SHA-512: Add AVX and AVX2 implementations for x86-64

* cipher/Makefile.am: Add 'sha512-avx-amd64.S' and
'sha512-avx2-bmi2-amd64.S'.
* cipher/sha512-avx-amd64.S: New.
* cipher/sha512-avx2-bmi2-amd64.S: New.
* cipher/sha512.c (USE_AVX, USE_AVX2): New.
(SHA512_CONTEXT) [USE_AVX]: Add 'use_avx'.
(SHA512_CONTEXT) [USE_AVX2]: Add 'use_avx2'.
(sha512_init, sha384_init) [USE_AVX]: Initialize 'use_avx'.
(sha512_init, sha384_init) [USE_AVX2]: Initialize 'use_avx2'.
[USE_AVX] (_gcry_sha512_transform_amd64_avx): New.
[USE_AVX2] (_gcry_sha512_transform_amd64_avx2): New.
(transform) [USE_AVX2]: Add call for AVX2 implementation.
(transform) [USE_AVX]: Add call for AVX implementation.
* configure.ac (HAVE_GCC_INLINE_ASM_BMI2): New check.
(sha512): Add 'sha512-avx-amd64.lo' and 'sha512-avx2-bmi2-amd64.lo'.
* doc/gcrypt.texi: Document 'intel-cpu' and 'intel-bmi2'.
* src/g10lib.h (HWF_INTEL_CPU, HWF_INTEL_BMI2): New.
* src/hwfeatures.c (hwflist): Add "intel-cpu" and "intel-bmi2".
* src/hwf-x86.c (detect_x86_gnuc): Check for HWF_INTEL_CPU and
HWF_INTEL_BMI2.
--

Patch adds fast AVX and AVX2 implementation of SHA-512 by Intel Corporation.
The assembly source is licensed under 3-clause BSD license, thus compatible
with LGPL2.1+. Original source can be accessed at:
 http://www.intel.com/p/en_US/embedded/hwsw/technology/packet-processing#docs

Implementation is described in white paper
 "Fast SHA512 Implementations on Intel® Architecture Processors"
 http://www.intel.com/content/www/us/en/intelligent-systems/intel-technology/fast-sha512-implementat$

Note: AVX implementation uses SHLD instruction to emulate RORQ, since it's
      faster on Intel Sandy-Bridge. However, on non-Intel CPUs SHLD is much
      slower than RORQ, so therefore AVX implementation is (for now) limited
      to Intel CPUs.
Note: AVX2 implementation also uses BMI2 instruction rorx, thus additional
      HWF flag.

Benchmarks:

cpu                 Old         SSSE3       AVX/AVX2   Old vs AVX/AVX2
                                                              vs SSSE3
Intel i5-4570       10.11 c/B    7.56 c/B   6.72 c/B   1.50x  1.12x
Intel i5-2450M      14.11 c/B   10.53 c/B   8.88 c/B   1.58x  1.18x

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/hwf-x86.c b/src/hwf-x86.c
index ab6dacdc..4e825588 100644
--- a/src/hwf-x86.c
+++ b/src/hwf-x86.c
@@ -189,6 +189,7 @@ detect_x86_gnuc (void)
   else if (!strcmp (vendor_id, "GenuineIntel"))
     {
       /* This is an Intel CPU.  */
+      result |= HWF_INTEL_CPU;
     }
   else if (!strcmp (vendor_id, "AuthenticAMD"))
     {
@@ -231,10 +232,14 @@ detect_x86_gnuc (void)
    * Source: http://www.sandpile.org/x86/cpuid.htm  */
   if (max_cpuid_level >= 7 && (features & 0x00000001))
     {
-#ifdef ENABLE_AVX2_SUPPORT
       /* Get CPUID:7 contains further Intel feature flags. */
       get_cpuid(7, NULL, &features, NULL, NULL);
 
+      /* Test bit 8 for BMI2.  */
+      if (features & 0x00000100)
+          result |= HWF_INTEL_BMI2;
+
+#ifdef ENABLE_AVX2_SUPPORT
       /* Test bit 5 for AVX2.  */
       if (features & 0x00000020)
           result |= HWF_INTEL_AVX2;