v4-0001-Add-support-for-AVX512-implemented-POPCNT.patch

diff --git a/config/c-compiler.m4 b/config/c-compiler.m4
index 5db02b2ab7..a5a3246199 100644
--- a/config/c-compiler.m4
+++ b/config/c-compiler.m4
@@ -694,3 +694,36 @@ if test x"$Ac_cachevar" = x"yes"; then
 fi
 undefine([Ac_cachevar])dnl
 ])# PGAC_LOONGARCH_CRC32C_INTRINSICS
+
+# PGAC_AVX512_POPCNT_INTRINSICS
+# ---------------------------
+# Check if the compiler supports the x86_64 AVX512 POPCNT instructions using
+# intrinsics used in CPUID features AVX512F and AVX512VPOPCNTDQ.
+#
+# Optional compiler flags can be passed as argument (e.g. -mavx512vpopcntdq).
+# If the intrinsics are supported then pgac_avx512_popcnt_intrinsics and
+# CFLAGS_AVX512_POPCNT are set.
+AC_DEFUN([PGAC_AVX512_POPCNT_INTRINSICS],
+[define([Ac_cachevar], [AS_TR_SH([pgac_cv_avx512_popcnt_intrinsics_$1])])dnl
+AC_CACHE_CHECK([for _mm512_popcnt_epi64 with CFLAGS=$1], [Ac_cachevar],
+[pgac_save_CFLAGS=$CFLAGS
+CFLAGS="$pgac_save_CFLAGS $1"
+AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <immintrin.h>
+#include <stdint.h>],
+  [__m512i tmp __attribute__((aligned(64)));
+   __m512i input = _mm512_setzero_si512();
+   __m512i output = _mm512_popcnt_epi64(input);
+   uint64_t cnt = 999;
+   _mm512_store_si512(&tmp, output);
+   cnt = _mm512_reduce_add_epi64(tmp);
+   /* return computed value, to prevent the above being optimized away */
+   return cnt == 0;])],
+  [Ac_cachevar=yes],
+  [Ac_cachevar=no])
+CFLAGS="$pgac_save_CFLAGS"])
+if test x"$Ac_cachevar" = x"yes"; then
+  CFLAGS_AVX512_POPCNT="$1"
+  pgac_avx512_popcnt_intrinsics=yes
+fi
+undefine([Ac_cachevar])dnl
+])# PGAC_AVX512_POPCNT_INTRINSICS
diff --git a/configure b/configure
index 2a1ee251f2..7fe669cda2 100755
--- a/configure
+++ b/configure
@@ -647,6 +647,7 @@ MSGFMT_FLAGS
 MSGFMT
 PG_CRC32C_OBJS
 CFLAGS_CRC
+CFLAGS_AVX512_POPCNT
 LIBOBJS
 OPENSSL
 ZSTD
@@ -15209,7 +15210,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -15255,7 +15256,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -15279,7 +15280,7 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -15324,7 +15325,7 @@ else
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -15348,7 +15349,7 @@ rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
     We can't simply define LARGE_OFF_T to be 9223372036854775807,
     since some C++ compilers masquerading as C compilers
     incorrectly reject 9223372036854775807.  */
-#define LARGE_OFF_T (((off_t) 1 << 62) - 1 + ((off_t) 1 << 62))
+#define LARGE_OFF_T ((((off_t) 1 << 31) << 31) - 1 + (((off_t) 1 << 31) << 31))
   int off_t_is_large[(LARGE_OFF_T % 2147483629 == 721
 		       && LARGE_OFF_T % 2147483647 == 1)
 		      ? 1 : -1];
@@ -17702,6 +17703,41 @@ $as_echo "#define HAVE__GET_CPUID 1" >>confdefs.h
 
 fi
 
+# Check for x86 cpuid_count instruction
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __get_cpuid_count" >&5
+$as_echo_n "checking for __get_cpuid_count... " >&6; }
+if ${pgac_cv__get_cpuid_count+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <cpuid.h>
+int
+main ()
+{
+unsigned int exx[4] = {0, 0, 0, 0};
+  __get_cpuid_count(7, 0, &exx[0], &exx[1], &exx[2], &exx[3]);
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  pgac_cv__get_cpuid_count="yes"
+else
+  pgac_cv__get_cpuid_count="no"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv__get_cpuid_count" >&5
+$as_echo "$pgac_cv__get_cpuid_count" >&6; }
+if test x"$pgac_cv__get_cpuid_count" = x"yes"; then
+
+$as_echo "#define HAVE__GET_CPUID_COUNT 1" >>confdefs.h
+
+fi
+
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __cpuid" >&5
 $as_echo_n "checking for __cpuid... " >&6; }
 if ${pgac_cv__cpuid+:} false; then :
@@ -17736,6 +17772,164 @@ $as_echo "#define HAVE__CPUID 1" >>confdefs.h
 
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __cpuidex" >&5
+$as_echo_n "checking for __cpuidex... " >&6; }
+if ${pgac_cv__cpuidex+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <intrin.h>
+int
+main ()
+{
+unsigned int exx[4] = {0, 0, 0, 0};
+  __get_cpuidex(exx[0], 7, 0);
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  pgac_cv__cpuidex="yes"
+else
+  pgac_cv__cpuidex="no"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv__cpuidex" >&5
+$as_echo "$pgac_cv__cpuidex" >&6; }
+if test x"$pgac_cv__cpuidex" = x"yes"; then
+
+$as_echo "#define HAVE__CPUIDEX 1" >>confdefs.h
+
+fi
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __immintrin" >&5
+$as_echo_n "checking for __immintrin... " >&6; }
+if ${pgac_cv__immintrin+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <immintrin.h>
+int
+main ()
+{
+/* Don't exclude code so added return. */
+    return 1701;
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  pgac_cv__immintrin="yes"
+else
+  pgac_cv__immintrin="no"
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv__immintrin" >&5
+$as_echo "$pgac_cv__immintrin" >&6; }
+if test x"$pgac_cv__immintrin" = x"yes"; then
+
+$as_echo "#define HAVE__IMMINTRIN 1" >>confdefs.h
+
+fi
+
+# Check for Intel AVX512 intrinsics to do POPCNT calculations.
+#
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for _mm512_popcnt_epi64 with CFLAGS=" >&5
+$as_echo_n "checking for _mm512_popcnt_epi64 with CFLAGS=... " >&6; }
+if ${pgac_cv_avx512_popcnt_intrinsics_+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+CFLAGS="$pgac_save_CFLAGS "
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <immintrin.h>
+#include <stdint.h>
+int
+main ()
+{
+__m512i tmp __attribute__((aligned(64)));
+   __m512i input = _mm512_setzero_si512();
+   __m512i output = _mm512_popcnt_epi64(input);
+   uint64_t cnt = 999;
+   _mm512_store_si512(&tmp, output);
+   cnt = _mm512_reduce_add_epi64(tmp);
+   /* return computed value, to prevent the above being optimized away */
+   return cnt == 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  pgac_cv_avx512_popcnt_intrinsics_=yes
+else
+  pgac_cv_avx512_popcnt_intrinsics_=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+CFLAGS="$pgac_save_CFLAGS"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_avx512_popcnt_intrinsics_" >&5
+$as_echo "$pgac_cv_avx512_popcnt_intrinsics_" >&6; }
+if test x"$pgac_cv_avx512_popcnt_intrinsics_" = x"yes"; then
+  CFLAGS_AVX512_POPCNT=""
+  pgac_avx512_popcnt_intrinsics=yes
+fi
+
+if test x"$pgac_avx512_popcnt_intrinsics" != x"yes"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for _mm512_popcnt_epi64 with CFLAGS=-mavx512vpopcntdq -mavx512f" >&5
+$as_echo_n "checking for _mm512_popcnt_epi64 with CFLAGS=-mavx512vpopcntdq -mavx512f... " >&6; }
+if ${pgac_cv_avx512_popcnt_intrinsics__mavx512vpopcntdq__mavx512f+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  pgac_save_CFLAGS=$CFLAGS
+CFLAGS="$pgac_save_CFLAGS -mavx512vpopcntdq -mavx512f"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <immintrin.h>
+#include <stdint.h>
+int
+main ()
+{
+__m512i tmp __attribute__((aligned(64)));
+   __m512i input = _mm512_setzero_si512();
+   __m512i output = _mm512_popcnt_epi64(input);
+   uint64_t cnt = 999;
+   _mm512_store_si512(&tmp, output);
+   cnt = _mm512_reduce_add_epi64(tmp);
+   /* return computed value, to prevent the above being optimized away */
+   return cnt == 0;
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  pgac_cv_avx512_popcnt_intrinsics__mavx512vpopcntdq__mavx512f=yes
+else
+  pgac_cv_avx512_popcnt_intrinsics__mavx512vpopcntdq__mavx512f=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+CFLAGS="$pgac_save_CFLAGS"
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_avx512_popcnt_intrinsics__mavx512vpopcntdq__mavx512f" >&5
+$as_echo "$pgac_cv_avx512_popcnt_intrinsics__mavx512vpopcntdq__mavx512f" >&6; }
+if test x"$pgac_cv_avx512_popcnt_intrinsics__mavx512vpopcntdq__mavx512f" = x"yes"; then
+  CFLAGS_AVX512_POPCNT="-mavx512vpopcntdq -mavx512f"
+  pgac_avx512_popcnt_intrinsics=yes
+fi
+
+fi
+
+
 # Check for Intel SSE 4.2 intrinsics to do CRC calculations.
 #
 # First check if the _mm_crc32_u8 and _mm_crc32_u64 intrinsics can be used
diff --git a/configure.ac b/configure.ac
index 52fd7af446..ae110e9d59 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2067,6 +2067,18 @@ if test x"$pgac_cv__get_cpuid" = x"yes"; then
   AC_DEFINE(HAVE__GET_CPUID, 1, [Define to 1 if you have __get_cpuid.])
 fi
 
+# Check for x86 cpuid_count instruction
+AC_CACHE_CHECK([for __get_cpuid_count], [pgac_cv__get_cpuid_count],
+[AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <cpuid.h>],
+  [[unsigned int exx[4] = {0, 0, 0, 0};
+  __get_cpuid_count(7, 0, &exx[0], &exx[1], &exx[2], &exx[3]);
+  ]])],
+  [pgac_cv__get_cpuid_count="yes"],
+  [pgac_cv__get_cpuid_count="no"])])
+if test x"$pgac_cv__get_cpuid_count" = x"yes"; then
+  AC_DEFINE(HAVE__GET_CPUID_COUNT, 1, [Define to 1 if you have __get_cpuid.])
+fi
+
 AC_CACHE_CHECK([for __cpuid], [pgac_cv__cpuid],
 [AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <intrin.h>],
   [[unsigned int exx[4] = {0, 0, 0, 0};
@@ -2078,6 +2090,36 @@ if test x"$pgac_cv__cpuid" = x"yes"; then
   AC_DEFINE(HAVE__CPUID, 1, [Define to 1 if you have __cpuid.])
 fi
 
+AC_CACHE_CHECK([for __cpuidex], [pgac_cv__cpuidex],
+[AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <intrin.h>],
+  [[unsigned int exx[4] = {0, 0, 0, 0};
+  __get_cpuidex(exx[0], 7, 0);
+  ]])],
+  [pgac_cv__cpuidex="yes"],
+  [pgac_cv__cpuidex="no"])])
+if test x"$pgac_cv__cpuidex" = x"yes"; then
+  AC_DEFINE(HAVE__CPUIDEX, 1, [Define to 1 if you have __cpuidex.])
+fi
+
+AC_CACHE_CHECK([for __immintrin], [pgac_cv__immintrin],
+[AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <immintrin.h>],
+  [[/* Don't exclude code so added return. */
+    return 1701;
+  ]])],
+  [pgac_cv__immintrin="yes"],
+  [pgac_cv__immintrin="no"])])
+if test x"$pgac_cv__immintrin" = x"yes"; then
+  AC_DEFINE(HAVE__IMMINTRIN, 1, [Define to 1 if you have immintrin.])
+fi
+
+# Check for Intel AVX512 intrinsics to do POPCNT calculations.
+#
+PGAC_AVX512_POPCNT_INTRINSICS([])
+if test x"$pgac_avx512_popcnt_intrinsics" != x"yes"; then
+  PGAC_AVX512_POPCNT_INTRINSICS([-mavx512vpopcntdq -mavx512f])
+fi
+AC_SUBST(CFLAGS_AVX512_POPCNT)
+
 # Check for Intel SSE 4.2 intrinsics to do CRC calculations.
 #
 # First check if the _mm_crc32_u8 and _mm_crc32_u64 intrinsics can be used
diff --git a/meson.build b/meson.build
index 8ed51b6aae..1e7a4dc942 100644
--- a/meson.build
+++ b/meson.build
@@ -1773,6 +1773,45 @@ elif cc.links('''
 endif
 
 
+# XXX: The configure.ac check for __cpuidex() is broken, we don't copy that
+# here. To prevent problems due to two detection methods working, stop
+# checking after one.
+if cc.links('''
+    #include <cpuid.h>
+    int main(int arg, char **argv)
+    {
+        unsigned int exx[4] = {0, 0, 0, 0};
+        __get_cpuid_count(7, 0, &exx[0], &exx[1], &exx[2], &exx[3]);
+    }
+    ''', name: '__get_cpuid_count',
+    args: test_c_args)
+  cdata.set('HAVE__GET_CPUID_COUNT', 1)
+elif cc.links('''
+    #include <intrin.h>
+    int main(int arg, char **argv)
+    {
+        unsigned int exx[4] = {0, 0, 0, 0};
+        __cpuidex(exx, 7, 0);
+    }
+    ''', name: '__cpuidex',
+    args: test_c_args)
+  cdata.set('HAVE__CPUIDEX', 1)
+endif
+
+
+# Check for header immintrin.h
+if cc.links('''
+    #include <immintrin.h>
+    int main(int arg, char **argv)
+    {
+      return 1701;
+    }
+    ''', name: '__immintrin',
+    args: test_c_args)
+  cdata.set('HAVE__IMMINTRIN', 1)
+endif
+
+
 # Defend against clang being used on x86-32 without SSE2 enabled.  As current
 # versions of clang do not understand -fexcess-precision=standard, the use of
 # x87 floating point operations leads to problems like isinf possibly returning
@@ -2146,6 +2185,32 @@ elif host_cpu == 'ppc' or host_cpu == 'ppc64'
   endif
 endif
 
+###############################################################
+# AVX 512 POPCNT Intrinsic check
+###############################################################
+have_avx512_popcnt = false
+cflags_avx512_popcnt = []
+if host_cpu == 'x86_64'
+  prog = '''
+      #include <immintrin.h>
+      #include <stdint.h>
+      void main(void)
+      {
+        __m512i tmp __attribute__((aligned(64)));
+        __m512i input = _mm512_setzero_si512();
+        __m512i output = _mm512_popcnt_epi64(input);
+        uint64_t cnt = 999;
+        _mm512_store_si512(&tmp, output);
+        cnt = _mm512_reduce_add_epi64(tmp);
+        /* return computed value, to prevent the above being optimized away */
+        return cnt == 0;
+      }'''
+    if cc.links(prog, name: '_mm512_setzero_si512, _mm512_popcnt_epi64, _mm512_store_si512, and _mm512_reduce_add_epi64 with -mavx512vpopcntdq -mavx512f',
+                args: test_c_args + ['-mavx512vpopcntdq', '-mavx512f'])
+      have_avx512_popcnt = true
+      cflags_avx512_popcnt = ['-mavx512vpopcntdq', '-mavx512f']
+    endif
+endif
 
 
 ###############################################################
diff --git a/src/Makefile.global.in b/src/Makefile.global.in
index 8b3f8c24e0..089f49b7f3 100644
--- a/src/Makefile.global.in
+++ b/src/Makefile.global.in
@@ -263,6 +263,7 @@ CXXFLAGS_SL_MODULE = @CXXFLAGS_SL_MODULE@
 CFLAGS_UNROLL_LOOPS = @CFLAGS_UNROLL_LOOPS@
 CFLAGS_VECTORIZE = @CFLAGS_VECTORIZE@
 CFLAGS_CRC = @CFLAGS_CRC@
+CFLAGS_AVX512_POPCNT = @CFLAGS_AVX512_POPCNT@
 PERMIT_DECLARATION_AFTER_STATEMENT = @PERMIT_DECLARATION_AFTER_STATEMENT@
 CXXFLAGS = @CXXFLAGS@
 
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 07e73567dc..20e14c6499 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -555,6 +555,12 @@
 /* Define to 1 if you have __get_cpuid. */
 #undef HAVE__GET_CPUID
 
+/* Define to 1 if you have __get_cpuid_count. */
+#undef HAVE__GET_CPUID_COUNT
+
+/* Define to 1 if you have  immintrin. */
+#undef HAVE__IMMINTRIN
+
 /* Define to 1 if your compiler understands _Static_assert. */
 #undef HAVE__STATIC_ASSERT
 
diff --git a/src/makefiles/meson.build b/src/makefiles/meson.build
index b0f4178b3d..ee3647282e 100644
--- a/src/makefiles/meson.build
+++ b/src/makefiles/meson.build
@@ -100,6 +100,7 @@ pgxs_kv = {
     ' '.join(cflags_no_decl_after_statement),
 
   'CFLAGS_CRC': ' '.join(cflags_crc),
+  'CFLAGS_AVX512_POPCNT': ' '.join(cflags_avx512_popcnt),
   'CFLAGS_UNROLL_LOOPS': ' '.join(unroll_loops_cflags),
   'CFLAGS_VECTORIZE': ' '.join(vectorize_cflags),
 
diff --git a/src/port/Makefile b/src/port/Makefile
index dcc8737e68..6a01a7d89a 100644
--- a/src/port/Makefile
+++ b/src/port/Makefile
@@ -87,6 +87,11 @@ pg_crc32c_sse42.o: CFLAGS+=$(CFLAGS_CRC)
 pg_crc32c_sse42_shlib.o: CFLAGS+=$(CFLAGS_CRC)
 pg_crc32c_sse42_srv.o: CFLAGS+=$(CFLAGS_CRC)
 
+# Newer Intel processors can use AVX-512 POPCNT Capabilities (01/30/2024)
+pg_bitutils.o: CFLAGS+=$(CFLAGS_AVX512_POPCNT)
+pg_bitutils_shlib.o: CFLAGS+=$(CFLAGS_AVX512_POPCNT)
+pg_bitutils_srv.o:CFLAGS+=$(CFLAGS_AVX512_POPCNT)
+
 # all versions of pg_crc32c_armv8.o need CFLAGS_CRC
 pg_crc32c_armv8.o: CFLAGS+=$(CFLAGS_CRC)
 pg_crc32c_armv8_shlib.o: CFLAGS+=$(CFLAGS_CRC)
diff --git a/src/port/meson.build b/src/port/meson.build
index 69b30ab21b..1c48a3b07e 100644
--- a/src/port/meson.build
+++ b/src/port/meson.build
@@ -184,6 +184,7 @@ foreach name, opts : pgport_variants
       link_with: cflag_libs,
       c_pch: pch_c_h,
       kwargs: opts + {
+        'c_args': opts.get('c_args', []) + cflags_avx512_popcnt,
         'dependencies': opts['dependencies'] + [ssl],
       }
     )
diff --git a/src/port/pg_bitutils.c b/src/port/pg_bitutils.c
index 640a89561a..cda41e7438 100644
--- a/src/port/pg_bitutils.c
+++ b/src/port/pg_bitutils.c
@@ -15,10 +15,15 @@
 #ifdef HAVE__GET_CPUID
 #include <cpuid.h>
 #endif
+
 #ifdef HAVE__CPUID
 #include <intrin.h>
 #endif
 
+#if defined(HAVE__IMMINTRIN)
+#include <immintrin.h>
+#endif
+
 #include "port/pg_bitutils.h"
 
 
@@ -110,11 +115,15 @@ static int	pg_popcount64_slow(uint64 word);
 static bool pg_popcount_available(void);
 static int	pg_popcount32_choose(uint32 word);
 static int	pg_popcount64_choose(uint64 word);
+static uint64 pg_popcount512_choose(const char *buf, int bytes);
 static int	pg_popcount32_fast(uint32 word);
 static int	pg_popcount64_fast(uint64 word);
+static uint64 pg_popcount512_fast(const char *buf, int bytes);
+static uint64 pg_popcount512_slow(const char *buf, int bytes);
 
 int			(*pg_popcount32) (uint32 word) = pg_popcount32_choose;
 int			(*pg_popcount64) (uint64 word) = pg_popcount64_choose;
+uint64		(*pg_popcount512) (const char *buf, int bytes) = pg_popcount512_choose;
 #endif							/* TRY_POPCNT_FAST */
 
 #ifdef TRY_POPCNT_FAST
@@ -138,6 +147,50 @@ pg_popcount_available(void)
 	return (exx[2] & (1 << 23)) != 0;	/* POPCNT */
 }
 
+/*
+ * Return true if CPUID indicates that the AVX512_POPCNT instruction is
+ * available. This is similar to the method above; see
+ * https://en.wikipedia.org/wiki/CPUID#EAX=7,_ECX=0:_Extended_Features
+ *
+ * Finally, we make sure the xgetbv result is consistent with the CPUID
+ * results.
+ */
+static bool
+pg_popcount512_available(void)
+{
+#ifdef HAVE__IMMINTRIN
+	unsigned int exx[4] = {0, 0, 0, 0};
+
+	/* Check for AVX512VPOPCNTDQ and AVX512F */
+#if defined(HAVE__GET_CPUID_COUNT)
+	__get_cpuid_count(7, 0, &exx[0], &exx[1], &exx[2], &exx[3]);
+#elif defined(HAVE__CPUIDEX)
+	__cpuidex(exx, 7, 0);
+#else
+#error __get_cpuid_count or __cpuidex instruction not available
+#endif
+
+	if ((exx[2] & (0x00004000)) != 0 && (exx[1] & (0x00010000)) != 0)
+	{
+		/*
+		 * CPUID succeeded, does the current running OS support the
+		 * ZMM registers which are required for AVX512? This check is
+		 * required to make sure an old OS on a new CPU is correctly
+		 * checked or a VM hypervisor is not excluding AVX512 ZMM
+		 * support in the VM; see "5.1.9 Detection of AVX Instructions"
+		 * https://www.intel.com/content/www/us/en/content-details/671488/intel-64-and-ia-32-architectures-optimization-reference-manual-volume-1.html
+		 */
+		uint64		xcr = 0;
+		uint32		high;
+		uint32		low;
+
+__asm__ __volatile__("xgetbv\t\n":"=a"(low), "=d"(high):"c"(xcr));
+		return (low & 0xE0) != 0;
+	}							/* POPCNT 512 */
+#endif							/* HAVE__IMMINTRIN */
+	return false;
+}
+
 /*
  * These functions get called on the first call to pg_popcount32 etc.
  * They detect whether we can use the asm implementations, and replace
@@ -178,6 +231,17 @@ pg_popcount64_choose(uint64 word)
 	return pg_popcount64(word);
 }
 
+static uint64
+pg_popcount512_choose(const char *buf, int bytes)
+{
+	if (pg_popcount512_available())
+		pg_popcount512 = pg_popcount512_fast;
+	else
+		pg_popcount512 = pg_popcount512_slow;
+
+	return pg_popcount512(buf, bytes);
+}
+
 /*
  * pg_popcount32_fast
  *		Return the number of 1 bits set in word
@@ -212,6 +276,33 @@ __asm__ __volatile__(" popcntq %1,%0\n":"=q"(res):"rm"(word):"cc");
 #endif
 }
 
+static uint64
+pg_popcount512_fast(const char *buf, int bytes)
+{
+	uint64		popcnt = 0;
+#ifdef HAVE__IMMINTRIN
+	__m512i		accumulator = _mm512_setzero_si512();
+
+	while (bytes >= 64)
+	{
+		const		__m512i v = _mm512_loadu_si512((const __m512i *) buf);
+		const		__m512i p = _mm512_popcnt_epi64(v);
+
+		accumulator = _mm512_add_epi64(accumulator, p);
+		bytes -= 64;
+		buf += 64;
+	}
+
+	popcnt = _mm512_reduce_add_epi64(accumulator);
+	bytes = bytes % 64;
+#endif                          /* HAVE__IMMINTRIN */
+
+	/* Process any remaining bytes */
+	while (bytes--)
+		popcnt += pg_number_of_ones[(unsigned char) *buf++];
+	return popcnt;
+}
+
 #endif							/* TRY_POPCNT_FAST */
 
 
@@ -265,6 +356,31 @@ pg_popcount64_slow(uint64 word)
 #endif							/* HAVE__BUILTIN_POPCOUNT */
 }
 
+static uint64
+pg_popcount512_slow(const char *buf, int bytes)
+{
+	uint64		popcnt = 0;
+
+	if (buf == (const char *) TYPEALIGN(8, buf))
+	{
+		const uint64 *words = (const uint64 *) buf;
+
+		while (bytes >= 8)
+		{
+			popcnt += pg_popcount64(*words++);
+			bytes -= 8;
+		}
+
+		buf = (const char *) words;
+	}
+
+	/* Process any remaining bytes */
+	while (bytes--)
+		popcnt += pg_number_of_ones[(unsigned char) *buf++];
+
+	return popcnt;
+}
+
 #ifndef TRY_POPCNT_FAST
 
 /*
@@ -286,6 +402,12 @@ pg_popcount64(uint64 word)
 	return pg_popcount64_slow(word);
 }
 
+uint64
+pg_popcount512(const char *buf, int bytes)
+{
+	return pg_popcount512_slow(buf, bytes);
+}
+
 #endif							/* !TRY_POPCNT_FAST */
 
 /*
@@ -298,19 +420,7 @@ pg_popcount(const char *buf, int bytes)
 	uint64		popcnt = 0;
 
 #if SIZEOF_VOID_P >= 8
-	/* Process in 64-bit chunks if the buffer is aligned. */
-	if (buf == (const char *) TYPEALIGN(8, buf))
-	{
-		const uint64 *words = (const uint64 *) buf;
-
-		while (bytes >= 8)
-		{
-			popcnt += pg_popcount64(*words++);
-			bytes -= 8;
-		}
-
-		buf = (const char *) words;
-	}
+	return pg_popcount512(buf, bytes);
 #else
 	/* Process in 32-bit chunks if the buffer is aligned. */
 	if (buf == (const char *) TYPEALIGN(4, buf))