[glibc] x86: Remove __mmask intrinsics in strstr-avx512.c

[glibc] x86: Remove __mmask intrinsics in strstr-avx512.c

[Noah Goldstein]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=f2698954ff9c2f9626d4bcb5a30eb5729714e0b0

commit f2698954ff9c2f9626d4bcb5a30eb5729714e0b0
Author: Noah Goldstein <goldstein.w.n@gmail.com>
Date:   Tue Jul 12 11:48:04 2022 -0700

    x86: Remove __mmask intrinsics in strstr-avx512.c
    
    The intrinsics are not available before GCC7 and using standard
    operators generates code of equivalent or better quality.
    
    Removed:
        _cvtmask64_u64
        _kshiftri_mask64
        _kand_mask64
    
    Geometric Mean of 5 Runs of Full Benchmark Suite New / Old: 0.958

Diff:
---
 sysdeps/x86_64/multiarch/strstr-avx512.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/sysdeps/x86_64/multiarch/strstr-avx512.c b/sysdeps/x86_64/multiarch/strstr-avx512.c
index 2ab9e96db8..e44c1a05dc 100644
--- a/sysdeps/x86_64/multiarch/strstr-avx512.c
+++ b/sysdeps/x86_64/multiarch/strstr-avx512.c
@@ -26,6 +26,10 @@
 #define ZMM_SIZE_IN_BYTES 64
 #define PAGESIZE 4096
 
+#define cvtmask64_u64(...) (uint64_t) (__VA_ARGS__)
+#define kshiftri_mask64(x, y) ((x) >> (y))
+#define kand_mask64(x, y) ((x) & (y))
+
 /*
  Returns the index of the first edge within the needle, returns 0 if no edge
  is found. Example: 'ab' is the first edge in 'aaaaaaaaaabaarddg'
@@ -133,15 +137,15 @@ __strstr_avx512 (const char *haystack, const char *ned)
   __m512i hay0 = _mm512_maskz_loadu_epi8 (loadmask, haystack + hay_index);
   /* Search for NULL and compare only till null char */
   uint64_t nullmask
-      = _cvtmask64_u64 (_mm512_mask_testn_epi8_mask (loadmask, hay0, hay0));
+      = cvtmask64_u64 (_mm512_mask_testn_epi8_mask (loadmask, hay0, hay0));
   uint64_t cmpmask = nullmask ^ (nullmask - ONE_64BIT);
-  cmpmask = cmpmask & _cvtmask64_u64 (loadmask);
+  cmpmask = cmpmask & cvtmask64_u64 (loadmask);
   /* Search for the 2 charaters of needle */
   __mmask64 k0 = _mm512_cmpeq_epi8_mask (hay0, ned0);
   __mmask64 k1 = _mm512_cmpeq_epi8_mask (hay0, ned1);
-  k1 = _kshiftri_mask64 (k1, 1);
+  k1 = kshiftri_mask64 (k1, 1);
   /* k2 masks tell us if both chars from needle match */
-  uint64_t k2 = _cvtmask64_u64 (_kand_mask64 (k0, k1)) & cmpmask;
+  uint64_t k2 = cvtmask64_u64 (kand_mask64 (k0, k1)) & cmpmask;
   /* For every match, search for the entire needle for a full match */
   while (k2)
     {
@@ -178,13 +182,13 @@ __strstr_avx512 (const char *haystack, const char *ned)
       hay0 = _mm512_loadu_si512 (haystack + hay_index);
       hay1 = _mm512_load_si512 (haystack + hay_index
                                 + 1); // Always 64 byte aligned
-      nullmask = _cvtmask64_u64 (_mm512_testn_epi8_mask (hay1, hay1));
+      nullmask = cvtmask64_u64 (_mm512_testn_epi8_mask (hay1, hay1));
       /* Compare only till null char */
       cmpmask = nullmask ^ (nullmask - ONE_64BIT);
       k0 = _mm512_cmpeq_epi8_mask (hay0, ned0);
       k1 = _mm512_cmpeq_epi8_mask (hay1, ned1);
       /* k2 masks tell us if both chars from needle match */
-      k2 = _cvtmask64_u64 (_kand_mask64 (k0, k1)) & cmpmask;
+      k2 = cvtmask64_u64 (kand_mask64 (k0, k1)) & cmpmask;
       /* For every match, compare full strings for potential match */
       while (k2)
         {