CUB 1.2.3

Summary

CUB 1.2.3 is a minor release.

Bug Fixes

• Fixed access violation bug in cub::DeviceReduce::ReduceByKey for non-primitive value types.
• Fixed code-snippet bug in ArgIndexInputIteratorT documentation.

CUB 1.2.2

Summary

CUB 1.2.2 adds a new variant of cub::BlockReduce and MSVC project solections for examples.

New Features

• MSVC project solutions for device-wide and block-wide examples
• New algorithmic variant of cub::BlockReduce for improved performance when using commutative operators (e.g., numeric addition).

Bug Fixes

• Inclusion of Thrust headers in a certain order prevented CUB device-wide primitives from working properly.

CUB 1.2.0

Summary

CUB 1.2.0 adds cub::DeviceReduce::ReduceByKey and cub::DeviceReduce::RunLengthEncode and support for CUDA 6.0.

New Features

• cub::DeviceReduce::ReduceByKey.
• cub::DeviceReduce::RunLengthEncode.

Other Enhancements

• Improved cub::DeviceScan, cub::DeviceSelect, cub::DevicePartition performance.
• Documentation and testing:
  • Added performance-portability plots for many device-wide primitives.
  • Explain that iterator (in)compatibilities with CUDA 5.0 (and older) and Thrust 1.6 (and older).
• Revised the operation of temporary tile status bookkeeping for cub::DeviceScan (and similar) to be safe for current code run on future platforms (now uses proper fences).

Bug Fixes

• Fix cub::DeviceScan bug where Windows alignment disagreements between host and device regarding user-defined data types would corrupt tile status.
• Fix cub::BlockScan bug where certain exclusive scans on custom data types for the BLOCK_SCAN_WARP_SCANS variant would return incorrect results for the first thread in the block.
• Added workaround to make cub::TexRefInputIteratorT work with CUDA 6.0.

CUB 1.1.1

Summary

CUB 1.1.1 introduces texture and cache modifier iterators, descending sorting, cub::DeviceSelect, cub::DevicePartition, cub::Shuffle*, and cub::MaxSMOccupancy. Additionally, scan and sort performance for older GPUs has been improved and many bugs have been fixed.

Breaking Changes

• Refactored block-wide I/O (cub::BlockLoad and cub::BlockStore), removing cache-modifiers from their interfaces. cub::CacheModifiedInputIterator and cub::CacheModifiedOutputIterator should now be used with cub::BlockLoad and cub::BlockStore to effect that behavior.

New Features

• cub::TexObjInputIterator, cub::TexRefInputIterator, cub::CacheModifiedInputIterator, and cub::CacheModifiedOutputIterator types for loading & storing arbitrary types through the cache hierarchy. They are compatible with Thrust.
• Descending sorting for cub::DeviceRadixSort and cub::BlockRadixSort.
• Min, max, arg-min, and arg-max operators for cub::DeviceReduce.
• cub::DeviceSelect (select-unique, select-if, and select-flagged).
• cub::DevicePartition (partition-if, partition-flagged).
• Generic cub::ShuffleUp, cub::ShuffleDown, and cub::ShuffleIndex for warp-wide communication of arbitrary data types (SM3x and up).
• cub::MaxSmOccupancy for accurately determining SM occupancy for any given kernel function pointer.

Other Enhancements

• Improved cub::DeviceScan and cub::DeviceRadixSort performance for older GPUs (SM1x to SM3x).
• Renamed device-wide stream_synchronous param to debug_synchronous to avoid confusion about usage.
• Documentation improvements:
  • Added simple examples of device-wide methods.
  • Improved doxygen documentation and example snippets.
• Improved test coverege to include up to 21,000 kernel variants and 851,000 unit tests (per architecture, per platform).

Bug Fixes

• Fix misc `cub::DeviceScan, BlockScan, DeviceReduce, and BlockReduce bugs when operating on non-primitive types for older architectures SM1x.
• SHFL-based scans and reductions produced incorrect results for multi-word types (size > 4B) on Linux.
• For cub::WarpScan-based scans, not all threads in the first warp were entering the prefix callback functor.
• cub::DeviceRadixSort had a race condition with key-value pairs for pre-SM35 architectures.
• cub::DeviceRadixSor bitfield-extract behavior with long keys on 64-bit Linux was incorrect.
• cub::BlockDiscontinuity failed to compile for types other than int32_t/uint32_t.
• CUDA Dynamic Parallelism (CDP, e.g. device-callable) versions of device-wide methods now report the same temporary storage allocation size requirement as their host-callable counterparts.

CUB 1.0.2

Summary

CUB 1.0.2 is a minor release.

Bug Fixes

• Corrections to code snippet examples for cub::BlockLoad, cub::BlockStore, and cub::BlockDiscontinuity.
• Cleaned up unnecessary/missing header includes. You can now safely include a specific .cuh (instead of cub.cuh).
• Bug/compilation fixes for cub::BlockHistogram.

CUB 1.0.1

Summary

CUB 1.0.1 adds cub::DeviceRadixSort and cub::DeviceScan. Numerous other performance and correctness fixes and included.

Breaking Changes

• New collective interface idiom (specialize/construct/invoke).

New Features

• cub::DeviceRadixSort. Implements short-circuiting for homogenous digit passes.
• cub::DeviceScan. Implements single-pass "adaptive-lookback" strategy.

Other Enhancements

• Significantly improved documentation (with example code snippets).
• More extensive regression test suit for aggressively testing collective variants.
• Allow non-trially-constructed types (previously unions had prevented aliasing temporary storage of those types).
• Improved support for SM3x SHFL (collective ops now use SHFL for types larger than 32 bits).
• Better code generation for 64-bit addressing within cub::BlockLoad/cub::BlockStore.
• cub::DeviceHistogram now supports histograms of arbitrary bins.
• Updates to accommodate CUDA 5.5 dynamic parallelism.

Bug Fixes

• Workarounds for SM10 codegen issues in uncommonly-used cub::WarpScan/cub::WarpReduce specializations.

CUB 0.9.4

Summary

CUB 0.9.3 is a minor release.

Enhancements

• Various documentation updates and corrections.

Bug Fixes

• Fixed compilation errors for SM1x.
• Fixed compilation errors for some WarpScan entrypoints on SM3x and up.

CUB 0.9.3

Summary

CUB 0.9.3 adds histogram algorithms and work management utility descriptors.

New Features

• cub::DevicHistogram256.
• cub::BlockHistogram256.
• cub::BlockScan algorithm variant BLOCK_SCAN_RAKING_MEMOIZE, which trades more register consumption for less shared memory I/O.
• cub::GridQueue, cub::GridEvenShare, work management utility descriptors.

Other Enhancements

• Updates to cub::BlockRadixRank to use cub::BlockScan, which improves performance on SM3x by using SHFL.
• Allow types other than builtin types to be used in cub::WarpScan::*Sum methods if they only have operator+ overloaded. Previously they also required to support assignment from int(0).
• Update cub::BlockReduce's BLOCK_REDUCE_WARP_REDUCTIONS algorithm to work even when block size is not an even multiple of warp size.
• Refactoring of cub::DeviceAllocator interface and cub::CachingDeviceAllocator implementation.

CUB 0.9.2

Summary

CUB 0.9.2 adds cub::WarpReduce.

New Features

• cub::WarpReduce, which uses the SHFL instruction when applicable. cub::BlockReduce now uses this cub::WarpReduce instead of implementing its own.

Enhancements

• Documentation updates and corrections.

Bug Fixes

• Fixes for 64-bit Linux compilation warnings and errors.

CUB 0.9.1

Summary

CUB 0.9.1 is a minor release.

Bug Fixes

• Fix for ambiguity in cub::BlockScan::Reduce between generic reduction and summation. Summation entrypoints are now called ::Sum(), similar to the convention in cub::BlockScan.
• Small edits to documentation and download tracking.