gallivm: fix out-of-bounds behavior for fetch/ld

For d3d10 and ARB_robust_buffer_access_behavior, we are required to return
0 for out-of-bounds coordinates (for which we can just enable the code already
there was just disabled). Additionally, also need to return 0 for
out-of-bounds mip level and out-of-bounds layer. This changes the logic
so instead of clamping the level/layer, an out-of-bound mask is computed
instead in this case (actual clamping then can be omitted just like with
coordinates, since we set the fetch offset to zero if that happens anyway).

Reviewed-by: Zack Rusin <[email protected]>

1 files changed, 32 insertions, 6 deletions

diff --git a/src/gallium/auxiliary/gallivm/lp_bld_sample.c b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
index 573a2d00bbf..a0b1d1444de 100644
--- a/src/gallium/auxiliary/gallivm/lp_bld_sample.c
+++ b/src/gallium/auxiliary/gallivm/lp_bld_sample.c
@@ -47,6 +47,7 @@
 #include "lp_bld_logic.h"
 #include "lp_bld_pack.h"
 #include "lp_bld_quad.h"
+#include "lp_bld_bitarit.h"
 
 
 /*
@@ -777,17 +778,19 @@ lp_build_lod_selector(struct lp_build_sample_context *bld,
 
 
 /**
- * For PIPE_TEX_MIPFILTER_NEAREST, convert float LOD to integer
- * mipmap level index.
+ * For PIPE_TEX_MIPFILTER_NEAREST, convert int part of lod
+ * to actual mip level.
  * Note: this is all scalar per quad code.
  * \param lod_ipart  int texture level of detail
- * \param level_out  returns integer 
+ * \param level_out  returns integer
+ * \param out_of_bounds returns per coord out_of_bounds mask if provided
  */
 void
 lp_build_nearest_mip_level(struct lp_build_sample_context *bld,
                            unsigned texture_unit,
                            LLVMValueRef lod_ipart,
-                           LLVMValueRef *level_out)
+                           LLVMValueRef *level_out,
+                           LLVMValueRef *out_of_bounds)
 {
    struct lp_build_context *leveli_bld = &bld->leveli_bld;
    LLVMValueRef first_level, last_level, level;
@@ -801,8 +804,31 @@ lp_build_nearest_mip_level(struct lp_build_sample_context *bld,
 
    level = lp_build_add(leveli_bld, lod_ipart, first_level);
 
-   /* clamp level to legal range of levels */
-   *level_out = lp_build_clamp(leveli_bld, level, first_level, last_level);
+   if (out_of_bounds) {
+      LLVMValueRef out, out1;
+      out = lp_build_cmp(leveli_bld, PIPE_FUNC_LESS, level, first_level);
+      out1 = lp_build_cmp(leveli_bld, PIPE_FUNC_GREATER, level, last_level);
+      out = lp_build_or(leveli_bld, out, out1);
+      if (bld->num_lods == bld->coord_bld.type.length) {
+         *out_of_bounds = out;
+      }
+      else if (bld->num_lods == 1) {
+         *out_of_bounds = lp_build_broadcast_scalar(&bld->int_coord_bld, out);
+      }
+      else {
+         assert(bld->num_lods == bld->coord_bld.type.length / 4);
+         *out_of_bounds = lp_build_unpack_broadcast_aos_scalars(bld->gallivm,
+                                                                leveli_bld->type,
+                                                                bld->int_coord_bld.type,
+                                                                out);
+      }
+      *level_out = level;
+   }
+   else {
+      /* clamp level to legal range of levels */
+      *level_out = lp_build_clamp(leveli_bld, level, first_level, last_level);
+
+   }
 }