[Opencore-amr-commits] [fdk-aac] Do schur_div with a direct 64 bit division ...

[Martin Storsjö <mst...@us...>]

    Module: fdk-aac
    Branch: master
    Commit: 923f3e95f3e332d26f03cf6782f0ab61596ceef2
    Author: Jakub Stachowski <qb...@go...>
 Committer: Martin Storsjo <ma...@ma...>
      Date: Tue Aug 14 21:59:32 2012 +0200
       URL: http://opencore-amr.git.sf.net/git/gitweb.cgi?p=opencore-amr/fdk-aac;a=commit;h=923f3e95f3e332d26f03cf6782f0ab61596ceef2

Do schur_div with a direct 64 bit division instead of a loop on x86

This speeds up HE-AACv2 encoding from 3.85 s to 3.42 s on a Core i7.

---

 libFDK/src/fixpoint_math.cpp |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/libFDK/src/fixpoint_math.cpp b/libFDK/src/fixpoint_math.cpp
index 000820c..7d5fbb5 100644
--- a/libFDK/src/fixpoint_math.cpp
+++ b/libFDK/src/fixpoint_math.cpp
@@ -443,6 +443,15 @@ FIXP_DBL sqrtFixp(FIXP_DBL op)
 
 *****************************************************************************/
 
+#if defined(__x86__)
+FIXP_DBL schur_div(FIXP_DBL num, FIXP_DBL denum, INT count)
+{
+    INT64 tmp=(INT64)num<<31;
+    LONG div=(tmp/denum)>>(DFRACT_BITS-count);
+    return (FIXP_DBL)(div) << (DFRACT_BITS-count);
+}
+
+#else
 
 FIXP_DBL schur_div(FIXP_DBL num, FIXP_DBL denum, INT count)
 {
@@ -469,6 +478,7 @@ FIXP_DBL schur_div(FIXP_DBL num, FIXP_DBL denum, INT count)
     return (FIXP_DBL)(div << (DFRACT_BITS - count));
 }
 
+#endif
 
 #endif /* !defined(FUNCTION_schur_div) */