Author :
Richard Townsend
Date :
2021-01-05 20:23:11
Hash :74e6ea45 Message :Neon: Fix Huffman enc. error w/Visual Studio+Clang
The GNU builtin function __builtin_clzl() accepts an unsigned long
argument, which is 8 bytes wide on LP64 systems (most Un*x systems,
including Mac) but 4 bytes wide on LLP64 systems (Windows.) This caused
the Neon intrinsics implementation of Huffman encoding to produce
mathematically incorrect results when compiled using Visual Studio with
Clang.
This commit changes all invocations of __builtin_clzl() in the Neon SIMD
extensions to __builtin_clzll(), which accepts an unsigned long long
argument that is guaranteed to be 8 bytes wide on all systems.
Fixes #480
Closes #490
Richard Townsend