glsl: Add ir_binop_carry and ir_binop_borrow.

Calculates the carry out of the addition of two values and the
borrow from subtraction respectively. Will be used in uaddCarry() and
usubBorrow() built-in implementations.

Reviewed-by: Kenneth Graunke <[email protected]>
Reviewed-by: Ian Romanick <[email protected]>

5 files changed, 38 insertions, 0 deletions

diff --git a/src/glsl/ir.cpp b/src/glsl/ir.cpp
index ae67d6bddec..149ddbd5342 100644
--- a/src/glsl/ir.cpp
+++ b/src/glsl/ir.cpp
@@ -398,6 +398,8 @@ ir_expression::ir_expression(int op, ir_rvalue *op0, ir_rvalue *op1)
       this->type = glsl_type::uint_type;
       break;
 
+   case ir_binop_carry:
+   case ir_binop_borrow:
    case ir_binop_lshift:
    case ir_binop_rshift:
    case ir_binop_bfm:
@@ -528,6 +530,8 @@ static const char *const operator_strs[] = {
    "-",
    "*",
    "/",
+   "carry",
+   "borrow",
    "%",
    "<",
    ">",
diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index 1a4a3a2e36b..756ce9c7cd3 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -1095,6 +1095,21 @@ enum ir_expression_operation {
    ir_binop_div,
 
    /**
+    * Returns the carry resulting from the addition of the two arguments.
+    */
+   /*@{*/
+   ir_binop_carry,
+   /*@}*/
+
+   /**
+    * Returns the borrow resulting from the subtraction of the second argument
+    * from the first argument.
+    */
+   /*@{*/
+   ir_binop_borrow,
+   /*@}*/
+
+   /**
     * Takes one of two combinations of arguments:
     *
     * - mod(vecN, vecN)
diff --git a/src/glsl/ir_builder.cpp b/src/glsl/ir_builder.cpp
index 98b43229508..b6ce889834c 100644
--- a/src/glsl/ir_builder.cpp
+++ b/src/glsl/ir_builder.cpp
@@ -221,6 +221,16 @@ ir_expression *div(operand a, operand b)
    return expr(ir_binop_div, a, b);
 }
 
+ir_expression *carry(operand a, operand b)
+{
+   return expr(ir_binop_carry, a, b);
+}
+
+ir_expression *borrow(operand a, operand b)
+{
+   return expr(ir_binop_borrow, a, b);
+}
+
 ir_expression *round_even(operand a)
 {
    return expr(ir_unop_round_even, a);
diff --git a/src/glsl/ir_builder.h b/src/glsl/ir_builder.h
index 6a5f771193b..1345788ab13 100644
--- a/src/glsl/ir_builder.h
+++ b/src/glsl/ir_builder.h
@@ -134,6 +134,8 @@ ir_expression *add(operand a, operand b);
 ir_expression *sub(operand a, operand b);
 ir_expression *mul(operand a, operand b);
 ir_expression *div(operand a, operand b);
+ir_expression *carry(operand a, operand b);
+ir_expression *borrow(operand a, operand b);
 ir_expression *round_even(operand a);
 ir_expression *dot(operand a, operand b);
 ir_expression *dotlike(operand a, operand b);
diff --git a/src/glsl/ir_validate.cpp b/src/glsl/ir_validate.cpp
index 2c64f4e582a..38db8c20677 100644
--- a/src/glsl/ir_validate.cpp
+++ b/src/glsl/ir_validate.cpp
@@ -429,6 +429,13 @@ ir_validate::visit_leave(ir_expression *ir)
       }
       break;
 
+   case ir_binop_carry:
+   case ir_binop_borrow:
+      assert(ir->type == ir->operands[0]->type);
+      assert(ir->type == ir->operands[1]->type);
+      assert(ir->type->base_type == GLSL_TYPE_UINT);
+      break;
+
    case ir_binop_less:
    case ir_binop_greater:
    case ir_binop_lequal: