[MPlayer-dev-eng] [PATCH] fast_cmov should be set on x86_64

Reimar Döffinger Reimar.Doeffinger at stud.uni-karlsruhe.de
Tue Dec 23 10:20:35 CET 2008


Hello,
going by what I read by Intel, cmov should be used on everything but the
P4s - since the 64 bit case currently does not explicitly detect them,
only very few with 64 bit support exist, and their performance is horrible
for multimedia anyway I suggest changing the default:

Index: configure
===================================================================
--- configure   (revision 28181)
+++ configure   (working copy)
@@ -1935,6 +1938,7 @@
     else
        cpuopt=-mcpu
     fi
+    test $_fast_cmov = "auto" && _fast_cmov=yes
     if test "$_runtime_cpudetection" = no ; then
       case "$pvendor" in
       AuthenticAMD)
@@ -1946,7 +1950,6 @@
           # 64-bit prescotts exist, but as far as GCC is concerned they
           # have the same capabilities as a nocona.
           proc=nocona
-          test $_fast_cmov = "auto" && _fast_cmov=no
           ;;
         esac
         ;;



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