i965/fs: Use the LRP instruction for ir_triop_lrp when possible.

v2 [mattst88]:
   - Add BRW_OPCODE_LRP to list of CSE-able expressions.
   - Fix op_var[] array size.
   - Rename arguments to emit_lrp to (x, y, a) to clear confusion.
   - Add LRP function to brw_fs.cpp/.h.
   - Corrected comment about LRP instruction arguments in emit_lrp.
v3 [mattst88]:
   - Duplicate MAD code for LRP instead of using a function pointer.
   - Check for != GRF instead of == IMM in emit_lrp.
   - Lower LRP on gen < 6.

Reviewed-by: Matt Turner <mattst88@gmail.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>

1

1 files changed, 15 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs_channel_expressions.cpp b/src/mesa/drivers/dri/i965/brw_fs_channel_expressions.cpp
index ea06225..30d8d9b 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_channel_expressions.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_channel_expressions.cpp
@@ -135,7 +135,7 @@ ir_channel_expressions_visitor::visit_leave(ir_assignment *ir)
    ir_expression *expr = ir->rhs->as_expression();
    bool found_vector = false;
    unsigned int i, vector_elements = 1;
-   ir_variable *op_var[2];
+   ir_variable *op_var[3];
 
    if (!expr)
       return visit_continue;
@@ -342,6 +342,20 @@ ir_channel_expressions_visitor::visit_leave(ir_assignment *ir)
       assert(!"not yet supported");
       break;
 
+   case ir_triop_lrp:
+      for (i = 0; i < vector_elements; i++) {
+	 ir_rvalue *op0 = get_element(op_var[0], i);
+	 ir_rvalue *op1 = get_element(op_var[1], i);
+	 ir_rvalue *op2 = get_element(op_var[2], i);
+
+	 assign(ir, i, new(mem_ctx) ir_expression(expr->operation,
+						  element_type,
+						  op0,
+						  op1,
+						  op2));
+      }
+      break;
+
    case ir_unop_pack_snorm_2x16:
    case ir_unop_pack_snorm_4x8:
    case ir_unop_pack_unorm_2x16: