Docs: Add --disable-arm64-crc32 description to INSTALL.

This commit is contained in:
Jia Tan 2024-01-22 22:08:45 +08:00
parent 1940f0ec28
commit 30a25f3742
1 changed files with 11 additions and 1 deletions

12
INSTALL
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@ -372,7 +372,7 @@ XZ Utils Installation
code. code.
--disable-clmul-crc --disable-clmul-crc
Disable the use carryless multiplication for CRC Disable the use of carryless multiplication for CRC
calculation even if compiler support for it is detected. calculation even if compiler support for it is detected.
The code uses runtime detection of SSSE3, SSE4.1, and The code uses runtime detection of SSSE3, SSE4.1, and
CLMUL instructions on x86. On 32-bit x86 this currently CLMUL instructions on x86. On 32-bit x86 this currently
@ -383,6 +383,16 @@ XZ Utils Installation
required extensions (-msse4.1 -mpclmul) then runtime required extensions (-msse4.1 -mpclmul) then runtime
detection isn't used and the generic code is omitted. detection isn't used and the generic code is omitted.
--disable-arm64-crc32
Disable the use of the ARM64 CRC32 instruction extension
even if compiler support for it is detected. The code will
detect support for the instruction at runtime.
If using compiler options that unconditionally allow the
required extensions (-march=armv8-a+crc or -march=armv8.1-a
and later) then runtime detection isn't used and the
generic code is omitted.
--enable-unaligned-access --enable-unaligned-access
Allow liblzma to use unaligned memory access for 16-bit, Allow liblzma to use unaligned memory access for 16-bit,
32-bit, and 64-bit loads and stores. This should be 32-bit, and 64-bit loads and stores. This should be