glsl: Add ir_binop_vector_extract

The new opcode is used to get a single field from a vector.  The field
index may not be constant.  This will eventually replace
ir_dereference_array of vectors.  This is similar to the extractelement
instruction in LLVM IR.

http://llvm.org/docs/LangRef.html#extractelement-instruction

v2: Convert tabs to spaces.  Suggested by Eric.

v3: Add array index range checking to ir_binop_vector_extract constant
expression handling.  Suggested by Ken.

v4: Use CLAMP instead of MIN2(MAX2()).  Suggested by Ken.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/glsl/ir_validate.cpp b/src/glsl/ir_validate.cpp
index 26f09c71f63..03480ccd364 100644
--- a/src/glsl/ir_validate.cpp
+++ b/src/glsl/ir_validate.cpp
@@ -487,6 +487,12 @@ ir_validate::visit_leave(ir_expression *ir)
       assert(ir->operands[1]->type == glsl_type::uint_type);
       break;
 
+   case ir_binop_vector_extract:
+      assert(ir->operands[0]->type->is_vector());
+      assert(ir->operands[1]->type->is_scalar()
+             && ir->operands[1]->type->is_integer());
+      break;
+
    case ir_triop_lrp:
       assert(ir->operands[0]->type->base_type == GLSL_TYPE_FLOAT);
       assert(ir->operands[0]->type == ir->operands[1]->type);