Fix ./configure checks with __cpuidex() and __cpuid()

The configure checks used two incorrect functions when checking the
presence of some routines in an environment:
- __get_cpuidex() for the check of __cpuidex().
- __get_cpuid() for the check of __cpuid().
This means that Postgres has never been able to detect the presence of
these functions, impacting environments where these exist, like Windows.

Simply fixing the function name does not work.  For example, using
configure with MinGW on Windows causes the checks to detect all four of
__get_cpuid(), __get_cpuid_count(), __cpuidex() and __cpuid() to be
available, causing a compilation failure as this messes up with the
MinGW headers as we would include both <intrin.h> and <cpuid.h>.

The Postgres code expects only one in { __get_cpuid() , __cpuid() } and
one in { __get_cpuid_count() , __cpuidex() } to exist.  This commit
reshapes the configure checks to do exactly what meson is doing, which
has been working well for us: check one, then the other, but never allow
both to be detected in a given build.

The logic is wrong since 3dc2d62d0486 and 792752af4eb5 where these
checks have been introduced (the second case is most likely a copy-pasto
coming from the first case), with meson documenting that the configure
checks were broken.  As far as I can see, they are not once applied
consistently with what the code expects, but let's see if the buildfarm
has different something to say.  The comment in meson.build is adjusted
as well, to reflect the new reality.

Author: Lukas Fittl <lukas@fittl.com>
Co-authored-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/aIgwNYGVt5aRAqTJ@paquier.xyz
Backpatch-through: 13

diff --git a/configure b/configure
index d0db84867b93e90ac7357ff66bf0d92c2e5c02d4..ed5f9cafb4f3de8af987f49f4d998c2abbc6d494 100755 (executable)
--- a/configure
+++ b/configure
@@ -17565,7 +17565,7 @@ $as_echo "#define HAVE_GCC__ATOMIC_INT64_CAS 1" >>confdefs.h
 fi
 
 
-# Check for x86 cpuid instruction
+# Check for __get_cpuid() and __cpuid()
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __get_cpuid" >&5
 $as_echo_n "checking for __get_cpuid... " >&6; }
 if ${pgac_cv__get_cpuid+:} false; then :
@@ -17598,77 +17598,79 @@ if test x"$pgac_cv__get_cpuid" = x"yes"; then
 
 $as_echo "#define HAVE__GET_CPUID 1" >>confdefs.h
 
-fi
-
-{ $as_echo "$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 :
+else
+  # __cpuid()
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for __cpuid" >&5
+$as_echo_n "checking for __cpuid... " >&6; }
+if ${pgac_cv__cpuid+:} false; then :
   $as_echo_n "(cached) " >&6
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-#include <cpuid.h>
+#include <intrin.h>
 int
 main ()
 {
 unsigned int exx[4] = {0, 0, 0, 0};
-  __get_cpuid_count(7, 0, &exx[0], &exx[1], &exx[2], &exx[3]);
+    __cpuid(exx, 1);
 
   ;
   return 0;
 }
 _ACEOF
 if ac_fn_c_try_link "$LINENO"; then :
-  pgac_cv__get_cpuid_count="yes"
+  pgac_cv__cpuid="yes"
 else
-  pgac_cv__get_cpuid_count="no"
+  pgac_cv__cpuid="no"
 fi
 rm -f core conftest.err conftest.$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
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv__cpuid" >&5
+$as_echo "$pgac_cv__cpuid" >&6; }
+  if test x"$pgac_cv__cpuid" = x"yes"; then
 
-$as_echo "#define HAVE__GET_CPUID_COUNT 1" >>confdefs.h
+$as_echo "#define HAVE__CPUID 1" >>confdefs.h
 
+  fi
 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 :
+# Check for __get_cpuid_count() and __cpuidex() in a similar fashion.
+{ $as_echo "$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 <intrin.h>
+#include <cpuid.h>
 int
 main ()
 {
 unsigned int exx[4] = {0, 0, 0, 0};
-  __get_cpuid(exx[0], 1);
+  __get_cpuid_count(7, 0, &exx[0], &exx[1], &exx[2], &exx[3]);
 
   ;
   return 0;
 }
 _ACEOF
 if ac_fn_c_try_link "$LINENO"; then :
-  pgac_cv__cpuid="yes"
+  pgac_cv__get_cpuid_count="yes"
 else
-  pgac_cv__cpuid="no"
+  pgac_cv__get_cpuid_count="no"
 fi
 rm -f core conftest.err conftest.$ac_objext \
     conftest$ac_exeext conftest.$ac_ext
 fi
-{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv__cpuid" >&5
-$as_echo "$pgac_cv__cpuid" >&6; }
-if test x"$pgac_cv__cpuid" = x"yes"; then
-
-$as_echo "#define HAVE__CPUID 1" >>confdefs.h
+{ $as_echo "$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
 
-fi
+$as_echo "#define HAVE__GET_CPUID_COUNT 1" >>confdefs.h
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for __cpuidex" >&5
+else
+  # __cpuidex()
+  { $as_echo "$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
@@ -17680,7 +17682,7 @@ int
 main ()
 {
 unsigned int exx[4] = {0, 0, 0, 0};
-  __get_cpuidex(exx[0], 7, 0);
+    __cpuidex(exx, 7, 0);
 
   ;
   return 0;
@@ -17696,10 +17698,11 @@ rm -f core conftest.err conftest.$ac_objext \
 fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv__cpuidex" >&5
 $as_echo "$pgac_cv__cpuidex" >&6; }
-if test x"$pgac_cv__cpuidex" = x"yes"; then
+  if test x"$pgac_cv__cpuidex" = x"yes"; then
 
 $as_echo "#define HAVE__CPUIDEX 1" >>confdefs.h
 
+  fi
 fi
 
 # Check for XSAVE intrinsics

diff --git a/configure.ac b/configure.ac
index f3fb8794645a8de8ee5e4e4b3012f49c37a890d7..587772d2b93125feb5295dbb28b3eade10b2a9e2 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -2044,7 +2044,7 @@ PGAC_HAVE_GCC__ATOMIC_INT32_CAS
 PGAC_HAVE_GCC__ATOMIC_INT64_CAS
 
 
-# Check for x86 cpuid instruction
+# Check for __get_cpuid() and __cpuid()
 AC_CACHE_CHECK([for __get_cpuid], [pgac_cv__get_cpuid],
 [AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <cpuid.h>],
   [[unsigned int exx[4] = {0, 0, 0, 0};
@@ -2054,8 +2054,21 @@ AC_CACHE_CHECK([for __get_cpuid], [pgac_cv__get_cpuid],
   [pgac_cv__get_cpuid="no"])])
 if test x"$pgac_cv__get_cpuid" = x"yes"; then
   AC_DEFINE(HAVE__GET_CPUID, 1, [Define to 1 if you have __get_cpuid.])
+else
+  # __cpuid()
+  AC_CACHE_CHECK([for __cpuid], [pgac_cv__cpuid],
+  [AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <intrin.h>],
+    [[unsigned int exx[4] = {0, 0, 0, 0};
+    __cpuid(exx, 1);
+    ]])],
+    [pgac_cv__cpuid="yes"],
+    [pgac_cv__cpuid="no"])])
+  if test x"$pgac_cv__cpuid" = x"yes"; then
+    AC_DEFINE(HAVE__CPUID, 1, [Define to 1 if you have __cpuid.])
+  fi
 fi
 
+# Check for __get_cpuid_count() and __cpuidex() in a similar fashion.
 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};
@@ -2065,28 +2078,18 @@ AC_CACHE_CHECK([for __get_cpuid_count], [pgac_cv__get_cpuid_count],
   [pgac_cv__get_cpuid_count="no"])])
 if test x"$pgac_cv__get_cpuid_count" = x"yes"; then
   AC_DEFINE(HAVE__GET_CPUID_COUNT, 1, [Define to 1 if you have __get_cpuid_count.])
-fi
-
-AC_CACHE_CHECK([for __cpuid], [pgac_cv__cpuid],
-[AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <intrin.h>],
-  [[unsigned int exx[4] = {0, 0, 0, 0};
-  __get_cpuid(exx[0], 1);
-  ]])],
-  [pgac_cv__cpuid="yes"],
-  [pgac_cv__cpuid="no"])])
-if test x"$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"$pgac_cv__cpuidex" = x"yes"; then
-  AC_DEFINE(HAVE__CPUIDEX, 1, [Define to 1 if you have __cpuidex.])
+else
+  # __cpuidex()
+  AC_CACHE_CHECK([for __cpuidex], [pgac_cv__cpuidex],
+  [AC_LINK_IFELSE([AC_LANG_PROGRAM([#include <intrin.h>],
+    [[unsigned int exx[4] = {0, 0, 0, 0};
+    __cpuidex(exx, 7, 0);
+    ]])],
+    [pgac_cv__cpuidex="yes"],
+    [pgac_cv__cpuidex="no"])])
+  if test x"$pgac_cv__cpuidex" = x"yes"; then
+    AC_DEFINE(HAVE__CPUIDEX, 1, [Define to 1 if you have __cpuidex.])
+  fi
 fi
 
 # Check for XSAVE intrinsics

diff --git a/meson.build b/meson.build
index 21c31f05f75ad1d011a114da1e3d4e55e01f783c..36edb5a8fad5cb95ffe486ad7967128d7ebc8e31 100644 (file)
--- a/meson.build
+++ b/meson.build
@@ -1991,10 +1991,7 @@ if cc.links('''
   cdata.set('HAVE__BUILTIN_OP_OVERFLOW', 1)
 endif
 
-
-# XXX: The configure.ac check for __cpuid() is broken, we don't copy that
-# here. To prevent problems due to two detection methods working, stop
-# checking after one.
+# Check for __get_cpuid() and __cpuid().
 if cc.links('''
     #include <cpuid.h>
     int main(int arg, char **argv)