Mesa (master): intel/compiler: properly size attribute wa_flags array for Vulkan

[Iago Toral Quiroga]

Module: Mesa
Branch: master
Commit: 81615ad444ba970d144eeffbe60a7f70adc30b5b
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=81615ad444ba970d144eeffbe60a7f70adc30b5b

Author: Iago Toral Quiroga <itoral at igalia.com>
Date:   Fri Jul 21 10:26:31 2017 +0200

intel/compiler: properly size attribute wa_flags array for Vulkan

Mesa will map user defined vertex input attributes to slots
starting at VERT_ATTRIB_GENERIC0 which gives us room for only 16
slots (up to GL_VERT_ATTRIB_MAX). This sufficient for GL, where
we expose exactly 16 vertex attributes for user defined inputs, but
in Vulkan we can expose up to 28 (which are also mapped from
VERT_ATTRIB_GENERIC0 onwards) so we need to account for this when
we scope the size of the array of attribute workaround flags
that is used during the brw_vertex_workarounds NIR pass. This
prevents out-of-bounds accesses in that array for NIR shaders
that use more than 16 vertex input attributes.

Fixes:
dEQP-VK.pipeline.vertex_input.max_attributes.*

Acked-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>

---

 src/intel/compiler/brw_compiler.h | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/intel/compiler/brw_compiler.h b/src/intel/compiler/brw_compiler.h
index bebd244736..66d6a6f5ee 100644
--- a/src/intel/compiler/brw_compiler.h
+++ b/src/intel/compiler/brw_compiler.h
@@ -188,6 +188,15 @@ struct brw_sampler_prog_key_data {
 #define BRW_ATTRIB_WA_SIGN          32  /* interpret as signed in shader */
 #define BRW_ATTRIB_WA_SCALE         64  /* interpret as scaled in shader */
 
+/**
+ * OpenGL attribute slots fall in [0, VERT_ATTRIB_MAX - 1] with the range
+ * [VERT_ATTRIB_GENERIC0, VERT_ATTRIB_MAX - 1] reserved for up to 16 user
+ * input vertex attributes. In Vulkan, we expose up to 28 user vertex input
+ * attributes that are mapped to slots also starting at VERT_ATTRIB_GENERIC0.
+ */
+#define MAX_GL_VERT_ATTRIB     VERT_ATTRIB_MAX
+#define MAX_VK_VERT_ATTRIB     (VERT_ATTRIB_GENERIC0 + 28)
+
 /** The program key for Vertex Shaders. */
 struct brw_vs_prog_key {
    unsigned program_string_id;
@@ -196,8 +205,15 @@ struct brw_vs_prog_key {
     * Per-attribute workaround flags
     *
     * For each attribute, a combination of BRW_ATTRIB_WA_*.
+    *
+    * For OpenGL, where we expose a maximum of 16 user input atttributes
+    * we only need up to VERT_ATTRIB_MAX slots, however, in Vulkan
+    * slots preceding VERT_ATTRIB_GENERIC0 are unused and we can
+    * expose up to 28 user input vertex attributes that are mapped to slots
+    * starting at VERT_ATTRIB_GENERIC0, so this array needs to be large
+    * enough to hold this many slots.
     */
-   uint8_t gl_attrib_wa_flags[VERT_ATTRIB_MAX];
+   uint8_t gl_attrib_wa_flags[MAX2(MAX_GL_VERT_ATTRIB, MAX_VK_VERT_ATTRIB)];
 
    bool copy_edgeflag:1;