configure altivec patch by Magnus Damm <damm@opensource.se>

*  CC is not checked for Altivec support (see above).
   The patch adds checks for FSF-style flags and Darwin-style flags.
   The check is performed regardless of the gcc version.

*  Disabling of Altivec.
   --disable-altivec is broken today if /proc/cpuinfo shows that your cpu
   supports altivec. The patch takes care of that.

*  "GCC & CPU optimization abilities" always show that it is optimizing
   for the cpu configure is running on, it should show the optimization that
   is enabled for gcc instead. Cosmetic change only, but confusing as it is
   today IMHO.

*  Runtime CPU-detection now enables altivec for powerpc.

Now with the patch it should be possible to use --enable-altivec,
--disable-altivec, --enable-runtime-cpudetection regardless of powerpc cpu type.

The configure script handles altivec support in the following order:

1. Altivec is enabled by default if your cpu supports it.
2. --enable-runtime-cpudetection will enable altivec support.
3. If you have forced altivec on/off with --enable-altivec/--disable-altivec, then
   your selection will override the previous altivec configuration.
4. If altivec is enabled but the compiler doesn't support it, altivec gets turned off.


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@11008 b3059339-0415-0410-9bf9-f77b7e298cf2

configure

@@ -833,26 +833,29 @@ EOF
     proc=''
     _march=''
     _mcpu=''
+    _optimizing=''
     _altivec=no
-    _altivec_gcc_flags=''
 
     echocheck "CPU type"
     if linux && test -n "$_cpuinfo"; then
 	proc=`$_cpuinfo | grep 'cpu' | cut -d ':' -f 2 | cut -d ',' -f 1 | cut -b 2- | head -1`
 	if test -n "`$_cpuinfo | grep altivec`"; then
 	    _altivec=yes
-            _altivec_gcc_flags='-maltivec -mabi=altivec'
 	fi
     fi
     if darwin ; then
 	if [ `sysctl -n hw.vectorunit` -eq 1 ]; then
 	    _altivec=yes
-            _altivec_gcc_flags='-faltivec'
  	fi
     fi
-    echores "$proc"
+    if test "$_altivec" = yes; then
+        echores "$proc altivec"
+    else
+        echores "$proc"
+    fi
 
     echocheck "GCC & CPU optimization abilities"
+
     if test -n "$proc"; then
         case "$proc" in
 	    601) _march='-mcpu=601' _mcpu='-mtune=601' ;;
@@ -872,11 +875,14 @@ EOF
     	    esac
 	fi
     fi
-    echores "$proc"
-    
-    _optimizing="$proc"
 
-    _mcpu="$_mcpu $_altivec_gcc_flags"
+    if test -n "$_mcpu"; then
+        _optimizing=`echo $_mcpu | cut -c 8-`
+        echores "$_optimizing"
+    else
+        echores "none"
+    fi
+
     ;;
 
   alpha)
@@ -987,7 +993,9 @@ if test "$_runtime_cpudetection" = yes ; then
     _sse2=yes
     _mtrr=yes
   fi
-  _optimizing="Runtime CPU-Detection enabled"
+  if ppc; then
+    _altivec=yes
+  fi
 fi
 
 if x86 && test "$_runtime_cpudetection" = no ; then
@@ -1604,6 +1612,87 @@ if x86 ; then
   fi
 fi
 
+if ppc ; then
+    
+    # check if altivec is supported by the compiler, and how to enable it
+
+    _altivec_gcc_flags=''
+
+    if test "$_altivec" = yes -o "$_runtime_cpudetection" = yes ; then
+        echocheck "GCC altivec support"
+        
+        p=''
+        cat > $TMPC << EOF
+int main() {
+    return 0;
+}
+EOF
+        FSF_flags='-maltivec -mabi=altivec'
+        Darwin_flags='-faltivec'
+
+        if test -z "$p"; then
+            cc_check $FSF_flags && p='FSF'
+        fi
+        if test -z "$p"; then
+            cc_check $Darwin_flags && p='Darwin'
+        fi
+
+        case $p in
+            FSF) _altivec_gcc_flags="$FSF_flags" _altivec=yes ;;
+            Darwin) _altivec_gcc_flags="$Darwin_flags" _altivec=yes ;;
+            *) _altivec=no ;;
+        esac
+
+        if test -z "$p"; then
+            p=none
+        else
+            p="$p-style ($_altivec_gcc_flags)"
+        fi
+
+        echores "$p"
+    fi
+
+    # check if <altivec.h> should be included
+
+    _def_altivec_h='#undef HAVE_ALTIVEC_H'
+    _def_altivec='#undef HAVE_ALTIVEC'
+
+    if test "$_altivec" = yes ; then
+        echocheck "altivec.h"
+        cat > $TMPC << EOF
+#include <altivec.h>
+int main(void) { return 0; }
+EOF
+        _have_altivec_h=no
+         cc_check $_altivec_gcc_flags && _have_altivec_h=yes
+         if test "$_have_altivec_h" = yes ; then
+             _def_altivec_h='#define HAVE_ALTIVEC_H 1'
+             _def_altivec='#define HAVE_ALTIVEC 1'
+         fi
+         echores "$_have_altivec_h"
+    fi
+
+    # disable runtime cpudetection if 
+    # - we cannot generate altivec code
+    # - altivec is disabled by the user
+
+    if test "$_runtime_cpudetection" = yes -a "$_altivec" = no ; then
+        _runtime_cpudetection=no
+    fi
+
+    # show that we are optimizing for altivec (if enabled and supported)
+
+    if test "$_runtime_cpudetection" = no -a "$_altivec" = yes ; then
+	_optimizing="$_optimizing altivec"
+    fi
+
+    # if altivec is enabled, make sure the correct flags turn up in CFLAGS
+
+    if test "$_altivec" = yes ; then
+        _mcpu="$_mcpu $_altivec_gcc_flags"
+    fi
+fi
+
 _def_mmx='#undef HAVE_MMX'
 test "$_mmx" = yes && _def_mmx='#define HAVE_MMX 1'
 _def_mmx2='#undef HAVE_MMX2'
@@ -1616,9 +1705,6 @@ _def_sse='#undef HAVE_SSE'
 test "$_sse" = yes && _def_sse='#define HAVE_SSE 1'
 _def_sse2='#undef HAVE_SSE2'
 test "$_sse2" = yes && _def_sse2='#define HAVE_SSE2 1'
-_def_altivec='#undef HAVE_ALTIVEC'
-test "$_altivec" = yes && _def_altivec='#define HAVE_ALTIVEC 1'
-
 
 # Checking kernel version...
 if x86 && linux ; then
@@ -1796,6 +1882,7 @@ echores "$_sighandler"
 
 echocheck "runtime cpudetection"
 if test "$_runtime_cpudetection" = yes ; then
+  _optimizing="Runtime CPU-Detection enabled"
   _def_runtime_cpudetection='#define RUNTIME_CPUDETECT 1'
 else
   _def_runtime_cpudetection='#undef RUNTIME_CPUDETECT'
@@ -2068,24 +2155,6 @@ else
 fi
 echores "$_mman"
 
-if ppc && test "$_altivec" = "yes" ; then
-echocheck "altivec.h"
-cat > $TMPC << EOF
-#include <altivec.h>
-int main(void) { return 0; }
-EOF
-_have_altivec_h=no
-cc_check $_altivec_gcc_flags && _have_altivec_h=yes
-if test "$_have_altivec_h" = yes ; then
-  _def_altivec_h='#define HAVE_ALTIVEC_H 1'
-else
-  _def_altivec_h='#undef HAVE_ALTIVEC_H'
-fi
-echores "$_have_altivec_h"
-else
-  _def_altivec_h='#undef HAVE_ALTIVEC_H'
-fi
-
 echocheck "dynamic loader"
 cat > $TMPC << EOF
 #include <dlfcn.h>