From fdb3a3415688efdc1e03b43c7ed6f6bcb95da3e5 Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Sun, 23 Apr 2006 10:28:54 +0000
Subject: avoid AVInteger usage in av_rescale disable integer.* (unused)
 libavutil.a 45k -> 32k

Originally committed as revision 5311 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavutil/mathematics.c | 60 ++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 54 insertions(+), 6 deletions(-)

(limited to 'libavutil/mathematics.c')

diff --git a/libavutil/mathematics.c b/libavutil/mathematics.c
index 3cd47a8ac0..54698b7ab1 100644
--- a/libavutil/mathematics.c
+++ b/libavutil/mathematics.c
@@ -22,7 +22,6 @@
  */
 
 #include "common.h"
-#include "integer.h"
 #include "mathematics.h"
 
 const uint8_t ff_sqrt_tab[128]={
@@ -49,7 +48,6 @@ int64_t ff_gcd(int64_t a, int64_t b){
 }
 
 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
-    AVInteger ai;
     int64_t r=0;
     assert(c > 0);
     assert(b >=0);
@@ -65,12 +63,40 @@ int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
             return (a * b + r)/c;
         else
             return a/c*b + (a%c*b + r)/c;
-    }
+    }else{
+#if 1
+        uint64_t a0= a&0xFFFFFFFF;
+        uint64_t a1= a>>32;
+        uint64_t b0= b&0xFFFFFFFF;
+        uint64_t b1= b>>32;
+        uint64_t t1= a0*b1 + a1*b0;
+        uint64_t t1a= t1<<32;
+        int i;
+
+        a0 = a0*b0 + t1a;
+        a1 = a1*b1 + (t1>>32) + (a0<t1a);
+        a0 += r;
+        a1 += a0<r;
 
-    ai= av_mul_i(av_int2i(a), av_int2i(b));
-    ai= av_add_i(ai, av_int2i(r));
+        for(i=63; i>=0; i--){
+//            int o= a1 & 0x8000000000000000ULL;
+            a1+= a1 + ((a0>>i)&1);
+            t1+=t1;
+            if(/*o || */c >= a1){
+                a1 -= c;
+                t1++;
+            }
+        }
+        return t1;
+    }
+#else
+        AVInteger ai;
+        ai= av_mul_i(av_int2i(a), av_int2i(b));
+        ai= av_add_i(ai, av_int2i(r));
 
-    return av_i2int(av_div_i(ai, av_int2i(c)));
+        return av_i2int(av_div_i(ai, av_int2i(c)));
+    }
+#endif
 }
 
 int64_t av_rescale(int64_t a, int64_t b, int64_t c){
@@ -82,3 +108,25 @@ int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
     int64_t c= cq.num * (int64_t)bq.den;
     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
 }
+#if 0
+main(){
+    int64_t a,b,c,d,e;
+
+    for(a=7; a<256*256*256*128LL; a=(a*3)+1){
+        for(b=3; b<256*256*256*128LL; b=(b*5)/4+1){
+            for(c=9; c<256*256*256*128LL; c=(c*7)/5+3 ){
+                int64_t r= c/2;
+                AVInteger ai;
+                ai= av_mul_i(av_int2i(a), av_int2i(b));
+                ai= av_add_i(ai, av_int2i(r));
+
+                d= av_i2int(av_div_i(ai, av_int2i(c)));
+
+                e= av_rescale(a,b,c);
+
+                if(d!=e) printf("%Ld*%Ld/%Ld= %Ld=%Ld\n"L, a, b, c, d, e);
+            }
+        }
+    }
+}
+#endif
\ No newline at end of file
-- 
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