From: Jason Ekstrand Date: Thu, 7 Sep 2017 01:37:34 +0000 (-0700) Subject: intel/fs: Don't stomp f0.1 in SIMD16 ballot X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=6c00240bc650805e0b66aa6e17dbe69bbe41e446;p=mesa.git intel/fs: Don't stomp f0.1 in SIMD16 ballot 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. Reviewed-by: Iago Toral Quiroga Cc: mesa-stable@lists.freedesktop.org --- diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp index f29d4e809ce..dcd9942f369 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);