINE_MODES", adj_bytesize);
 
   for_all_modes (c, m)
@@ -1873,6 +1875,7 @@ emit_mode_adjustments (void)
 	    {
 	    case MODE_COMPLEX_INT:
 	    case MODE_COMPLEX_FLOAT:
+            case MODE_COMPLEX_VECTOR_INT:
 	      printf ("  mode_size[E_%smode] = 2*s;\n", m->name);
 	      printf ("  mode_unit_size[E_%smode] = s;\n", m->name);
 	      printf ("  mode_base_align[E_%smode] = s & (~s + 1);\n",
@@ -1920,6 +1923,7 @@ emit_mode_adjustments (void)
 	    {
 	    case MODE_COMPLEX_INT:
 	    case MODE_COMPLEX_FLOAT:
+	    case MODE_COMPLEX_VECTOR_INT:
 	      printf ("  mode_base_align[E_%smode] = s;\n", m->name);
 	      break;
 
diff --git a/gcc/machmode.def b/gcc/machmode.def
index 62e2ba10d45..5bb5ae14fc3 100644
--- a/gcc/machmode.def
+++ b/gcc/machmode.def
@@ -267,6 +267,7 @@ UACCUM_MODE (UTA, 16, 64, 64); /* 64.64 */
 COMPLEX_MODES (INT);
 COMPLEX_MODES (PARTIAL_INT);
 COMPLEX_MODES (FLOAT);
+/* COMPLEX_MODES (VECTOR_INT);  Let's enable these per architecture.  */
 
 /* Decimal floating point modes.  */
 DECIMAL_FLOAT_MODE (SD, 4, decimal_single_format);
diff --git a/gcc/machmode.h b/gcc/machmode.h
index f1865c1ef42..5f4e13f0643 100644
--- a/gcc/machmode.h
+++ b/gcc/machmode.h
@@ -26,7 +26,7 @@ extern CONST_MODE_SIZE poly_uint16_pod mode_size[NUM_MACHINE_MODES];
 extern CONST_MODE_PRECISION poly_uint16_pod mode_precision[NUM_MACHINE_MODES];
 extern const unsigned char mode_inner[NUM_MACHINE_MODES];
 extern CONST_MODE_NUNITS poly_uint16_pod mode_nunits[NUM_MACHINE_MODES];
-extern CONST_MODE_UNIT_SIZE unsigned char mode_unit_size[NUM_MACHINE_MODES];
+extern CONST_MODE_UNIT_SIZE unsigned short mode_unit_size[NUM_MACHINE_MODES];
 extern const unsigned short mode_unit_precision[NUM_MACHINE_MODES];
 extern const unsigned char mode_next[NUM_MACHINE_MODES];
 extern const unsigned char mode_wider[NUM_MACHINE_MODES];
@@ -586,7 +586,7 @@ mode_to_inner (machine_mode mode)
 
 /* Return the base GET_MODE_UNIT_SIZE value for MODE.  */
 
-ALWAYS_INLINE unsigned char
+ALWAYS_INLINE unsigned short
 mode_to_unit_size (machine_mode mode)
 {
 #if GCC_VERSION >= 4001
diff --git a/gcc/mode-classes.def b/gcc/mode-classes.def
index de42d7ee6fb..dc6097081b3 100644
--- a/gcc/mode-classes.def
+++ b/gcc/mode-classes.def
@@ -37,4 +37,5 @@ along with GCC; see the file COPYING3.  If not see
   DEF_MODE_CLASS (MODE_VECTOR_ACCUM),	/* SIMD vectors */		   \
   DEF_MODE_CLASS (MODE_VECTOR_UACCUM),	/* SIMD vectors */		   \
   DEF_MODE_CLASS (MODE_VECTOR_FLOAT),                                      \
+  DEF_MODE_CLASS (MODE_COMPLEX_VECTOR_INT),				   \
   DEF_MODE_CLASS (MODE_OPAQUE)          /* opaque modes */
diff --git a/gcc/stor-layout.cc b/gcc/stor-layout.cc
index 023de8c37db..0699d44e516 100644
--- a/gcc/stor-layout.cc
+++ b/gcc/stor-layout.cc
@@ -391,6 +391,7 @@ int_mode_for_mode (machine_mode mode)
     case MODE_VECTOR_ACCUM:
     case MODE_VECTOR_UFRACT:
     case MODE_VECTOR_UACCUM:
+    case MODE_COMPLEX_VECTOR_INT:
       return int_mode_for_size (GET_MODE_BITSIZE (mode), 0);
 
     case MODE_OPAQUE:
diff --git a/gcc/tree.cc b/gcc/tree.cc
index ead4248b8e5..e1c87bbb0bb 100644
--- a/gcc/tree.cc
+++ b/gcc/tree.cc
@@ -7665,7 +7665,8 @@ build_complex_type (tree component_type, bool named)
 {
   gcc_assert (INTEGRAL_TYPE_P (component_type)
 	      || SCALAR_FLOAT_TYPE_P (component_type)
-	      || FIXED_POINT_TYPE_P (component_type));
+	      || FIXED_POINT_TYPE_P (component_type)
+	      || VECTOR_INTEGER_TYPE_P (component_type));
 
   /* Make a node of the sort we want.  */
   tree probe = make_node (COMPLEX_TYPE);