Check compiler features only for the relevant platform.

* mpi/config.links (mpi_cpu_arch): Always set for ARM.  Set for HPPA.
Set to "undefined" for unknown platforms.
(try_asm_modules): Act upon only after having detected the CPU.
* configure.ac: Move the call to config.links before the platform
specific compiler checks.  Check platform specific features only if
the platform is targeted.
--

There is no need to check x86 options if we are targeting ARM and vice
versa.  This may only introduce build problems.  With this patch the
summary output at the end of the compiler also shows more reasonable
messages.

Signed-off-by: Werner Koch <wk@gnupg.org>
(cherry picked from commit 04d478d9b0f92d80105ddaf2c011f40ae8260cfb)

2 files changed, 191 insertions, 107 deletions

diff --git a/configure.ac b/configure.ac
index c3ab96f3..1d5027ad 100644
--- a/configure.ac
+++ b/configure.ac
@@ -575,10 +575,6 @@ AC_ARG_ENABLE(padlock-support,
        	         [Disable support for the PadLock Engine of VIA processors]),
 	      padlocksupport=$enableval,padlocksupport=yes)
 AC_MSG_RESULT($padlocksupport)
-if test x"$padlocksupport" = xyes ; then
-  AC_DEFINE(ENABLE_PADLOCK_SUPPORT, 1,
-            [Enable support for the PadLock engine.])
-fi
 
 # Implementation of the --disable-aesni-support switch.
 AC_MSG_CHECKING([whether AESNI support is requested])
@@ -603,10 +599,6 @@ AC_ARG_ENABLE(drng-support,
                  [Disable support for the Intel DRNG (RDRAND instruction)]),
 	      drngsupport=$enableval,drngsupport=yes)
 AC_MSG_RESULT($drngsupport)
-if test x"$drngsupport" = xyes ; then
-  AC_DEFINE(ENABLE_DRNG_SUPPORT, 1,
-            [Enable support for Intel DRNG (RDRAND instruction).])
-fi
 
 # Implementation of the --disable-avx-support switch.
 AC_MSG_CHECKING([whether AVX support is requested])
@@ -995,19 +987,121 @@ fi
 
 
 #
+# Check whether GCC assembler supports features needed for our ARM
+# implementations.  This needs to be done before setting up the
+# assembler stuff.
+#
+AC_CACHE_CHECK([whether GCC assembler is compatible for ARM assembly implementations],
+       [gcry_cv_gcc_arm_platform_as_ok],
+       [gcry_cv_gcc_arm_platform_as_ok=no
+        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+          [[__asm__(
+                /* Test if assembler supports UAL syntax.  */
+                ".syntax unified\n\t"
+                ".arm\n\t" /* our assembly code is in ARM mode  */
+                /* Following causes error if assembler ignored '.syntax unified'.  */
+                "asmfunc:\n\t"
+                "add %r0, %r0, %r4, ror #12;\n\t"
+
+                /* Test if '.type' and '.size' are supported.  */
+                ".size asmfunc,.-asmfunc;\n\t"
+                ".type asmfunc,%function;\n\t"
+            );]])],
+          [gcry_cv_gcc_arm_platform_as_ok=yes])])
+if test "$gcry_cv_gcc_arm_platform_as_ok" = "yes" ; then
+   AC_DEFINE(HAVE_COMPATIBLE_GCC_ARM_PLATFORM_AS,1,
+     [Defined if underlying assembler is compatible with ARM assembly implementations])
+fi
+
+
+#
+# Check whether underscores in symbols are required.  This needs to be
+# done before setting up the assembler stuff.
+#
+GNUPG_SYS_SYMBOL_UNDERSCORE()
+
+
+#################################
+####                         ####
+#### Setup assembler stuff.  ####
+#### Define mpi_cpu_arch.    ####
+####                         ####
+#################################
+AC_ARG_ENABLE(mpi-path,
+              AC_HELP_STRING([--enable-mpi-path=EXTRA_PATH],
+	      [prepend EXTRA_PATH to list of CPU specific optimizations]),
+	      mpi_extra_path="$enableval",mpi_extra_path="")
+AC_MSG_CHECKING(architecture and mpi assembler functions)
+if test -f $srcdir/mpi/config.links ; then
+    . $srcdir/mpi/config.links
+    AC_CONFIG_LINKS("$mpi_ln_list")
+    ac_cv_mpi_sflags="$mpi_sflags"
+    AC_MSG_RESULT($mpi_cpu_arch)
+else
+    AC_MSG_RESULT(failed)
+    AC_MSG_ERROR([mpi/config.links missing!])
+fi
+MPI_SFLAGS="$ac_cv_mpi_sflags"
+AC_SUBST(MPI_SFLAGS)
+
+AM_CONDITIONAL(MPI_MOD_ASM_MPIH_ADD1, test "$mpi_mod_asm_mpih_add1" = yes)
+AM_CONDITIONAL(MPI_MOD_ASM_MPIH_SUB1, test "$mpi_mod_asm_mpih_sub1" = yes)
+AM_CONDITIONAL(MPI_MOD_ASM_MPIH_MUL1, test "$mpi_mod_asm_mpih_mul1" = yes)
+AM_CONDITIONAL(MPI_MOD_ASM_MPIH_MUL2, test "$mpi_mod_asm_mpih_mul2" = yes)
+AM_CONDITIONAL(MPI_MOD_ASM_MPIH_MUL3, test "$mpi_mod_asm_mpih_mul3" = yes)
+AM_CONDITIONAL(MPI_MOD_ASM_MPIH_LSHIFT, test "$mpi_mod_asm_mpih_lshift" = yes)
+AM_CONDITIONAL(MPI_MOD_ASM_MPIH_RSHIFT, test "$mpi_mod_asm_mpih_rshift" = yes)
+AM_CONDITIONAL(MPI_MOD_ASM_UDIV, test "$mpi_mod_asm_udiv" = yes)
+AM_CONDITIONAL(MPI_MOD_ASM_UDIV_QRNND, test "$mpi_mod_asm_udiv_qrnnd" = yes)
+AM_CONDITIONAL(MPI_MOD_C_MPIH_ADD1, test "$mpi_mod_c_mpih_add1" = yes)
+AM_CONDITIONAL(MPI_MOD_C_MPIH_SUB1, test "$mpi_mod_c_mpih_sub1" = yes)
+AM_CONDITIONAL(MPI_MOD_C_MPIH_MUL1, test "$mpi_mod_c_mpih_mul1" = yes)
+AM_CONDITIONAL(MPI_MOD_C_MPIH_MUL2, test "$mpi_mod_c_mpih_mul2" = yes)
+AM_CONDITIONAL(MPI_MOD_C_MPIH_MUL3, test "$mpi_mod_c_mpih_mul3" = yes)
+AM_CONDITIONAL(MPI_MOD_C_MPIH_LSHIFT, test "$mpi_mod_c_mpih_lshift" = yes)
+AM_CONDITIONAL(MPI_MOD_C_MPIH_RSHIFT, test "$mpi_mod_c_mpih_rshift" = yes)
+AM_CONDITIONAL(MPI_MOD_C_UDIV, test "$mpi_mod_c_udiv" = yes)
+AM_CONDITIONAL(MPI_MOD_C_UDIV_QRNND, test "$mpi_mod_c_udiv_qrnnd" = yes)
+
+# Reset non applicable feature flags.
+if test "$mpi_cpu_arch" != "x86" ; then
+   aesnisupport="n/a"
+   pclmulsupport="n/a"
+   avxsupport="n/a"
+   avx2support="n/a"
+   padlocksupport="n/a"
+   drngsupport="n/a"
+fi
+
+if test "$mpi_cpu_arch" != "arm" ; then
+   neonsupport="n/a"
+fi
+
+
+#############################################
+####                                     ####
+#### Platform specific compiler checks.  ####
+####                                     ####
+#############################################
+
+#
 # Check whether GCC inline assembler supports SSSE3 instructions
 # This is required for the AES-NI instructions.
 #
 AC_CACHE_CHECK([whether GCC inline assembler supports SSSE3 instructions],
        [gcry_cv_gcc_inline_asm_ssse3],
-       [gcry_cv_gcc_inline_asm_ssse3=no
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+       [if test "$mpi_cpu_arch" != "x86" ; then
+          gcry_cv_gcc_inline_asm_ssse3="n/a"
+        else
+          gcry_cv_gcc_inline_asm_ssse3=no
+          AC_COMPILE_IFELSE([AC_LANG_SOURCE(
           [[static unsigned char be_mask[16] __attribute__ ((aligned (16))) =
               { 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 };
             void a(void) {
               __asm__("pshufb %[mask], %%xmm2\n\t"::[mask]"m"(*be_mask):);
             }]])],
-          [gcry_cv_gcc_inline_asm_ssse3=yes])])
+          [gcry_cv_gcc_inline_asm_ssse3=yes])
+        fi])
 if test "$gcry_cv_gcc_inline_asm_ssse3" = "yes" ; then
    AC_DEFINE(HAVE_GCC_INLINE_ASM_SSSE3,1,
      [Defined if inline assembler supports SSSE3 instructions])
@@ -1019,12 +1113,16 @@ fi
 #
 AC_CACHE_CHECK([whether GCC inline assembler supports PCLMUL instructions],
        [gcry_cv_gcc_inline_asm_pclmul],
-       [gcry_cv_gcc_inline_asm_pclmul=no
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+       [if test "$mpi_cpu_arch" != "x86" ; then
+          gcry_cv_gcc_inline_asm_pclmul="n/a"
+        else
+          gcry_cv_gcc_inline_asm_pclmul=no
+          AC_COMPILE_IFELSE([AC_LANG_SOURCE(
           [[void a(void) {
               __asm__("pclmulqdq \$0, %%xmm1, %%xmm3\n\t":::"cc");
             }]])],
-          [gcry_cv_gcc_inline_asm_pclmul=yes])])
+          [gcry_cv_gcc_inline_asm_pclmul=yes])
+        fi])
 if test "$gcry_cv_gcc_inline_asm_pclmul" = "yes" ; then
    AC_DEFINE(HAVE_GCC_INLINE_ASM_PCLMUL,1,
      [Defined if inline assembler supports PCLMUL instructions])
@@ -1036,12 +1134,16 @@ fi
 #
 AC_CACHE_CHECK([whether GCC inline assembler supports AVX instructions],
        [gcry_cv_gcc_inline_asm_avx],
-       [gcry_cv_gcc_inline_asm_avx=no
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+       [if test "$mpi_cpu_arch" != "x86" ; then
+          gcry_cv_gcc_inline_asm_avx="n/a"
+        else
+          gcry_cv_gcc_inline_asm_avx=no
+          AC_COMPILE_IFELSE([AC_LANG_SOURCE(
           [[void a(void) {
               __asm__("xgetbv; vaesdeclast (%[mem]),%%xmm0,%%xmm7\n\t"::[mem]"r"(0):);
             }]])],
-          [gcry_cv_gcc_inline_asm_avx=yes])])
+          [gcry_cv_gcc_inline_asm_avx=yes])
+        fi])
 if test "$gcry_cv_gcc_inline_asm_avx" = "yes" ; then
    AC_DEFINE(HAVE_GCC_INLINE_ASM_AVX,1,
      [Defined if inline assembler supports AVX instructions])
@@ -1053,12 +1155,16 @@ fi
 #
 AC_CACHE_CHECK([whether GCC inline assembler supports AVX2 instructions],
        [gcry_cv_gcc_inline_asm_avx2],
-       [gcry_cv_gcc_inline_asm_avx2=no
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+       [if test "$mpi_cpu_arch" != "x86" ; then
+          gcry_cv_gcc_inline_asm_avx2="n/a"
+        else
+          gcry_cv_gcc_inline_asm_avx2=no
+          AC_COMPILE_IFELSE([AC_LANG_SOURCE(
           [[void a(void) {
               __asm__("xgetbv; vpbroadcastb %%xmm7,%%ymm1\n\t":::"cc");
             }]])],
-          [gcry_cv_gcc_inline_asm_avx2=yes])])
+          [gcry_cv_gcc_inline_asm_avx2=yes])
+        fi])
 if test "$gcry_cv_gcc_inline_asm_avx2" = "yes" ; then
    AC_DEFINE(HAVE_GCC_INLINE_ASM_AVX2,1,
      [Defined if inline assembler supports AVX2 instructions])
@@ -1070,12 +1176,16 @@ fi
 #
 AC_CACHE_CHECK([whether GCC inline assembler supports BMI2 instructions],
        [gcry_cv_gcc_inline_asm_bmi2],
-       [gcry_cv_gcc_inline_asm_bmi2=no
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+       [if test "$mpi_cpu_arch" != "x86" ; then
+          gcry_cv_gcc_inline_asm_bmi2="n/a"
+        else
+          gcry_cv_gcc_inline_asm_bmi2=no
+          AC_COMPILE_IFELSE([AC_LANG_SOURCE(
           [[void a(void) {
               __asm__("rorxl \$23, %%eax, %%edx\\n\\t":::"memory");
             }]])],
-          [gcry_cv_gcc_inline_asm_bmi2=yes])])
+          [gcry_cv_gcc_inline_asm_bmi2=yes])
+        fi])
 if test "$gcry_cv_gcc_inline_asm_bmi2" = "yes" ; then
    AC_DEFINE(HAVE_GCC_INLINE_ASM_BMI2,1,
      [Defined if inline assembler supports BMI2 instructions])
@@ -1120,8 +1230,11 @@ fi
 if test $amd64_as_feature_detection = yes; then
   AC_CACHE_CHECK([whether GCC assembler is compatible for amd64 assembly implementations],
        [gcry_cv_gcc_amd64_platform_as_ok],
-       [gcry_cv_gcc_amd64_platform_as_ok=no
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+       [if test "$mpi_cpu_arch" != "x86" ; then
+          gcry_cv_gcc_amd64_platform_as_ok="n/a"
+        else
+          gcry_cv_gcc_amd64_platform_as_ok=no
+          AC_COMPILE_IFELSE([AC_LANG_SOURCE(
           [[__asm__(
                 /* Test if '.type' and '.size' are supported.  */
                 /* These work only on ELF targets. */
@@ -1137,7 +1250,8 @@ if test $amd64_as_feature_detection = yes; then
 		 * to be disable on this machine. */
 		"xorl \$(123456789/12345678), %ebp;\n\t"
             );]])],
-          [gcry_cv_gcc_amd64_platform_as_ok=yes])])
+          [gcry_cv_gcc_amd64_platform_as_ok=yes])
+        fi])
   if test "$gcry_cv_gcc_amd64_platform_as_ok" = "yes" ; then
      AC_DEFINE(HAVE_COMPATIBLE_GCC_AMD64_PLATFORM_AS,1,
               [Defined if underlying assembler is compatible with amd64 assembly implementations])
@@ -1151,8 +1265,11 @@ fi
 #
 AC_CACHE_CHECK([whether GCC assembler is compatible for Intel syntax assembly implementations],
        [gcry_cv_gcc_platform_as_ok_for_intel_syntax],
-       [gcry_cv_gcc_platform_as_ok_for_intel_syntax=no
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+       [if test "$mpi_cpu_arch" != "x86" ; then
+          gcry_cv_gcc_platform_as_ok_for_intel_syntax="n/a"
+        else
+          gcry_cv_gcc_platform_as_ok_for_intel_syntax=no
+          AC_COMPILE_IFELSE([AC_LANG_SOURCE(
           [[__asm__(
                 ".intel_syntax noprefix\n\t"
                 "pxor xmm1, xmm7;\n\t"
@@ -1172,7 +1289,8 @@ AC_CACHE_CHECK([whether GCC assembler is compatible for Intel syntax assembly im
                 "add VAL_A, VAL_B;\n\t"
                 "add VAL_B, 0b10101;\n\t"
             );]])],
-          [gcry_cv_gcc_platform_as_ok_for_intel_syntax=yes])])
+          [gcry_cv_gcc_platform_as_ok_for_intel_syntax=yes])
+        fi])
 if test "$gcry_cv_gcc_platform_as_ok_for_intel_syntax" = "yes" ; then
   AC_DEFINE(HAVE_INTEL_SYNTAX_PLATFORM_AS,1,
             [Defined if underlying assembler is compatible with Intel syntax assembly implementations])
@@ -1184,7 +1302,10 @@ fi
 #
 AC_CACHE_CHECK([whether compiler is configured for ARMv6 or newer architecture],
        [gcry_cv_cc_arm_arch_is_v6],
-       [AC_EGREP_CPP(yes,
+       [if test "$mpi_cpu_arch" != "arm" ; then
+          gcry_cv_cc_arm_arch_is_v6="n/a"
+        else
+          AC_EGREP_CPP(yes,
           [#if defined(__arm__) && \
              ((defined(__ARM_ARCH) && __ARM_ARCH >= 6) \
              || defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \
@@ -1195,7 +1316,8 @@ AC_CACHE_CHECK([whether compiler is configured for ARMv6 or newer architecture],
              || defined(__ARM_ARCH_7EM__))
             yes
            #endif
-          ], gcry_cv_cc_arm_arch_is_v6=yes, gcry_cv_cc_arm_arch_is_v6=no)])
+          ], gcry_cv_cc_arm_arch_is_v6=yes, gcry_cv_cc_arm_arch_is_v6=no)
+        fi])
 if test "$gcry_cv_cc_arm_arch_is_v6" = "yes" ; then
    AC_DEFINE(HAVE_ARM_ARCH_V6,1,
      [Defined if ARM architecture is v6 or newer])
@@ -1207,8 +1329,11 @@ fi
 #
 AC_CACHE_CHECK([whether GCC inline assembler supports NEON instructions],
        [gcry_cv_gcc_inline_asm_neon],
-       [gcry_cv_gcc_inline_asm_neon=no
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
+       [if test "$mpi_cpu_arch" != "arm" ; then
+          gcry_cv_gcc_inline_asm_neon="n/a"
+        else
+          gcry_cv_gcc_inline_asm_neon=no
+          AC_COMPILE_IFELSE([AC_LANG_SOURCE(
           [[__asm__(
                 ".syntax unified\n\t"
                 ".thumb\n\t"
@@ -1219,40 +1344,14 @@ AC_CACHE_CHECK([whether GCC inline assembler supports NEON instructions],
                 "vadd.s64 %d3, %d2, %d3;\n\t"
                 );
             ]])],
-          [gcry_cv_gcc_inline_asm_neon=yes])])
+          [gcry_cv_gcc_inline_asm_neon=yes])
+        fi])
 if test "$gcry_cv_gcc_inline_asm_neon" = "yes" ; then
    AC_DEFINE(HAVE_GCC_INLINE_ASM_NEON,1,
      [Defined if inline assembler supports NEON instructions])
 fi
 
 
-#
-# Check whether GCC assembler supports features needed for our ARM
-# implementations
-#
-AC_CACHE_CHECK([whether GCC assembler is compatible for ARM assembly implementations],
-       [gcry_cv_gcc_arm_platform_as_ok],
-       [gcry_cv_gcc_arm_platform_as_ok=no
-        AC_COMPILE_IFELSE([AC_LANG_SOURCE(
-          [[__asm__(
-                /* Test if assembler supports UAL syntax.  */
-                ".syntax unified\n\t"
-                ".arm\n\t" /* our assembly code is in ARM mode  */
-                /* Following causes error if assembler ignored '.syntax unified'.  */
-                "asmfunc:\n\t"
-                "add %r0, %r0, %r4, ror #12;\n\t"
-
-                /* Test if '.type' and '.size' are supported.  */
-                ".size asmfunc,.-asmfunc;\n\t"
-                ".type asmfunc,%function;\n\t"
-            );]])],
-          [gcry_cv_gcc_arm_platform_as_ok=yes])])
-if test "$gcry_cv_gcc_arm_platform_as_ok" = "yes" ; then
-   AC_DEFINE(HAVE_COMPATIBLE_GCC_ARM_PLATFORM_AS,1,
-     [Defined if underlying assembler is compatible with ARM assembly implementations])
-fi
-
-
 #######################################
 #### Checks for library functions. ####
 #######################################
@@ -1368,48 +1467,8 @@ fi
 
 
 #
-# Setup assembler stuff.
-#
-# Note that config.links also defines mpi_cpu_arch, which is required
-# later on.
+# Other defines
 #
-GNUPG_SYS_SYMBOL_UNDERSCORE()
-AC_ARG_ENABLE(mpi-path,
-              AC_HELP_STRING([--enable-mpi-path=EXTRA_PATH],
-	      [prepend EXTRA_PATH to list of CPU specific optimizations]),
-	      mpi_extra_path="$enableval",mpi_extra_path="")
-AC_MSG_CHECKING(for mpi assembler functions)
-if test -f $srcdir/mpi/config.links ; then
-    . $srcdir/mpi/config.links
-    AC_CONFIG_LINKS("$mpi_ln_list")
-    ac_cv_mpi_sflags="$mpi_sflags"
-    AC_MSG_RESULT(done)
-else
-    AC_MSG_RESULT(failed)
-    AC_MSG_ERROR([mpi/config.links missing!])
-fi
-MPI_SFLAGS="$ac_cv_mpi_sflags"
-AC_SUBST(MPI_SFLAGS)
-
-AM_CONDITIONAL(MPI_MOD_ASM_MPIH_ADD1, test "$mpi_mod_asm_mpih_add1" = yes)
-AM_CONDITIONAL(MPI_MOD_ASM_MPIH_SUB1, test "$mpi_mod_asm_mpih_sub1" = yes)
-AM_CONDITIONAL(MPI_MOD_ASM_MPIH_MUL1, test "$mpi_mod_asm_mpih_mul1" = yes)
-AM_CONDITIONAL(MPI_MOD_ASM_MPIH_MUL2, test "$mpi_mod_asm_mpih_mul2" = yes)
-AM_CONDITIONAL(MPI_MOD_ASM_MPIH_MUL3, test "$mpi_mod_asm_mpih_mul3" = yes)
-AM_CONDITIONAL(MPI_MOD_ASM_MPIH_LSHIFT, test "$mpi_mod_asm_mpih_lshift" = yes)
-AM_CONDITIONAL(MPI_MOD_ASM_MPIH_RSHIFT, test "$mpi_mod_asm_mpih_rshift" = yes)
-AM_CONDITIONAL(MPI_MOD_ASM_UDIV, test "$mpi_mod_asm_udiv" = yes)
-AM_CONDITIONAL(MPI_MOD_ASM_UDIV_QRNND, test "$mpi_mod_asm_udiv_qrnnd" = yes)
-AM_CONDITIONAL(MPI_MOD_C_MPIH_ADD1, test "$mpi_mod_c_mpih_add1" = yes)
-AM_CONDITIONAL(MPI_MOD_C_MPIH_SUB1, test "$mpi_mod_c_mpih_sub1" = yes)
-AM_CONDITIONAL(MPI_MOD_C_MPIH_MUL1, test "$mpi_mod_c_mpih_mul1" = yes)
-AM_CONDITIONAL(MPI_MOD_C_MPIH_MUL2, test "$mpi_mod_c_mpih_mul2" = yes)
-AM_CONDITIONAL(MPI_MOD_C_MPIH_MUL3, test "$mpi_mod_c_mpih_mul3" = yes)
-AM_CONDITIONAL(MPI_MOD_C_MPIH_LSHIFT, test "$mpi_mod_c_mpih_lshift" = yes)
-AM_CONDITIONAL(MPI_MOD_C_MPIH_RSHIFT, test "$mpi_mod_c_mpih_rshift" = yes)
-AM_CONDITIONAL(MPI_MOD_C_UDIV, test "$mpi_mod_c_udiv" = yes)
-AM_CONDITIONAL(MPI_MOD_C_UDIV_QRNND, test "$mpi_mod_c_udiv_qrnnd" = yes)
-
 if test mym4_isgit = "yes"; then
     AC_DEFINE(IS_DEVELOPMENT_VERSION,1,
               [Defined if this is not a regular release])
@@ -1538,6 +1597,14 @@ if test x"$neonsupport" = xyes ; then
   AC_DEFINE(ENABLE_NEON_SUPPORT,1,
             [Enable support for ARM NEON instructions.])
 fi
+if test x"$padlocksupport" = xyes ; then
+  AC_DEFINE(ENABLE_PADLOCK_SUPPORT, 1,
+            [Enable support for the PadLock engine.])
+fi
+if test x"$drngsupport" = xyes ; then
+  AC_DEFINE(ENABLE_DRNG_SUPPORT, 1,
+            [Enable support for Intel DRNG (RDRAND instruction).])
+fi
 
 
 # Define conditional sources and config.h symbols depending on the
diff --git a/mpi/config.links b/mpi/config.links
index a79b03ba..57e6c2a0 100644
--- a/mpi/config.links
+++ b/mpi/config.links
@@ -21,6 +21,10 @@
 # sourced by ../configure to get the list of files to link
 # this should set $mpi_ln_list.
 # Note: this is called from the above directory.
+#
+# Reguired variables:
+#  $ac_cv_sys_symbol_underscore
+#  $gcry_cv_gcc_arm_platform_as_ok
 
 mpi_sflags=
 mpi_extra_modules=
@@ -39,7 +43,6 @@ mpi_optional_modules=`$AWK '/^#BEGIN_ASM_LIST/,/^#END_ASM_LIST/ {
 echo '/* created by config.links - do not edit */' >./mpi/asm-syntax.h
 echo "/* Host: ${host} */" >>./mpi/asm-syntax.h
 
-if test "$try_asm_modules" = "yes" ; then
 case "${host}" in
     powerpc-apple-darwin*          | \
     i[34567]86*-*-openbsd[12]*     | \
@@ -142,10 +145,10 @@ case "${host}" in
 	mpi_cpu_arch="aarch64"
 	;;
     arm*-*-*)
+	mpi_cpu_arch="arm"
 	if test "$gcry_cv_gcc_arm_platform_as_ok" = "yes" ; then
 	  echo '/* configured for arm */' >>./mpi/asm-syntax.h
 	  path="arm"
-	  mpi_cpu_arch="arm"
 	else
 	  echo '/* No assembler modules configured */' >>./mpi/asm-syntax.h
 	  path=""
@@ -155,16 +158,19 @@ case "${host}" in
 	echo '/* configured for HPPA (pa7000) */' >>./mpi/asm-syntax.h
 	path="hppa1.1 hppa"
 	mpi_extra_modules="udiv-qrnnd"
+	mpi_cpu_arch="hppa"
 	;;
     hppa1.0*-*-*)
 	echo '/* configured for HPPA 1.0 */' >>./mpi/asm-syntax.h
 	path="hppa"
 	mpi_extra_modules="udiv-qrnnd"
+	mpi_cpu_arch="hppa"
 	;;
     hppa*-*-*)	# assume pa7100
 	echo '/* configured for HPPA (pa7100) */' >>./mpi/asm-syntax.h
 	path="pa7100 hppa1.1 hppa"
 	mpi_extra_modules="udiv-qrnnd"
+	mpi_cpu_arch="hppa"
 	;;
     sparc64-*-linux-gnu)
         echo '/* No working assembler modules available */' >>./mpi/asm-syntax.h
@@ -300,6 +306,7 @@ case "${host}" in
 	mpi_sflags="-Wa,-mpwr"
 	path="power"
 	mpi_extra_modules="udiv-w-sdiv"
+	mpi_cpu_arch="ppc"
 	;;
     rs6000-*-* | \
     power-*-*  | \
@@ -333,13 +340,23 @@ case "${host}" in
         mpi_cpu_arch="ppc"
 	;;
     *)
-	echo '/* No assembler modules configured */' >>./mpi/asm-syntax.h
+	echo '/* Platform not known */' >>./mpi/asm-syntax.h
 	path=""
 	;;
 esac
-else
-    echo '/* Assembler modules disabled on request */' >>./mpi/asm-syntax.h
+
+# If asm modules are disabled reset the found variables but keep
+# mpi_cpu_arch.
+if test "$try_asm_modules" != "yes" ; then
+    echo '/* Assembler modules disabled on request */' >./mpi/asm-syntax.h
     path=""
+    mpi_sflags=""
+    mpi_extra_modules=""
+fi
+
+# Make sure that mpi_cpu_arch is not the empty string.
+if test x"$mpi_cpu_arch" = x ; then
+    mpi_cpu_arch="unknown"
 fi