X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Usermode%2FLibraries%2Flibgcc.so_src%2Flibgcc.c;h=bd5d1f3a3c65c502457341a092d9c5719fbd85cd;hb=da7ef0c8cace452ccfdfa0881a3c0b09970874d8;hp=3b0f212480019258c469a1508d2db969470e9bbb;hpb=b7beadbbf953f23b9d88db5ede3720003fac69d4;p=tpg%2Facess2.git

diff --git a/Usermode/Libraries/libgcc.so_src/libgcc.c b/Usermode/Libraries/libgcc.so_src/libgcc.c
index 3b0f2124..bd5d1f3a 100644
--- a/Usermode/Libraries/libgcc.so_src/libgcc.c
+++ b/Usermode/Libraries/libgcc.so_src/libgcc.c
@@ -25,14 +25,66 @@ void __stack_chk_fail()
  */
 uint64_t __udivdi3(uint64_t Num, uint64_t Den)
 {
+	#if 0
 	uint64_t	ret = 0;
 	if(Den == 0)	// Call Div by Zero Error
 		__asm__ __volatile__ ("int $0");
+	
+	if(Den == 1)	return Num;
+	if(Den == 2)	return Num >> 1;
+	if(Den == 4)	return Num >> 2;
+	if(Den == 8)	return Num >> 3;
+	if(Den == 16)	return Num >> 4;
+	if(Den == 32)	return Num >> 5;
+	if(Den == 64)	return Num >> 6;
+	if(Den == 128)	return Num >> 7;
+	if(Den == 256)	return Num >> 8;
+	
 	while(Num > Den) {
 		ret ++;
 		Num -= Den;
 	}
 	return ret;
+	#else
+	uint64_t	P[2];
+	uint64_t	q;
+	 int	i;
+	
+	if(Den == 0)	__asm__ __volatile__ ("int $0x0");
+	// Common speedups
+	if(Num <= 0xFFFFFFFF && Den <= 0xFFFFFFFF)
+		return Num / Den;
+	if(Den == 1)	return Num;
+	if(Den == 2)	return Num >> 1;
+	if(Den == 16)	return Num >> 4;
+	if(Num < Den)	return 0;
+	if(Num < Den*2)	return 1;
+	if(Num == Den*2)	return 2;
+	
+	// Restoring division, from wikipedia
+	// http://en.wikipedia.org/wiki/Division_(digital)
+	P[0] = Num;	P[1] = 0;
+	for( i = 64; i--; )
+	{
+		// P <<= 1;
+		P[1] = (P[1] << 1) | (P[0] >> 63);
+		P[0] = P[0] << 1;
+		
+		// P -= Den << 64
+		P[1] -= Den;
+		
+		// P >= 0
+		if( !(P[1] & (1ULL<<63)) ) {
+			q |= (uint64_t)1 << (63-i);
+		}
+		else {
+			//q |= 0 << (63-i);
+			P[1] += Den;
+		}
+	}
+	
+	return q;
+	#endif
 }
 
 /**
@@ -41,9 +93,36 @@ uint64_t __udivdi3(uint64_t Num, uint64_t Den)
  */
 uint64_t __umoddi3(uint64_t Num, uint64_t Den)
 {
-	if(Den == 0)	// Call Div by Zero Error
-		__asm__ __volatile__ ("int $0");
-	while(Num >= Den)
-		Num -= Den;
+	#if 0
+	if(Den == 0)	__asm__ __volatile__ ("int $0");	// Call Div by Zero Error
+	
+	if(Den == 1)	return 0;
+	if(Den == 2)	return Num & 0x01;
+	if(Den == 4)	return Num & 0x03;
+	if(Den == 8)	return Num & 0x07;
+	if(Den == 16)	return Num & 0x0F;
+	if(Den == 32)	return Num & 0x1F;
+	if(Den == 64)	return Num & 0x3F;
+	if(Den == 128)	return Num & 0x3F;
+	if(Den == 256)	return Num & 0x7F;
+	
+	while(Num >= Den)	Num -= Den;
+	
 	return Num;
+	#else
+	if(Den == 0)	__asm__ __volatile__ ("int $0");	// Call Div by Zero Error
+	
+	// Speedups
+	if(Num < Den)	return Num;
+	if(Num == Den)	return 0;
+	if(Num <= 0xFFFFFFFF && Den <= 0xFFFFFFFF)
+		return Num % Den;
+	
+	// Speedups for common operations
+	if(Den == 1)	return 0;
+	if(Den == 2)	return Num & 0x01;
+	if(Den == 8)	return Num & 0x07;
+	if(Den == 16)	return Num & 0x0F;
+	return Num - __udivdi3(Num, Den) * Den;
+	#endif
 }