org.lwjgl.vulkan

Class EXTShaderSubgroupBallot

java.lang.Object

org.lwjgl.vulkan.EXTShaderSubgroupBallot

public final class EXTShaderSubgroupBallot
extends java.lang.Object

This extension adds support for the following SPIR-V extension in Vulkan:

• SPV_KHR_shader_ballot

This extension provides the ability for a group of invocations, which execute in parallel, to do limited forms of cross-invocation communication via a group broadcast of a invocation value, or broadcast of a bitarray representing a predicate value from each invocation in the group.

This extension provides access to a number of additional built-in shader variables in Vulkan:

• SubgroupEqMaskKHR, which contains the subgroup mask of the current subgroup invocation,
• SubgroupGeMaskKHR, which contains the subgroup mask of the invocations greater than or equal to the current invocation,
• SubgroupGtMaskKHR, which contains the subgroup mask of the invocations greater than the current invocation,
• SubgroupLeMaskKHR, which contains the subgroup mask of the invocations less than or equal to the current invocation,
• SubgroupLtMaskKHR, which contains the subgroup mask of the invocations less than the current invocation,
• SubgroupLocalInvocationId, which contains the index of an invocation within a subgroup, and
• SubgroupSize, which contains the maximum number of invocations in a subgroup.

Additionally, this extension provides access to the new SPIR-V instructions:

• OpSubgroupBallotKHR,
• OpSubgroupFirstInvocationKHR, and
• OpSubgroupReadInvocationKHR,

When using GLSL source-based shader languages, the following variables and shader functions from GL_ARB_shader_ballot can map to these SPIR-V built-in decorations and instructions:

• in uint64_t gl_SubGroupEqMaskARB; → SubgroupEqMaskKHR,
• in uint64_t gl_SubGroupGeMaskARB; → SubgroupGeMaskKHR,
• in uint64_t gl_SubGroupGtMaskARB; → SubgroupGtMaskKHR,
• in uint64_t gl_SubGroupLeMaskARB; → SubgroupLeMaskKHR,
• in uint64_t gl_SubGroupLtMaskARB; → SubgroupLtMaskKHR,
• in uint gl_SubGroupInvocationARB; → SubgroupLocalInvocationId,
• uniform uint gl_SubGroupSizeARB; → SubgroupSize,
• ballotARB() → OpSubgroupBallotKHR,
• readFirstInvocationARB() → OpSubgroupFirstInvocationKHR, and
• readInvocationARB() → OpSubgroupReadInvocationKHR.

Name String

VK_EXT_shader_subgroup_ballot

Extension Type

Device extension

Registered Extension Number

65

Revision

1

Extension and Version Dependencies

• Requires Vulkan 1.0

Contact

• Daniel Koch dgkoch

Last Modified Date

2016-11-28

IP Status

No known IP claims.

Interactions and External Dependencies

• This extension requires the SPV_KHR_shader_ballot SPIR-V extension.
• This extension requires the GL_ARB_shader_ballot extension for GLSL source languages.

Contributors

• Jeff Bolz, NVIDIA
• Neil Henning, Codeplay
• Daniel Koch, NVIDIA Corporation

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	VK_EXT_SHADER_SUBGROUP_BALLOT_EXTENSION_NAME The extension name.
static int	VK_EXT_SHADER_SUBGROUP_BALLOT_SPEC_VERSION The extension specification version.

Method Summary

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

VK_EXT_SHADER_SUBGROUP_BALLOT_SPEC_VERSION

public static final int VK_EXT_SHADER_SUBGROUP_BALLOT_SPEC_VERSION

The extension specification version.

See Also:

Constant Field Values

VK_EXT_SHADER_SUBGROUP_BALLOT_EXTENSION_NAME

public static final java.lang.String VK_EXT_SHADER_SUBGROUP_BALLOT_EXTENSION_NAME

The extension name.

See Also:

Constant Field Values