C Specification

Several of the synchronization commands include pipeline stage parameters, restricting the synchronization scopes for that command to just those stages. This allows fine grained control over the exact execution dependencies and accesses performed by action commands. Implementations should use these pipeline stages to avoid unnecessary stalls or cache flushing.

Bits which can be set, specifying pipeline stages, are:

typedef enum VkPipelineStageFlagBits {
VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT = 0x00000001,
VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT = 0x00000002,
VK_PIPELINE_STAGE_VERTEX_INPUT_BIT = 0x00000004,
VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT = 0x00000100,
VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT = 0x00000200,
VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT = 0x00000400,
VK_PIPELINE_STAGE_TRANSFER_BIT = 0x00001000,
VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT = 0x00002000,
VK_PIPELINE_STAGE_HOST_BIT = 0x00004000,
VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT = 0x00008000,
VK_PIPELINE_STAGE_ALL_COMMANDS_BIT = 0x00010000,
VK_PIPELINE_STAGE_TRANSFORM_FEEDBACK_BIT_EXT = 0x01000000,
VK_PIPELINE_STAGE_CONDITIONAL_RENDERING_BIT_EXT = 0x00040000,
VK_PIPELINE_STAGE_COMMAND_PROCESS_BIT_NVX = 0x00020000,
VK_PIPELINE_STAGE_ACCELERATION_STRUCTURE_BUILD_BIT_NV = 0x02000000,
VK_PIPELINE_STAGE_FRAGMENT_DENSITY_PROCESS_BIT_EXT = 0x00800000,
VK_PIPELINE_STAGE_FLAG_BITS_MAX_ENUM = 0x7FFFFFFF
} VkPipelineStageFlagBits;

Description

• VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT specifies the stage of the pipeline where any commands are initially received by the queue.

• VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT specifies the stage of the pipeline where Draw/DispatchIndirect data structures are consumed. This stage also includes reading commands written by vkCmdProcessCommandsNVX.

• VK_PIPELINE_STAGE_TASK_SHADER_BIT_NV specifies the task shader stage.

• VK_PIPELINE_STAGE_MESH_SHADER_BIT_NV specifies the mesh shader stage.

• VK_PIPELINE_STAGE_VERTEX_INPUT_BIT specifies the stage of the pipeline where vertex and index buffers are consumed.

• VK_PIPELINE_STAGE_VERTEX_SHADER_BIT specifies the vertex shader stage.

• VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT specifies the tessellation control shader stage.

• VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT specifies the tessellation evaluation shader stage.

• VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT specifies the geometry shader stage.

• VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT specifies the fragment shader stage.

• VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT specifies the stage of the pipeline where early fragment tests (depth and stencil tests before fragment shading) are performed. This stage also includes subpass load operations for framebuffer attachments with a depth/stencil format.

• VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT specifies the stage of the pipeline where late fragment tests (depth and stencil tests after fragment shading) are performed. This stage also includes subpass store operations for framebuffer attachments with a depth/stencil format.

• VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT specifies the stage of the pipeline after blending where the final color values are output from the pipeline. This stage also includes subpass load and store operations and multisample resolve operations for framebuffer attachments with a color or depth/stencil format.

• VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT specifies the execution of a compute shader.

• VK_PIPELINE_STAGE_TRANSFER_BIT specifies the execution of copy commands. This includes the operations resulting from all copy commands, clear commands (with the exception of vkCmdClearAttachments), and vkCmdCopyQueryPoolResults.

• VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT specifies the final stage in the pipeline where operations generated by all commands complete execution.

• VK_PIPELINE_STAGE_HOST_BIT specifies a pseudo-stage indicating execution on the host of reads/writes of device memory. This stage is not invoked by any commands recorded in a command buffer.

• VK_PIPELINE_STAGE_RAY_TRACING_SHADER_BIT_NV specifies the execution of the ray tracing shader stages.

• VK_PIPELINE_STAGE_ACCELERATION_STRUCTURE_BUILD_BIT_NV specifies the execution of vkCmdBuildAccelerationStructureNV, vkCmdCopyAccelerationStructureNV, and vkCmdWriteAccelerationStructuresPropertiesNV.

• VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT specifies the execution of all graphics pipeline stages, and is equivalent to the logical OR of:

• VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT

• VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT

• VK_PIPELINE_STAGE_TASK_SHADER_BIT_NV

• VK_PIPELINE_STAGE_MESH_SHADER_BIT_NV

• VK_PIPELINE_STAGE_VERTEX_INPUT_BIT

• VK_PIPELINE_STAGE_VERTEX_SHADER_BIT

• VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT

• VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT

• VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT

• VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT

• VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT

• VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT

• VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT

• VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT

• VK_PIPELINE_STAGE_CONDITIONAL_RENDERING_BIT_EXT

• VK_PIPELINE_STAGE_TRANSFORM_FEEDBACK_BIT_EXT

• VK_PIPELINE_STAGE_SHADING_RATE_IMAGE_BIT_NV

• VK_PIPELINE_STAGE_FRAGMENT_DENSITY_PROCESS_BIT_EXT

• VK_PIPELINE_STAGE_ALL_COMMANDS_BIT is equivalent to the logical OR of every other pipeline stage flag that is supported on the queue it is used with.

• VK_PIPELINE_STAGE_CONDITIONAL_RENDERING_BIT_EXT specifies the stage of the pipeline where the predicate of conditional rendering is consumed.

• VK_PIPELINE_STAGE_TRANSFORM_FEEDBACK_BIT_EXT specifies the stage of the pipeline where vertex attribute output values are written to the transform feedback buffers.

• VK_PIPELINE_STAGE_COMMAND_PROCESS_BIT_NVX specifies the stage of the pipeline where device-side generation of commands via vkCmdProcessCommandsNVX is handled.

• VK_PIPELINE_STAGE_SHADING_RATE_IMAGE_BIT_NV specifies the stage of the pipeline where the shading rate image is read to determine the shading rate for portions of a rasterized primitive.

• VK_PIPELINE_STAGE_FRAGMENT_DENSITY_PROCESS_BIT_EXT specifies the stage of the pipeline where the fragment density map is read to generate the fragment areas.

 Note An execution dependency with only VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT in the destination stage mask will only prevent that stage from executing in subsequently submitted commands. As this stage does not perform any actual execution, this is not observable - in effect, it does not delay processing of subsequent commands. Similarly an execution dependency with only VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT in the source stage mask will effectively not wait for any prior commands to complete. When defining a memory dependency, using only VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT or VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT would never make any accesses available and/or visible because these stages do not access memory. VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT and VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT are useful for accomplishing layout transitions and queue ownership operations when the required execution dependency is satisfied by other means - for example, semaphore operations between queues.