ac/nir: add a workaround for viewing a slice of 3D as a 2D image

GL and Vulkan allow you to bind a single layer of a 3D texture to a 2D
image, and we weren't implementing a workaround for that on gfx9 that
TGSI was. Copy it over.

Fixes KHR-GL45.shader_image_load_store.non-layered_binding with radeonsi
NIR.

Reviewed-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index 0878017..e71c8f1 100644 (file)
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -114,9 +114,19 @@ get_ac_image_dim(const struct ac_llvm_context *ctx, enum glsl_sampler_dim sdim,
 {
        enum ac_image_dim dim = get_ac_sampler_dim(ctx, sdim, is_array);
 
+       /* Match the resource type set in the descriptor. */
        if (dim == ac_image_cube ||
            (ctx->chip_class <= GFX8 && dim == ac_image_3d))
                dim = ac_image_2darray;
+       else if (sdim == GLSL_SAMPLER_DIM_2D && !is_array && ctx->chip_class == GFX9) {
+               /* When a single layer of a 3D texture is bound, the shader
+                * will refer to a 2D target, but the descriptor has a 3D type.
+                * Since the HW ignores BASE_ARRAY in this case, we need to
+                * send 3 coordinates. This doesn't hurt when the underlying
+                * texture is non-3D.
+                */
+               dim = ac_image_3d;
+       }
 
        return dim;
 }
@@ -2461,6 +2471,25 @@ static void get_image_coords(struct ac_nir_context *ctx,
                                args->coords[1] = ctx->ac.i32_0;
                        count++;
                }
+               if (ctx->ac.chip_class == GFX9 &&
+                   dim == GLSL_SAMPLER_DIM_2D &&
+                   !is_array) {
+                       /* The hw can't bind a slice of a 3D image as a 2D
+                        * image, because it ignores BASE_ARRAY if the target
+                        * is 3D. The workaround is to read BASE_ARRAY and set
+                        * it as the 3rd address operand for all 2D images.
+                        */
+                       LLVMValueRef first_layer, const5, mask;
+
+                       const5 = LLVMConstInt(ctx->ac.i32, 5, 0);
+                       mask = LLVMConstInt(ctx->ac.i32, S_008F24_BASE_ARRAY(~0), 0);
+                       first_layer = LLVMBuildExtractElement(ctx->ac.builder, args->resource, const5, "");
+                       first_layer = LLVMBuildAnd(ctx->ac.builder, first_layer, mask, "");
+
+                       args->coords[count] = first_layer;
+                       count++;
+               }
+
 
                if (is_ms) {
                        args->coords[count] = sample_index;
@@ -2535,8 +2564,8 @@ static LLVMValueRef visit_image_load(struct ac_nir_context *ctx,
                res = ac_to_integer(&ctx->ac, res);
        } else {
                args.opcode = ac_image_load;
-               get_image_coords(ctx, instr, &args, dim, is_array);
                args.resource = get_image_descriptor(ctx, instr, AC_DESC_IMAGE, false);
+               get_image_coords(ctx, instr, &args, dim, is_array);
                args.dim = get_ac_image_dim(&ctx->ac, dim, is_array);
                args.dmask = 15;
                args.attributes = AC_FUNC_ATTR_READONLY;
@@ -2592,8 +2621,8 @@ static void visit_image_store(struct ac_nir_context *ctx,
        } else {
                args.opcode = ac_image_store;
                args.data[0] = ac_to_float(&ctx->ac, get_src(ctx, instr->src[3]));
-               get_image_coords(ctx, instr, &args, dim, is_array);
                args.resource = get_image_descriptor(ctx, instr, AC_DESC_IMAGE, true);
+               get_image_coords(ctx, instr, &args, dim, is_array);
                args.dim = get_ac_image_dim(&ctx->ac, dim, is_array);
                args.dmask = 15;
 
@@ -2745,8 +2774,8 @@ static LLVMValueRef visit_image_atomic(struct ac_nir_context *ctx,
                args.data[0] = params[0];
                if (cmpswap)
                        args.data[1] = params[1];
-               get_image_coords(ctx, instr, &args, dim, is_array);
                args.resource = get_image_descriptor(ctx, instr, AC_DESC_IMAGE, true);
+               get_image_coords(ctx, instr, &args, dim, is_array);
                args.dim = get_ac_image_dim(&ctx->ac, dim, is_array);
 
                return ac_build_image_opcode(&ctx->ac, &args);