tools/libdeflate/patches/0001-lib-x86-increase-AVX-VNNI-gcc-prerequisite-to-12.1.patch

   1 From e522b1d09d3536ddc15459b4259150f4a53ee65a Mon Sep 17 00:00:00 2001
   2 From: Eric Biggers <ebiggers@google.com>
   3 Date: Thu, 4 Apr 2024 20:16:33 -0400
   4 Subject: [PATCH] lib/x86: increase AVX-VNNI gcc prerequisite to 12.1
   5
   6 Although gcc 11.1 supports AVX-VNNI, a popular distro pairs it with a
   7 binutils version that does not.  Require gcc 12 instead.
   8
   9 Resolves https://github.com/ebiggers/libdeflate/issues/365
  10 ---
  11  lib/x86/adler32_impl.h | 9 ++++++++-
  12  1 file changed, 8 insertions(+), 1 deletion(-)
  13
  14 --- a/lib/x86/adler32_impl.h
  15 +++ b/lib/x86/adler32_impl.h
  16 @@ -52,8 +52,15 @@
  17  /*
  18   * AVX-VNNI implementation.  This is used on CPUs that have AVX2 and AVX-VNNI
  19   * but don't have AVX-512, for example Intel Alder Lake.
  20 + *
  21 + * Unusually for a new CPU feature, gcc added support for the AVX-VNNI
  22 + * intrinsics (in gcc 11.1) slightly before binutils added support for
  23 + * assembling AVX-VNNI instructions (in binutils 2.36).  Distros can reasonably
  24 + * have gcc 11 with binutils 2.35.  Because of this issue, we check for gcc 12
  25 + * instead of gcc 11.  (libdeflate supports direct compilation without a
  26 + * configure step, so checking the binutils version is not always an option.)
  27   */
  28 -#if GCC_PREREQ(11, 1) || CLANG_PREREQ(12, 0, 13000000) || MSVC_PREREQ(1930)
  29 +#if GCC_PREREQ(12, 1) || CLANG_PREREQ(12, 0, 13000000) || MSVC_PREREQ(1930)
  30  #  define adler32_x86_avx2_vnni        adler32_x86_avx2_vnni
  31  #  define SUFFIX                          _avx2_vnni
  32  #  define ATTRIBUTES           _target_attribute("avx2,avxvnni")