Better detection and implementation for cpuid instruction on Intel-derived processors, both 32-bit and 64-bit

4 files changed, 31 insertions, 18 deletions

diff --git a/ChangeLog b/ChangeLog
index 58750bd..22793e9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2012-05-02  Jan Nijtmans  <nijtmans@users.sf.net>
+
+	* generic/configure.in:    Better detection and implementation for cpuid
+	* generic/configure:       instruction on Intel-derived processors, both
+	* generic/tclUnixCompat.c: 32-bit and 64-bit.
+
 2012-04-27  Donal K. Fellows  <dkf@users.sf.net>
 
 	* library/init.tcl (auto_execok): Allow shell builtins to be detected
diff --git a/unix/configure b/unix/configure
index 1a0d882..4898cfb 100755
--- a/unix/configure
+++ b/unix/configure
@@ -9339,13 +9339,17 @@ else
 
 int main() {
 
-	int index,ax,bx,cx,dx;
-	__asm__ __volatile__ ("cpuid":\
-	"=a" (ax), "=b" (bx), "=c" (cx), "=d" (dx) : "a" (index));
+	int index,regsPtr[4];
+    __asm__ __volatile__("mov %%ebx, %%edi     \n\t"
+                 "cpuid            \n\t"
+                 "mov %%ebx, %%esi   \n\t"
+                 "mov %%edi, %%ebx  \n\t"
+                 : "=a"(regsPtr[0]), "=S"(regsPtr[1]), "=c"(regsPtr[2]), "=d"(regsPtr[3])
+                 : "a"(index));
     
 ; return 0; }
 EOF
-if { (eval echo configure:9349: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:9353: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   tcl_cv_cpuid=yes
 else
@@ -9394,7 +9398,7 @@ if test "`uname -s`" = "Darwin" ; then
     
     if test "`uname -s`" = "Darwin" ; then
 	echo $ac_n "checking how to package libraries""... $ac_c" 1>&6
-echo "configure:9398: checking how to package libraries" >&5
+echo "configure:9402: checking how to package libraries" >&5
 	# Check whether --enable-framework or --disable-framework was given.
 if test "${enable_framework+set}" = set; then
   enableval="$enable_framework"
diff --git a/unix/configure.in b/unix/configure.in
index c04c735..869fbaa 100644
--- a/unix/configure.in
+++ b/unix/configure.in
@@ -571,12 +571,16 @@ AC_MSG_RESULT([$tcl_ok])
 
 AC_CACHE_CHECK([whether the cpuid instruction is usable], tcl_cv_cpuid, [
     AC_TRY_LINK(, [
-	int index,ax,bx,cx,dx;
-	__asm__ __volatile__ ("cpuid":\
-	"=a" (ax), "=b" (bx), "=c" (cx), "=d" (dx) : "a" (index));
+	int index,regsPtr[4];
+    __asm__ __volatile__("mov %%ebx, %%edi     \n\t"
+                 "cpuid            \n\t"
+                 "mov %%ebx, %%esi   \n\t"
+                 "mov %%edi, %%ebx  \n\t"
+                 : "=a"(regsPtr[0]), "=S"(regsPtr[1]), "=c"(regsPtr[2]), "=d"(regsPtr[3])
+                 : "a"(index));
     ], tcl_cv_cpuid=yes, tcl_cv_cpuid=no)])
 if test $tcl_cv_cpuid = yes; then
-    AC_DEFINE(HAVE_CPUID)
+    AC_DEFINE(HAVE_CPUID, 1, [Is the cpuid instruction usable?])
 fi
 
 #--------------------------------------------------------------------
diff --git a/unix/tclUnixCompat.c b/unix/tclUnixCompat.c
index 1043115..6e2666b 100644
--- a/unix/tclUnixCompat.c
+++ b/unix/tclUnixCompat.c
@@ -675,8 +675,7 @@ TclpGetHostByAddr(const char *addr, int length, int type)
  *	Get CPU ID information on an Intel box under UNIX (either Linux or Cygwin)
  *
  * Results:
- *	Returns TCL_OK if successful, TCL_ERROR if CPUID is not supported or
- *	fails.
+ *	Returns TCL_OK if successful, TCL_ERROR if CPUID is not supported.
  *
  * Side effects:
  *	If successful, stores EAX, EBX, ECX and EDX registers after the CPUID
@@ -692,14 +691,14 @@ TclWinCPUID(
 {
     int status = TCL_ERROR;
 
-#if defined(HAVE_CPUID) && defined(__CYGWIN__)
-    __asm__ __volatile__("pushl %%ebx      \n\t" /* save %ebx */
+    /* See: <http://en.wikipedia.org/wiki/CPUID> */
+#if defined(HAVE_CPUID)
+    __asm__ __volatile__("mov %%ebx, %%edi     \n\t" /* save %ebx */
                  "cpuid            \n\t"
-                 "movl %%ebx, %1   \n\t" /* save what cpuid just put in %ebx */
-                 "popl %%ebx       \n\t" /* restore the old %ebx */
-                 : "=a"(regsPtr[0]), "=r"(regsPtr[1]), "=c"(regsPtr[2]), "=d"(regsPtr[3])
-                 : "a"(index)
-                 : "cc");
+                 "mov %%ebx, %%esi   \n\t" /* save what cpuid just put in %ebx */
+                 "mov %%edi, %%ebx  \n\t" /* restore the old %ebx */
+                 : "=a"(regsPtr[0]), "=S"(regsPtr[1]), "=c"(regsPtr[2]), "=d"(regsPtr[3])
+                 : "a"(index));
     status = TCL_OK;
 #endif
     return status;