llvmpipe: fix lp_rast_plane alignment on 32bit

Some rasterization code relies (for sse) on the first and third planes
(but not the second for now) being 128bit aligned, and we didn't get that
on 32bit - I mistakenly thought the 64bit number in the struct would get
the thing aligned to 64bit even on 32bit archs.
Stephane Marchesin really figured this out.

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
CC: <mesa-stable@lists.freedesktop.org>

diff --git a/src/gallium/drivers/llvmpipe/lp_rast.h b/src/gallium/drivers/llvmpipe/lp_rast.h
index 34008e1c01ecdb7d76a8ce3532f2c0c07de6f176..d9be7f392ef892fefaf4ca0889fe06b73edd0420 100644 (file)
--- a/src/gallium/drivers/llvmpipe/lp_rast.h
+++ b/src/gallium/drivers/llvmpipe/lp_rast.h
@@ -116,6 +116,12 @@ struct lp_rast_plane {
 
    /* one-pixel sized trivial reject offsets for each plane */
    uint32_t eo;
+   /*
+    * We rely on this struct being 64bit aligned (ideally it would be 128bit
+    * but that's quite the waste) and therefore on 32bit we need padding
+    * since otherwise (even with the 64bit number in there) it wouldn't be.
+    */
+   uint32_t pad;
 };
 
 /**

diff --git a/src/gallium/drivers/llvmpipe/lp_setup_tri.c b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
index 29aee726941ef7c70414801aa105e6b3ae0d457d..98243a12de1b65edfc59441b976ab452d1168df6 100644 (file)
--- a/src/gallium/drivers/llvmpipe/lp_setup_tri.c
+++ b/src/gallium/drivers/llvmpipe/lp_setup_tri.c
@@ -94,6 +94,8 @@ lp_setup_alloc_triangle(struct lp_scene *scene,
    unsigned plane_sz = nr_planes * sizeof(struct lp_rast_plane);
    struct lp_rast_triangle *tri;
 
+   STATIC_ASSERT(sizeof(struct lp_rast_plane) % 8 == 0);
+
    *tri_size = (sizeof(struct lp_rast_triangle) +
                 3 * input_array_sz +
                 plane_sz);