[PATCH 03/14] S390: Configure check for vector support in gcc.

[Stefan Liebler <stli at linux dot vnet dot ibm dot com>]

The S390 specific test checks if the gcc has support for vector registers
by compiling an inline assembly which clobbers vector registers.
On success the macro HAVE_S390_VX_GCC_SUPPORT is defined.
This macro can be used to determine if e.g. clobbering vector registers
is allowed or not.

ChangeLog:

	* config.h.in (HAVE_S390_VX_GCC_SUPPORT): New macro undefine.
	* sysdeps/s390/configure.ac: Add test for S390 vector register
	support in gcc.
	* sysdeps/s390/configure: Regenerated.
---
 config.h.in               |  4 ++++
 sysdeps/s390/configure    | 32 ++++++++++++++++++++++++++++++++
 sysdeps/s390/configure.ac | 21 +++++++++++++++++++++
 3 files changed, 57 insertions(+)

diff --git a/config.h.in b/config.h.in
index 13c0044..0143ef4 100644
--- a/config.h.in
+++ b/config.h.in
@@ -73,6 +73,10 @@
 /* Define if assembler supports vector instructions on S390.  */
 #undef  HAVE_S390_VX_ASM_SUPPORT
 
+/* Define if gcc supports vector registers as clobbers in inline assembly
+   on S390.  */
+#undef  HAVE_S390_VX_GCC_SUPPORT
+
 /* Define if assembler supports Intel MPX.  */
 #undef  HAVE_MPX_SUPPORT
 
diff --git a/sysdeps/s390/configure b/sysdeps/s390/configure
index 0fa54c3..c9fb69c 100644
--- a/sysdeps/s390/configure
+++ b/sysdeps/s390/configure
@@ -144,6 +144,38 @@ else
 $as_echo "$as_me: WARNING: Use binutils with vector-support in order to use optimized implementations." >&2;}
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for S390 vector support in gcc" >&5
+$as_echo_n "checking for S390 vector support in gcc... " >&6; }
+if ${libc_cv_gcc_s390_vx+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  cat > conftest.c <<\EOF
+void testvecclobber ()
+{
+  __asm__ ("" : : : "v16");
+}
+EOF
+if { ac_try='${CC-cc} --shared conftest.c -o conftest.o &> /dev/null'
+  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+  (eval $ac_try) 2>&5
+  ac_status=$?
+  $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+  test $ac_status = 0; }; } ;
+then
+  libc_cv_gcc_s390_vx=yes
+else
+  libc_cv_gcc_s390_vx=no
+fi
+rm -f conftest*
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_gcc_s390_vx" >&5
+$as_echo "$libc_cv_gcc_s390_vx" >&6; }
+
+if test "$libc_cv_gcc_s390_vx" = yes ;
+then
+  $as_echo "#define HAVE_S390_VX_GCC_SUPPORT 1" >>confdefs.h
+
+fi
 
 test -n "$critic_missing" && as_fn_error $? "
 *** $critic_missing" "$LINENO" 5
diff --git a/sysdeps/s390/configure.ac b/sysdeps/s390/configure.ac
index 4da134e..1db6d84 100644
--- a/sysdeps/s390/configure.ac
+++ b/sysdeps/s390/configure.ac
@@ -64,6 +64,27 @@ else
   AC_MSG_WARN([Use binutils with vector-support in order to use optimized implementations.])
 fi
 
+AC_CACHE_CHECK(for S390 vector support in gcc, libc_cv_gcc_s390_vx, [dnl
+cat > conftest.c <<\EOF
+void testvecclobber ()
+{
+  __asm__ ("" : : : "v16");
+}
+EOF
+dnl
+dnl test, if gcc supports S390 vector registers as clobber in inline assembly
+if AC_TRY_COMMAND([${CC-cc} --shared conftest.c -o conftest.o &> /dev/null]) ;
+then
+  libc_cv_gcc_s390_vx=yes
+else
+  libc_cv_gcc_s390_vx=no
+fi
+rm -f conftest* ])
+
+if test "$libc_cv_gcc_s390_vx" = yes ;
+then
+  AC_DEFINE(HAVE_S390_VX_GCC_SUPPORT)
+fi
 
 test -n "$critic_missing" && AC_MSG_ERROR([
 *** $critic_missing])
-- 
2.3.0