[Mesa-dev] [PATCH 09/13] anv: Implement vkCmdDrawIndirectByteCountEXT

Lionel Landwerlin lionel.g.landwerlin at intel.com
Mon Oct 15 12:06:30 UTC 2018


On 13/10/2018 14:09, Jason Ekstrand wrote:
> Annoyingly, this requires that we implement integer division on the
> command streamer.  Fortunately, we're only ever dividing by constants so
> we can use the mulh+add+shift trick and it's not as bad as it sounds.
> ---
>   src/intel/vulkan/anv_device.c      |   2 +-
>   src/intel/vulkan/genX_cmd_buffer.c | 150 +++++++++++++++++++++++++++++
>   2 files changed, 151 insertions(+), 1 deletion(-)
>
> diff --git a/src/intel/vulkan/anv_device.c b/src/intel/vulkan/anv_device.c
> index 6395656dfd0..acca97b53d1 100644
> --- a/src/intel/vulkan/anv_device.c
> +++ b/src/intel/vulkan/anv_device.c
> @@ -1226,7 +1226,7 @@ void anv_GetPhysicalDeviceProperties2(
>            props->transformFeedbackQueries = VK_FALSE;
>            props->transformFeedbackStreamsLinesTriangles = VK_FALSE;
>            props->transformFeedbackRasterizationStreamSelect = VK_TRUE;
> -         props->transformFeedbackDraw = VK_FALSE;
> +         props->transformFeedbackDraw = VK_TRUE;
>            break;
>         }
>   
> diff --git a/src/intel/vulkan/genX_cmd_buffer.c b/src/intel/vulkan/genX_cmd_buffer.c
> index 90469abbf21..1fbcfaf4264 100644
> --- a/src/intel/vulkan/genX_cmd_buffer.c
> +++ b/src/intel/vulkan/genX_cmd_buffer.c
> @@ -27,6 +27,7 @@
>   #include "anv_private.h"
>   #include "vk_format_info.h"
>   #include "vk_util.h"
> +#include "util/fast_idiv_by_const.h"
>   
>   #include "common/gen_l3_config.h"
>   #include "genxml/gen_macros.h"
> @@ -2880,7 +2881,156 @@ emit_mul_gpr0(struct anv_batch *batch, uint32_t N)
>      build_alu_multiply_gpr0(dw + 1, &num_dwords, N);
>   }
>   
> +static void
> +emit_alu_add(struct anv_batch *batch, unsigned dst_reg,
> +             unsigned reg_a, unsigned reg_b)
> +{
> +   uint32_t *dw = anv_batch_emitn(batch, 1 + 4, GENX(MI_MATH));
> +   dw[1] = mi_alu(MI_ALU_LOAD, MI_ALU_SRCA, reg_a);
> +   dw[2] = mi_alu(MI_ALU_LOAD, MI_ALU_SRCB, reg_b);
> +   dw[3] = mi_alu(MI_ALU_ADD, 0, 0);
> +   dw[4] = mi_alu(MI_ALU_STORE, dst_reg, MI_ALU_ACCU);
> +}
> +
> +static void
> +emit_add32_gpr0(struct anv_batch *batch, uint32_t N)
> +{
> +   emit_lri(batch, CS_GPR(1), N);
> +   emit_alu_add(batch, MI_ALU_REG0, MI_ALU_REG0, MI_ALU_REG1);
> +}
> +
> +static void
> +emit_alu_shl(struct anv_batch *batch, unsigned dst_reg,
> +             unsigned src_reg, unsigned shift)
> +{
> +   assert(shift > 0);
> +
> +   uint32_t *dw = anv_batch_emitn(batch, 1 + 4 * shift, GENX(MI_MATH));
> +   for (unsigned i = 0; i < shift; i++) {
> +      unsigned add_src = (i == 0) ? src_reg : dst_reg;
> +      dw[1 + (i * 4) + 0] = mi_alu(MI_ALU_LOAD, MI_ALU_SRCA, add_src);
> +      dw[1 + (i * 4) + 1] = mi_alu(MI_ALU_LOAD, MI_ALU_SRCB, add_src);
> +      dw[1 + (i * 4) + 2] = mi_alu(MI_ALU_ADD, 0, 0);
> +      dw[1 + (i * 4) + 3] = mi_alu(MI_ALU_STORE, dst_reg, MI_ALU_ACCU);
> +   }
> +}
> +
> +static void
> +emit_div32_gpr0(struct anv_batch *batch, uint32_t D)
> +{
> +   /* Zero out the top of GPR0 */
> +   emit_lri(batch, CS_GPR(0) + 4, 0);
> +
> +   if (D == 0) {
> +      /* This invalid, but we should do something so we set GPR0 to 0. */
> +      emit_lri(batch, CS_GPR(0), 0);
> +   } else if (util_is_power_of_two_or_zero(D)) {
> +      unsigned log2_D = util_logbase2(D);
> +      assert(log2_D < 32);
> +      /* We right-shift by log2(D) by left-shifting by 32 - log2(D) and taking
> +       * the top 32 bits of the result.
> +       */
> +      emit_alu_shl(batch, MI_ALU_REG0, MI_ALU_REG0, 32 - log2_D);
> +      emit_lrr(batch, CS_GPR(0) + 0, CS_GPR(0) + 4);
> +      emit_lri(batch, CS_GPR(0) + 4, 0);
> +   } else {
> +      struct util_fast_udiv_info m = util_compute_fast_udiv_info(D, 32, 32);
> +      assert(m.multiplier <= UINT32_MAX);
> +
> +      if (m.pre_shift) {
> +         /* We right-shift by L by left-shifting by 32 - l and taking the top
> +          * 32 bits of the result.
> +          */
> +         if (m.pre_shift < 32)
> +            emit_alu_shl(batch, MI_ALU_REG0, MI_ALU_REG0, 32 - m.pre_shift);
> +         emit_lrr(batch, CS_GPR(0) + 0, CS_GPR(0) + 4);
> +         emit_lri(batch, CS_GPR(0) + 4, 0);
> +      }
> +
> +      /* Do the 32x32 multiply  into gpr0 */
> +      emit_mul_gpr0(batch, m.multiplier);
> +
> +      if (m.increment) {
> +         /* If we need to increment, save off a copy of GPR0 */
> +         emit_lri(batch, CS_GPR(1) + 0, m.multiplier);
> +         emit_lri(batch, CS_GPR(1) + 4, 0);
> +         emit_alu_add(batch, MI_ALU_REG0, MI_ALU_REG0, MI_ALU_REG1);
> +      }
> +
> +      /* Shift by 32 */
> +      emit_lrr(batch, CS_GPR(0) + 0, CS_GPR(0) + 4);
> +      emit_lri(batch, CS_GPR(0) + 4, 0);
> +
> +      if (m.post_shift) {
> +         /* We right-shift by L by left-shifting by 32 - l and taking the top
> +          * 32 bits of the result.
> +          */
> +         if (m.post_shift < 32)
> +            emit_alu_shl(batch, MI_ALU_REG0, MI_ALU_REG0, 32 - m.post_shift);
> +         emit_lrr(batch, CS_GPR(0) + 0, CS_GPR(0) + 4);
> +         emit_lri(batch, CS_GPR(0) + 4, 0);
> +      }
> +   }
> +}
> +
> +#endif /* GEN_IS_HASWELL || GEN_GEN >= 8 */
> +
> +void genX(CmdDrawIndirectByteCountEXT)(
> +    VkCommandBuffer                             commandBuffer,
> +    uint32_t                                    instanceCount,
> +    uint32_t                                    firstInstance,
> +    VkBuffer                                    counterBuffer,
> +    VkDeviceSize                                counterBufferOffset,
> +    uint32_t                                    counterOffset,
> +    uint32_t                                    vertexStride)
> +{
> +#if GEN_IS_HASWELL || GEN_GEN >= 8
> +   ANV_FROM_HANDLE(anv_cmd_buffer, cmd_buffer, commandBuffer);
> +   ANV_FROM_HANDLE(anv_buffer, counter_buffer, counterBuffer);
> +   struct anv_pipeline *pipeline = cmd_buffer->state.gfx.base.pipeline;
> +   const struct brw_vs_prog_data *vs_prog_data = get_vs_prog_data(pipeline);
> +
> +   /* firstVertex is always zero for this draw function */
> +   const uint32_t firstVertex = 0;
> +
> +   if (GEN_GEN == 7 && !GEN_IS_HASWELL)
> +      return;


I think this isn't needed as you've got the right #if above.


> +
> +   if (anv_batch_has_error(&cmd_buffer->batch))
> +      return;
> +
> +   genX(cmd_buffer_flush_state)(cmd_buffer);
> +
> +   if (vs_prog_data->uses_firstvertex ||
> +       vs_prog_data->uses_baseinstance)
> +      emit_base_vertex_instance(cmd_buffer, firstVertex, firstInstance);
> +   if (vs_prog_data->uses_drawid)
> +      emit_draw_index(cmd_buffer, 0);
> +
> +   /* Our implementation of VK_KHR_multiview uses instancing to draw the
> +    * different views.  We need to multiply instanceCount by the view count.
> +    */
> +   instanceCount *= anv_subpass_view_count(cmd_buffer->state.subpass);
> +
> +   emit_lrm(&cmd_buffer->batch, CS_GPR(0),
> +            anv_address_add(counter_buffer->address, counterBufferOffset));
> +   if (counterOffset)
> +      emit_add32_gpr0(&cmd_buffer->batch, -counterOffset);
> +   emit_div32_gpr0(&cmd_buffer->batch, vertexStride);
> +   emit_lrr(&cmd_buffer->batch, GEN7_3DPRIM_VERTEX_COUNT, CS_GPR(0));
> +
> +   emit_lri(&cmd_buffer->batch, GEN7_3DPRIM_START_VERTEX, firstVertex);
> +   emit_lri(&cmd_buffer->batch, GEN7_3DPRIM_INSTANCE_COUNT, instanceCount);
> +   emit_lri(&cmd_buffer->batch, GEN7_3DPRIM_START_INSTANCE, firstInstance);
> +   emit_lri(&cmd_buffer->batch, GEN7_3DPRIM_BASE_VERTEX, 0);
> +
> +   anv_batch_emit(&cmd_buffer->batch, GENX(3DPRIMITIVE), prim) {
> +      prim.IndirectParameterEnable  = true;
> +      prim.VertexAccessType         = SEQUENTIAL;
> +      prim.PrimitiveTopologyType    = pipeline->topology;
> +   }
>   #endif /* GEN_IS_HASWELL || GEN_GEN >= 8 */
> +}
>   
>   static void
>   load_indirect_parameters(struct anv_cmd_buffer *cmd_buffer,




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