diff --git a/src/compiler/glsl/builtin_functions.cpp b/src/compiler/glsl/builtin_functions.cpp
index 67ed936478f..d7473ee4922 100644
--- a/src/compiler/glsl/builtin_functions.cpp
+++ b/src/compiler/glsl/builtin_functions.cpp
@@ -826,6 +826,18 @@ demote_to_helper_invocation(const _mesa_glsl_parse_state *state)
    return state->EXT_demote_to_helper_invocation_enable;
 }
 
+static bool
+is_nir(const _mesa_glsl_parse_state *state)
+{
+   return state->ctx->Const.ShaderCompilerOptions[state->stage].NirOptions;
+}
+
+static bool
+is_not_nir(const _mesa_glsl_parse_state *state)
+{
+   return !is_nir(state);
+}
+
 /** @} */
 
 /******************************************************************************/
@@ -956,6 +968,8 @@ private:
    B1(acos)
    B1(atan2)
    B1(atan)
+   B1(atan2_op)
+   B1(atan_op)
    B1(sinh)
    B1(cosh)
    B1(tanh)
@@ -1729,6 +1743,14 @@ builtin_builder::create_builtins()
                 _atan2(glsl_type::vec2_type),
                 _atan2(glsl_type::vec3_type),
                 _atan2(glsl_type::vec4_type),
+                _atan_op(glsl_type::float_type),
+                _atan_op(glsl_type::vec2_type),
+                _atan_op(glsl_type::vec3_type),
+                _atan_op(glsl_type::vec4_type),
+                _atan2_op(glsl_type::float_type),
+                _atan2_op(glsl_type::vec2_type),
+                _atan2_op(glsl_type::vec3_type),
+                _atan2_op(glsl_type::vec4_type),
                 NULL);
 
    F(sinh)
@@ -4728,7 +4750,7 @@ builtin_builder::_atan2(const glsl_type *type)
    const unsigned n = type->vector_elements;
    ir_variable *y = in_var(type, "y");
    ir_variable *x = in_var(type, "x");
-   MAKE_SIG(type, always_available, 2, y, x);
+   MAKE_SIG(type, is_not_nir, 2, y, x);
 
    /* If we're on the left half-plane rotate the coordinates π/2 clock-wise
     * for the y=0 discontinuity to end up aligned with the vertical
@@ -4865,7 +4887,7 @@ ir_function_signature *
 builtin_builder::_atan(const glsl_type *type)
 {
    ir_variable *y_over_x = in_var(type, "y_over_x");
-   MAKE_SIG(type, always_available, 1, y_over_x);
+   MAKE_SIG(type, is_not_nir, 1, y_over_x);
 
    ir_variable *tmp = body.make_temp(type, "tmp");
    do_atan(body, type, tmp, y_over_x);
@@ -4968,6 +4990,7 @@ UNOP(exp,         ir_unop_exp,  always_available)
 UNOP(log,         ir_unop_log,  always_available)
 UNOP(exp2,        ir_unop_exp2, always_available)
 UNOP(log2,        ir_unop_log2, always_available)
+UNOP(atan_op,     ir_unop_atan, is_nir)
 UNOPA(sqrt,        ir_unop_sqrt)
 UNOPA(inversesqrt, ir_unop_rsq)
 
@@ -5167,6 +5190,12 @@ builtin_builder::_isinf(builtin_available_predicate avail, const glsl_type *type
    return sig;
 }
 
+ir_function_signature *
+builtin_builder::_atan2_op(const glsl_type *x_type)
+{
+   return binop(is_nir, ir_binop_atan2, x_type, x_type, x_type);
+}
+
 ir_function_signature *
 builtin_builder::_floatBitsToInt(const glsl_type *type)
 {