ARB_gpu_shader5 requires UBO array indexing expressions to be dynamically uniform, this however doesn't have any implications on the control flow that leads to the evaluation of that expression being uniform. Use emit_uniformize() to obtain an arbitrary live value from the binding table index calculation instead of assuming that the first channel is always live.
Fixes the following Piglit tests: arb_gpu_shader5/execution/ubo_array_indexing/fs-nonuniform-control-flow.shader_test arb_gpu_shader5/execution/ubo_array_indexing/vs-nonuniform-control-flow.shader_test part of the series: http://lists.freedesktop.org/archives/piglit/2015-February/014616.html --- src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 8 ++++---- src/mesa/drivers/dri/i965/brw_fs_visitor.cpp | 8 ++++---- src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp | 5 +++-- 3 files changed, 11 insertions(+), 10 deletions(-) diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp index 90eecae..ad77752 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp @@ -1263,13 +1263,13 @@ fs_visitor::nir_emit_intrinsic(nir_intrinsic_instr *instr) const_index->u[0]); } else { /* The block index is not a constant. Evaluate the index expression - * per-channel and add the base UBO index; the generator will select - * a value from any live channel. + * per-channel and add the base UBO index; we have to select a value + * from any live channel. */ surf_index = vgrf(glsl_type::uint_type); emit(ADD(surf_index, get_nir_src(instr->src[0]), - fs_reg(stage_prog_data->binding_table.ubo_start))) - ->force_writemask_all = true; + fs_reg(stage_prog_data->binding_table.ubo_start))); + emit_uniformize(surf_index, surf_index); /* Assume this may touch any UBO. It would be nice to provide * a tighter bound, but the array information is already lowered away. diff --git a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp index 6f1ff20..dee6a6d 100644 --- a/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs_visitor.cpp @@ -1127,13 +1127,13 @@ fs_visitor::visit(ir_expression *ir) const_uniform_block->value.u[0]); } else { /* The block index is not a constant. Evaluate the index expression - * per-channel and add the base UBO index; the generator will select - * a value from any live channel. + * per-channel and add the base UBO index; we have to select a value + * from any live channel. */ surf_index = vgrf(glsl_type::uint_type); emit(ADD(surf_index, op[0], - fs_reg(stage_prog_data->binding_table.ubo_start))) - ->force_writemask_all = true; + fs_reg(stage_prog_data->binding_table.ubo_start))); + emit_uniformize(surf_index, surf_index); /* Assume this may touch any UBO. It would be nice to provide * a tighter bound, but the array information is already lowered away. diff --git a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp index 4515fc7..d5848d2 100644 --- a/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp +++ b/src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp @@ -1750,12 +1750,13 @@ vec4_visitor::visit(ir_expression *ir) const_uniform_block->value.u[0]); } else { /* The block index is not a constant. Evaluate the index expression - * per-channel and add the base UBO index; the generator will select - * a value from any live channel. + * per-channel and add the base UBO index; we have to select a value + * from any live channel. */ surf_index = src_reg(this, glsl_type::uint_type); emit(ADD(dst_reg(surf_index), op[0], src_reg(prog_data->base.binding_table.ubo_start))); + emit_uniformize(dst_reg(surf_index), surf_index); /* Assume this may touch any UBO. It would be nice to provide * a tighter bound, but the array information is already lowered away. -- 2.1.3 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
