glsl: Add a lowering pass for 64-bit integer division

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>

src/compiler/glsl/ir_optimization.h

@@ -53,6 +53,7 @@
 /* Opertaions for lower_64bit_integer_instructions() */
 #define MUL64                     (1U << 0)
 #define SIGN64                    (1U << 1)
+#define DIV64                     (1U << 2)
 
 /**
  * \see class lower_packing_builtins_visitor

src/compiler/glsl/lower_int64.cpp

@@ -368,6 +368,17 @@ lower_64bit_visitor::handle_rvalue(ir_rvalue **rvalue)
       }
       break;
 
+   case ir_binop_div:
+      if (lowering(DIV64)) {
+         if (ir->type->base_type == GLSL_TYPE_UINT64) {
+            *rvalue = handle_op(ir, "__builtin_udiv64", generate_ir::udiv64);
+         } else {
+            *rvalue = handle_op(ir, "__builtin_idiv64", generate_ir::idiv64);
+         }
+         this->progress = true;
+      }
+      break;
+
    case ir_binop_mul:
       if (lowering(MUL64)) {
          *rvalue = handle_op(ir, "__builtin_umul64", generate_ir::umul64);