[Mesa-dev] [PATCH 05/10] nir: Use well-known power-of-two test instead of util_bitscan

[Ian Romanick]

From: Ian Romanick <ian.d.romanick at intel.com>

This prevents the next change from breaking the build, and I felt that
it was different enough from the rest of that patch to stand on its own.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
---
 src/compiler/nir/nir_validate.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/compiler/nir/nir_validate.c b/src/compiler/nir/nir_validate.c
index 9bf8c70..ca191d2 100644
--- a/src/compiler/nir/nir_validate.c
+++ b/src/compiler/nir/nir_validate.c
@@ -979,8 +979,9 @@ validate_var_decl(nir_variable *var, bool is_global, validate_state *state)
 
    validate_assert(state, is_global == nir_variable_is_global(var));
 
-   /* Must have exactly one mode set */
-   validate_assert(state, util_bitcount(var->data.mode) == 1);
+   /* Must have exactly one mode set (i.e., is a power of two) */
+   validate_assert(state, (var->data.mode != 0 &&
+                           !(var->data.mode & (var->data.mode - 1))));
 
    if (var->data.compact) {
       /* The "compact" flag is only valid on arrays of scalars. */
-- 
2.9.5