[AD] Pentium Pro optimizations under *nix

[Evert Glebbeek <eglebbk@xxxxxxxxxx>]

In Windows and DOS, it is possible to optimize for pentium pro by setting 
TARGET_ARCH_COMPAT=i686. It is also possible to generate code specific for 
a certain processor by specifying TARGET_ARCH_EXCL.
The Unix port only has the --enable-pentiumopts switch to configure, which 
amounds to TARGET_ARCH_COMPAT=i585.

The attached patch adds a --enable-i686opts to the configure script 
(default value: no) and a --enable-exclopts flag (default value again no) 
that can be used to generate specific code for either the pentium, or the 
pentium pro. If both --enable-pentiumopts and ---enable-i686opts are 
specified, it goes with the lowest system, that is, the pentium.

Tested under Linux (on an i686) with 4.0.2 and WIP 4.1.3

On a side note, should these confugure options be documented anywhere?

--- configure.in.old	Tue Oct  1 20:22:45 2002
+++ configure.in	Tue Oct  1 20:37:16 2002
@@ -77,6 +77,16 @@
 [  --enable-pentiumopts[=x] enable Pentium optimizations [default=no]],
 test "X$enableval" != "Xno" && allegro_pentium_optimizations=yes)
 
+dnl Enable Pentium Pro optimizations.
+AC_ARG_ENABLE(i686opts,
+[  --enable-i686opts[=x]   enable Pentium Pro optimizations [default=no]],
+test "X$enableval" != "Xno" && allegro_pentiumpro_optimizations=yes)
+
+dnl Enable exclusive code generation.
+AC_ARG_ENABLE(exclopts,
+[  --enable-exclopts[=x]   enable processor exclusive optimizations [default=no]],
+test "X$enableval" != "Xno" && allegro_exclusive_optimizations=yes)
+
 dnl Sanity check on shared/static options
 if test "X$allegro_static_libraries" != "Xyes"; then
   if test "X$allegro_shared_libraries" != "Xyes"; then
@@ -167,11 +177,22 @@
   else
     WFLAGS="-Wall"
   fi
-  if test "X$allegro_pentium_optimizations" = "Xyes"; then
-    TARGET_ARCH="-mcpu=pentium"
+  if test "X$allegro_pentiumpro_optimizations" = "Xyes"; then
+    if test "X$allegro_exclusive_optimizations" = "Xyes"; then
+       TARGET_ARCH="-march=i686"
+    else
+       TARGET_ARCH="-mcpu=i686"
+    fi   
   else
     TARGET_ARCH=
   fi
+  if test "X$allegro_pentium_optimizations" = "Xyes"; then
+    if test "X$allegro_exclusive_optimizations" = "Xyes"; then
+       TARGET_ARCH="-march=pentium"
+    else
+       TARGET_ARCH="-mcpu=pentium"
+    fi   
+  fi
   if test "X$allegro_cv_support_fomit_frame_pointer" = "Xyes"; then
     CFLAGS="$TARGET_ARCH -O2 -funroll-loops -ffast-math -fomit-frame-pointer $WFLAGS"
   else