amd: lower load_frag_coord in NIR

Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32782>

src/amd/common/ac_nir.c

@@ -174,6 +174,12 @@ lower_intrinsic_to_arg(nir_builder *b, nir_instr *instr, void *state)
    case nir_intrinsic_load_pixel_coord:
       replacement = nir_unpack_32_2x16(b, ac_nir_load_arg(b, s->args, s->args->pos_fixed_pt));
       break;
+   case nir_intrinsic_load_frag_coord:
+      replacement = nir_vec4(b, ac_nir_load_arg(b, s->args, s->args->frag_pos[0]),
+                             ac_nir_load_arg(b, s->args, s->args->frag_pos[1]),
+                             ac_nir_load_arg(b, s->args, s->args->frag_pos[2]),
+                             ac_nir_load_arg(b, s->args, s->args->frag_pos[3]));
+      break;
    default:
       return false;
    }

src/amd/compiler/aco_instruction_selection.cpp

@@ -5527,29 +5527,6 @@ emit_interp_mov_instr(isel_context* ctx, unsigned idx, unsigned component, unsig
       emit_extract_vector(ctx, tmp, high_16bits, dst);
 }
 
-void
-emit_load_frag_coord(isel_context* ctx, Temp dst, unsigned num_components)
-{
-   Builder bld(ctx->program, ctx->block);
-
-   aco_ptr<Instruction> vec(
-      create_instruction(aco_opcode::p_create_vector, Format::PSEUDO, num_components, 1));
-   for (unsigned i = 0; i < num_components; i++) {
-      if (ctx->args->frag_pos[i].used)
-         vec->operands[i] = Operand(get_arg(ctx, ctx->args->frag_pos[i]));
-      else
-         vec->operands[i] = Operand(v1);
-   }
-
-   for (Operand& op : vec->operands)
-      op = op.isUndefined() ? Operand::zero() : op;
-
-   vec->definitions[0] = Definition(dst);
-   ctx->block->instructions.emplace_back(std::move(vec));
-   emit_split_vector(ctx, dst, num_components);
-   return;
-}
-
 void
 emit_load_frag_shading_rate(isel_context* ctx, Temp dst)
 {
@@ -8154,10 +8131,6 @@ visit_intrinsic(isel_context* ctx, nir_intrinsic_instr* instr)
       bld.copy(Definition(dst), Operand(get_arg(ctx, ctx->args->view_index)));
       break;
    }
-   case nir_intrinsic_load_frag_coord: {
-      emit_load_frag_coord(ctx, get_ssa_temp(ctx, &instr->def), 4);
-      break;
-   }
    case nir_intrinsic_load_frag_shading_rate:
       emit_load_frag_shading_rate(ctx, get_ssa_temp(ctx, &instr->def));
       break;

src/amd/compiler/aco_instruction_selection_setup.cpp

@@ -560,7 +560,6 @@ init_context(isel_context* ctx, nir_shader* shader)
                case nir_intrinsic_load_barycentric_at_offset:
                case nir_intrinsic_load_interpolated_input:
                case nir_intrinsic_load_front_face_fsign:
-               case nir_intrinsic_load_frag_coord:
                case nir_intrinsic_load_frag_shading_rate:
                case nir_intrinsic_load_sample_pos:
                case nir_intrinsic_load_local_invocation_id:

src/amd/llvm/ac_nir_to_llvm.c

@@ -2873,16 +2873,6 @@ emit_load_frag_shading_rate(struct ac_nir_context *ctx)
    return LLVMBuildOr(ctx->ac.builder, x_rate, y_rate, "");
 }
 
-static LLVMValueRef
-emit_load_frag_coord(struct ac_nir_context *ctx)
-{
-   LLVMValueRef values[4] = {
-      ac_get_arg(&ctx->ac, ctx->args->frag_pos[0]), ac_get_arg(&ctx->ac, ctx->args->frag_pos[1]),
-      ac_get_arg(&ctx->ac, ctx->args->frag_pos[2]), ac_get_arg(&ctx->ac, ctx->args->frag_pos[3])};
-
-   return ac_to_integer(&ctx->ac, ac_build_gather_values(&ctx->ac, values, 4));
-}
-
 static bool visit_intrinsic(struct ac_nir_context *ctx, nir_intrinsic_instr *instr)
 {
    LLVMValueRef result = NULL;
@@ -3024,9 +3014,6 @@ static bool visit_intrinsic(struct ac_nir_context *ctx, nir_intrinsic_instr *ins
    case nir_intrinsic_load_sample_pos:
       result = load_sample_pos(ctx);
       break;
-   case nir_intrinsic_load_frag_coord:
-      result = emit_load_frag_coord(ctx);
-      break;
    case nir_intrinsic_load_frag_shading_rate:
       result = emit_load_frag_shading_rate(ctx);
       break;