[Mesa-dev] [PATCH] radv/gfx9: add a workaround for viewing a slice of 3D as a 2D image

[Samuel Pitoiset]

Ported from RadeonSI.

That doesn't fix anything known but I think we need it.

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 src/amd/common/ac_nir_to_llvm.c | 45 +++++++++++++++++++++++++++++++++--------
 1 file changed, 37 insertions(+), 8 deletions(-)

diff --git a/src/amd/common/ac_nir_to_llvm.c b/src/amd/common/ac_nir_to_llvm.c
index 2c5a6e6cf6..06d1b31047 100644
--- a/src/amd/common/ac_nir_to_llvm.c
+++ b/src/amd/common/ac_nir_to_llvm.c
@@ -3524,7 +3524,8 @@ static LLVMValueRef adjust_sample_index_using_fmask(struct ac_llvm_context *ctx,
 }
 
 static LLVMValueRef get_image_coords(struct ac_nir_context *ctx,
-				     const nir_intrinsic_instr *instr)
+				     const nir_intrinsic_instr *instr,
+				     LLVMValueRef desc)
 {
 	const struct glsl_type *type = glsl_without_array(instr->variables[0]->var->type);
 
@@ -3599,6 +3600,23 @@ static LLVMValueRef get_image_coords(struct ac_nir_context *ctx,
 			} else
 				coords[1] = ctx->ac.i32_0;
 			count++;
+		} else 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, desc, const5, "");
+			first_layer = LLVMBuildAnd(ctx->ac.builder, first_layer, mask, "");
+
+			coords[2] = first_layer;
+			count++;
 		}
 
 		if (is_ms) {
@@ -3650,9 +3668,13 @@ static LLVMValueRef visit_image_load(struct ac_nir_context *ctx,
 	} else {
 		LLVMValueRef da = glsl_is_array_image(type) ? ctx->ac.i1true : ctx->ac.i1false;
 		LLVMValueRef slc = ctx->ac.i1false;
+		LLVMValueRef desc;
+
+		desc = get_sampler_desc(ctx, instr->variables[0], AC_DESC_IMAGE,
+					NULL, true, false);
 
-		params[0] = get_image_coords(ctx, instr);
-		params[1] = get_sampler_desc(ctx, instr->variables[0], AC_DESC_IMAGE, NULL, true, false);
+		params[0] = get_image_coords(ctx, instr, desc);
+		params[1] = desc;
 		params[2] = LLVMConstInt(ctx->ac.i32, 15, false); /* dmask */
 		params[3] = (var->data.image._volatile || var->data.image.coherent) ?
 			    ctx->ac.i1true : ctx->ac.i1false;
@@ -3698,10 +3720,14 @@ static void visit_image_store(struct ac_nir_context *ctx,
 	} else {
 		LLVMValueRef da = glsl_is_array_image(type) ? ctx->ac.i1true : ctx->ac.i1false;
 		LLVMValueRef slc = ctx->ac.i1false;
+		LLVMValueRef desc;
+
+		desc = get_sampler_desc(ctx, instr->variables[0], AC_DESC_IMAGE,
+					NULL, true, true);
 
 		params[0] = ac_to_float(&ctx->ac, get_src(ctx, instr->src[2]));
-		params[1] = get_image_coords(ctx, instr); /* coords */
-		params[2] = get_sampler_desc(ctx, instr->variables[0], AC_DESC_IMAGE, NULL, true, true);
+		params[1] = get_image_coords(ctx, instr, desc);
+		params[2] = desc;
 		params[3] = LLVMConstInt(ctx->ac.i32, 15, false); /* dmask */
 		params[4] = (force_glc || var->data.image._volatile || var->data.image.coherent) ?
 			    ctx->ac.i1true : ctx->ac.i1false;
@@ -3780,10 +3806,13 @@ static LLVMValueRef visit_image_atomic(struct ac_nir_context *ctx,
 				  "llvm.amdgcn.buffer.atomic.%s", atomic_name);
 	} else {
 		char coords_type[8];
+		LLVMValueRef desc;
 
-		LLVMValueRef coords = params[param_count++] = get_image_coords(ctx, instr);
-		params[param_count++] = get_sampler_desc(ctx, instr->variables[0], AC_DESC_IMAGE,
-							 NULL, true, true);
+		desc = get_sampler_desc(ctx, instr->variables[0], AC_DESC_IMAGE,
+					NULL, true, true);
+
+		LLVMValueRef coords = params[param_count++] = get_image_coords(ctx, instr, desc);
+		params[param_count++] = desc;
 		params[param_count++] = ctx->ac.i1false; /* r128 */
 		params[param_count++] = glsl_is_array_image(type) ? ctx->ac.i1true : ctx->ac.i1false;      /* da */
 		params[param_count++] = ctx->ac.i1false;  /* slc */
-- 
2.16.2