-/* Reads RGBA8888 value from the tilebuffer and converts to a RGBA32F register,
- * using scalar ops functional on earlier Midgard generations. Newer Midgard
- * generations have faster vectorized reads. This operation is for blend
- * shaders in particular; reading the tilebuffer from the fragment shader
- * remains an open problem. */
-
-static void
-emit_fb_read_blend_scalar(compiler_context *ctx, unsigned reg)
-{
- midgard_instruction ins = m_ld_color_buffer_8(reg, 0);
- ins.load_store.swizzle = 0; /* xxxx */
-
- /* Read each component sequentially */
-
- for (unsigned c = 0; c < 4; ++c) {
- ins.load_store.mask = (1 << c);
- ins.load_store.unknown = c;
- emit_mir_instruction(ctx, ins);
- }
-
- /* vadd.u2f hr2, zext(hr2), #0 */
-
- midgard_vector_alu_src alu_src = blank_alu_src;
- alu_src.mod = midgard_int_zero_extend;
- alu_src.half = true;
-
- midgard_instruction u2f = {
- .type = TAG_ALU_4,
- .ssa_args = {
- .src0 = reg,
- .src1 = SSA_UNUSED_0,
- .dest = reg,
- .inline_constant = true
- },
- .alu = {
- .op = midgard_alu_op_u2f_rtz,
- .reg_mode = midgard_reg_mode_16,
- .dest_override = midgard_dest_override_none,
- .mask = 0xF,
- .src1 = vector_alu_srco_unsigned(alu_src),
- .src2 = vector_alu_srco_unsigned(blank_alu_src),
- }
- };
-
- emit_mir_instruction(ctx, u2f);
-
- /* vmul.fmul.sat r1, hr2, #0.00392151 */
-
- alu_src.mod = 0;
-
- midgard_instruction fmul = {
- .type = TAG_ALU_4,
- .inline_constant = _mesa_float_to_half(1.0 / 255.0),
- .ssa_args = {
- .src0 = reg,
- .dest = reg,
- .src1 = SSA_UNUSED_0,
- .inline_constant = true
- },
- .alu = {
- .op = midgard_alu_op_fmul,
- .reg_mode = midgard_reg_mode_32,
- .dest_override = midgard_dest_override_none,
- .outmod = midgard_outmod_sat,
- .mask = 0xFF,
- .src1 = vector_alu_srco_unsigned(alu_src),
- .src2 = vector_alu_srco_unsigned(blank_alu_src),
- }
- };
-
- emit_mir_instruction(ctx, fmul);
-}
-