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Mojo module

id

This module provides GPU thread and block indexing functionality.

It defines aliases and functions for accessing GPU grid, block, thread and cluster dimensions and indices. These are essential primitives for GPU programming that allow code to determine its position and dimensions within the GPU execution hierarchy.

Most functionality is architecture-agnostic, with some NVIDIA-specific features clearly marked. The module is designed to work seamlessly across different GPU architectures while providing optimal performance through hardware-specific optimizations where applicable.

Aliases

block_dim

alias block_dim = _BlockDim()

Contains the dimensions of the block as x, y, and z values (for example, block_dim.y)

block_id_in_cluster

alias block_id_in_cluster = _Cluster_BlockIdx()

Contains the block id of the threadblock within a cluster, as x, y, and z values.

block_idx

alias block_idx = _BlockIdx()

Contains the block index in the grid, as x, y, and z values.

cluster_dim

alias cluster_dim = _ClusterDim()

Contains the dimensions of the cluster, as x, y, and z values.

cluster_idx

alias cluster_idx = _ClusterIdx()

Contains the cluster index in the grid, as x, y, and z values.

global_idx

alias global_idx = _GridIdx()

Contains the global offset of the kernel launch, as x, y, and z values.

grid_dim

alias grid_dim = _GridDim()

Provides accessors for getting the x, y, and z dimensions of a grid.

thread_idx

alias thread_idx = _ThreadIdx()

Contains the thread index in the block, as x, y, and z values.

Functions

  • lane_id: Returns the lane ID of the current thread within its warp.
  • sm_id: Returns the Streaming Multiprocessor (SM) ID of the current thread.
  • warp_id: Returns the warp ID of the current thread within its block. The warp ID is a unique identifier for each warp within a block, ranging from 0 to BLOCK_SIZE/WARP_SIZE-1. This ID is commonly used for warp-level programming and synchronization within a block.

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