In fragment shaders f0.1 is used for discards so doing ballot after a discard can potentially cause the discard to not happen. However, we don't support SIMD32 fragment shaders yet so this isn't a problem.
Cc: mesa-sta...@lists.freedesktop.org --- src/intel/compiler/brw_fs_nir.cpp | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp index f29d4e8..dcd9942 100644 --- a/src/intel/compiler/brw_fs_nir.cpp +++ b/src/intel/compiler/brw_fs_nir.cpp @@ -4264,8 +4264,15 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr case nir_intrinsic_ballot: { const fs_reg value = retype(get_nir_src(instr->src[0]), BRW_REGISTER_TYPE_UD); - const struct brw_reg flag = retype(brw_flag_reg(0, 0), - BRW_REGISTER_TYPE_UD); + struct brw_reg flag = brw_flag_reg(0, 0); + /* FIXME: For SIMD32 programs, this causes us to stomp on f0.1 as well + * as f0.0. This is a problem for fragment programs as we currently use + * f0.1 for discards. Fortunately, we don't support SIMD32 fragment + * programs yet so this isn't a problem. When we do, something will + * have to change. + */ + if (dispatch_width == 32) + flag.type = BRW_REGISTER_TYPE_UD; bld.exec_all().MOV(flag, brw_imm_ud(0u)); bld.CMP(bld.null_reg_ud(), value, brw_imm_ud(0u), BRW_CONDITIONAL_NZ); -- 2.5.0.400.gff86faf _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev