glsl: Extend ir_expression_operation for GLSL 3.00 pack/unpack functions (v2)

For each function {pack,unpack}{Snorm,Unorm,Half}2x16, add a corresponding
opcode to enum ir_expression_operation.  Validate the new opcodes in
ir_validate.cpp.

Also, add opcodes for scalarized variants of the Half2x16 functions.  (The
code generator for the i965 fragment shader requires that all vector
operations be scalarized.  A lowering pass, to be added later, will
scalarize the Half2x16 functions).

v2: Fix assertion message in ir_to_mesa [for idr].

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Matt Tuner <mattst88@gmail.com>
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>

src/glsl/ir_validate.cpp

@@ -329,6 +329,26 @@ ir_validate::visit_leave(ir_expression *ir)
       assert(ir->operands[0]->type == ir->type);
       break;
 
+   case ir_unop_pack_snorm_2x16:
+   case ir_unop_pack_unorm_2x16:
+   case ir_unop_pack_half_2x16:
+      assert(ir->type == glsl_type::uint_type);
+      assert(ir->operands[0]->type == glsl_type::vec2_type);
+      break;
+
+   case ir_unop_unpack_snorm_2x16:
+   case ir_unop_unpack_unorm_2x16:
+   case ir_unop_unpack_half_2x16:
+      assert(ir->type == glsl_type::vec2_type);
+      assert(ir->operands[0]->type == glsl_type::uint_type);
+      break;
+
+   case ir_unop_unpack_half_2x16_split_x:
+   case ir_unop_unpack_half_2x16_split_y:
+      assert(ir->type == glsl_type::float_type);
+      assert(ir->operands[0]->type == glsl_type::uint_type);
+      break;
+
    case ir_unop_noise:
       /* XXX what can we assert here? */
       break;
@@ -423,6 +443,12 @@ ir_validate::visit_leave(ir_expression *ir)
       assert(ir->operands[0]->type == ir->operands[1]->type);
       break;
 
+   case ir_binop_pack_half_2x16_split:
+      assert(ir->type == glsl_type::uint_type);
+      assert(ir->operands[0]->type == glsl_type::float_type);
+      assert(ir->operands[1]->type == glsl_type::float_type);
+      break;
+
    case ir_binop_ubo_load:
       assert(ir->operands[0]->as_constant());
       assert(ir->operands[0]->type == glsl_type::uint_type);