util: Move util_is_power_of_two to bitscan.h and rename to util_is_power_of_two_or_zero

The new name make the zero-input behavior more obvious.  The next
patch adds a new function with different zero-input behavior.

Signed-off-by: Ian Romanick <[email protected]>
Suggested-by: Matt Turner <[email protected]>
Reviewed-by: Alejandro Piñeiro <[email protected]>

2 files changed, 5 insertions, 5 deletions

diff --git a/src/mesa/state_tracker/st_cb_readpixels.c b/src/mesa/state_tracker/st_cb_readpixels.c
index 84dd2d548e3..29181216071 100644
--- a/src/mesa/state_tracker/st_cb_readpixels.c
+++ b/src/mesa/state_tracker/st_cb_readpixels.c
@@ -270,8 +270,8 @@ blit_to_staging(struct st_context *st, struct st_renderbuffer *strb,
    /* We are creating a texture of the size of the region being read back.
     * Need to check for NPOT texture support. */
    if (!screen->get_param(screen, PIPE_CAP_NPOT_TEXTURES) &&
-       (!util_is_power_of_two(width) ||
-        !util_is_power_of_two(height)))
+       (!util_is_power_of_two_or_zero(width) ||
+        !util_is_power_of_two_or_zero(height)))
       return NULL;
 
    /* create the destination texture */
diff --git a/src/mesa/state_tracker/st_cb_texture.c b/src/mesa/state_tracker/st_cb_texture.c
index 3a793a72654..628e4af1e67 100644
--- a/src/mesa/state_tracker/st_cb_texture.c
+++ b/src/mesa/state_tracker/st_cb_texture.c
@@ -1527,9 +1527,9 @@ st_TexSubImage(struct gl_context *ctx, GLuint dims,
 
    /* Check for NPOT texture support. */
    if (!screen->get_param(screen, PIPE_CAP_NPOT_TEXTURES) &&
-       (!util_is_power_of_two(src_templ.width0) ||
-        !util_is_power_of_two(src_templ.height0) ||
-        !util_is_power_of_two(src_templ.depth0))) {
+       (!util_is_power_of_two_or_zero(src_templ.width0) ||
+        !util_is_power_of_two_or_zero(src_templ.height0) ||
+        !util_is_power_of_two_or_zero(src_templ.depth0))) {
       goto fallback;
    }