README
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compress
Overview
Package compress implements the BLAKE-224 and BLAKE-256 block compression
function. It provides a pure Go implementation as well as specialized
implementations that take advantage of vector extensions (SSE2, SSE4.1, and AVX)
on the amd64 architecture when they are supported.
The package detects hardware support and arranges for the exported Blocks
function to automatically use the fastest available supported hardware
extensions that are not disabled.
Tests and Benchmarks
The package also provides full tests for all implementations as well as benchmarks. However, do note that since the specialized implementations require hardware support, the tests and benchmarks for them will be skipped when running on hardware that does not support the required extensions.
It is possible to test all implementations without hardware support by using software such as the Intel Software Development Emulator.
Some relevant flags for testing purposes with the Intel SDE are:
- SSE2:
-p4p Set chip-check and CPUID for Intel(R) Pentium4 Prescott CPU - SSE41:
-pnr Set chip-check and CPUID for Intel(R) Penryn CPU - AVX:
-snb Set chip-check and CPUID for Intel(R) Sandy Bridge CPU
Disabling Assembler Optimizations
The purego build tag may be used to disable all assembly code.
Additionally, when built normally without the purego build tag, the assembly
optimizations for each of the supported vector extensions can individually be
disabled at runtime by setting the following environment variables to 1.
BLAKE256_DISABLE_AVX=1: Disable Advanced Vector Extensions (AVX) optimizationsBLAKE256_DISABLE_SSE41=1: Disable Streaming SIMD Extensions 4.1 (SSE4.1) optimizationsBLAKE256_DISABLE_SSE2=1: Disable Streaming SIMD Extensions 2 (SSE2) optimizations
Installation and Updating
This package is internal and therefore is neither directly installed nor needs to be manually updated.
License
Package compress is licensed under the copyfree ISC License.
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func Blocks ¶
Blocks performs BLAKE-224 and BLAKE-256 block compression using processor specific vector extensions when available. It will compress as many full blocks as are available in the provided message.
The parameters are:
state: the block compression state with the chain value and salt msg: the padded message to compress (must be at least 64 bytes) counter: the total number of message bits hashed so far
It will panic if the provided message block does not have at least 64 bytes.
The chain value in the passed state is updated in place.
Source Files