Kernel/arm7 - Fiddling on process switching

[tpg/acess2.git] / Kernel / arch / arm7 / lib.c

diff --git a/Kernel/arch/arm7/lib.c b/Kernel/arch/arm7/lib.c
index e8eb7d3..94c1a3a 100644 (file)
--- a/Kernel/arch/arm7/lib.c
+++ b/Kernel/arch/arm7/lib.c
@@ -6,6 +6,7 @@
 #include <acess.h>
 
 // === PROTOTYPES ===
+Uint64 __divmod64(Uint64 Num, Uint64 Den, Uint64 *Rem);
 Uint64 __udivdi3(Uint64 Num, Uint64 Den);
 Uint64 __umoddi3(Uint64 Num, Uint64 Den);
 Uint32 __udivsi3(Uint32 Num, Uint32 Den);
@@ -112,6 +113,36 @@ void *memset(void *_dest, int _value, size_t _length)
        return _dest;
 }
 
+Uint64 __divmod64(Uint64 Num, Uint64 Den, Uint64 *Rem)
+{
+       Uint64  ret, add;
+
+       ret = 0;
+       add = 1;
+
+       // Find what power of two times Den is > Num
+       while( Num >= Den )
+       {
+               Den <<= 1;
+               add <<= 1;
+       }
+
+       // Search backwards
+       while( add > 1 )
+       {
+               add >>= 1;
+               Den >>= 1;
+               // If the numerator is > Den, subtract and add to return value
+               if( Num > Den )
+               {
+                       ret += add;
+                       Num -= Den;
+               }
+       }
+       if(Rem) *Rem = Num;
+       return ret;
+}
+
 Uint64 DivMod64U(Uint64 Num, Uint64 Den, Uint64 *Rem)
 {
        Uint64  ret;
@@ -132,6 +163,10 @@ Uint64 DivMod64U(Uint64 Num, Uint64 Den, Uint64 *Rem)
                if(Rem) *Rem = Num & 0xF;
                return Num >> 4;
        }
+       if(Den == 32) {
+               if(Rem) *Rem = Num & 0x1F;
+               return Num >> 5;
+       }
        if(Den == 0x1000) {
                if(Rem) *Rem = Num & 0xFFF;
                return Num >> 12;
@@ -156,11 +191,16 @@ Uint64 DivMod64U(Uint64 Num, Uint64 Den, Uint64 *Rem)
                Den >>= 1; tmp >>= 1;
                while(
        }
-       #else
+       if(Rem) *Rem = Num;
+       return ret;
+       #elif 0
        for( ret = 0; Num > Den; ret ++, Num -= Den) ;
-       #endif
        if(Rem) *Rem = Num;
        return ret;
+       #else
+       ret = __divmod64(Num, Den, Rem);
+       return ret;
+       #endif
 }
 
 // Unsigned Divide 64-bit Integer