[Mesa-dev] [RFC PATCH V3 09/10] i965/fs: add new helper function for emitting interpolateAt* exprs

[Chris Forbes]

The implementation is going to be nontrivial, so let's get it out of
visit().

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
---
 src/mesa/drivers/dri/i965/brw_fs.h           |  1 +
 src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 29 ++++++++++++++++++++++++++--
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index c45faea..401f273 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -369,6 +369,7 @@ public:
                     fs_reg src0, fs_reg src1);
    bool try_emit_saturate(ir_expression *ir);
    bool try_emit_mad(ir_expression *ir, int mul_arg);
+   void emit_interpolate_expression(ir_expression *ir);
    void try_replace_with_sel();
    void emit_bool_to_cond_code(ir_rvalue *condition);
    void emit_if_gen6(ir_if *ir);
diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
index 9eb9a9d..538f1b3 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp
@@ -326,6 +326,12 @@ fs_visitor::try_emit_mad(ir_expression *ir, int mul_arg)
 }
 
 void
+fs_visitor::emit_interpolate_expression(ir_expression *ir)
+{
+   this->result = fs_reg(this, ir->type);
+}
+
+void
 fs_visitor::visit(ir_expression *ir)
 {
    unsigned int operand;
@@ -336,9 +342,22 @@ fs_visitor::visit(ir_expression *ir)
 
    if (try_emit_saturate(ir))
       return;
-   if (ir->operation == ir_binop_add) {
+
+   /* Deal with the real oddball stuff first */
+   switch (ir->operation) {
+   case ir_binop_add:
       if (try_emit_mad(ir, 0) || try_emit_mad(ir, 1))
-	 return;
+         return;
+      break;
+
+   case ir_unop_interpolate_at_centroid:
+   case ir_binop_interpolate_at_offset:
+   case ir_binop_interpolate_at_sample:
+      emit_interpolate_expression(ir);
+      return;
+
+   default:
+      break;
    }
 
    for (operand = 0; operand < ir->get_num_operands(); operand++) {
@@ -781,6 +800,12 @@ fs_visitor::visit(ir_expression *ir)
       inst = emit(BRW_OPCODE_SEL, this->result, op[1], op[2]);
       inst->predicate = BRW_PREDICATE_NORMAL;
       break;
+
+   case ir_unop_interpolate_at_centroid:
+   case ir_binop_interpolate_at_offset:
+   case ir_binop_interpolate_at_sample:
+      assert(!"not reached; already handled above");
+      break;
    }
 }
 
-- 
1.8.4.2