glsl: Refactor get_num_operands.

This adds sentinel values to the ir_expression_operation enum type:
ir_last_unop, ir_last_binop, and ir_last_opcode.  They are set to the
previous one so they don't trigger "unhandled case in switch statement"
warnings, but should never be handled directly.

This allows us to remove the huge array of 1s and 2s in
ir_expression::get_num_operands().

1 files changed, 16 insertions, 1 deletions

diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 38ed2b23efb..3fc834906a3 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -717,6 +717,11 @@ enum ir_expression_operation {
 
    ir_unop_noise,
 
+   /**
+    * A sentinel marking the last of the unary operations.
+    */
+   ir_last_unop = ir_unop_noise,
+
    ir_binop_add,
    ir_binop_sub,
    ir_binop_mul,
@@ -774,7 +779,17 @@ enum ir_expression_operation {
    ir_binop_min,
    ir_binop_max,
 
-   ir_binop_pow
+   ir_binop_pow,
+
+   /**
+    * A sentinel marking the last of the binary operations.
+    */
+   ir_last_binop = ir_binop_pow,
+
+   /**
+    * A sentinel marking the last of all operations.
+    */
+   ir_last_opcode = ir_last_binop
 };
 
 class ir_expression : public ir_rvalue {