ShuriZma
/
stella
mirror of https://github.com/stella-emu/stella.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Optimized Cart::isProbablySC. Perhaps a small change, but more 

efficiency never hurts.
This commit is contained in:
Stephen Anthony 2017-03-16 20:41:37 -02:30
parent 02a399a8aa
commit 0e712b39e1
2 changed files with 8 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
src/emucore/Cart.cxx
View File

@ -314,7 +314,7 @@ bool Cartridge::saveROM(ofstream& out)
int size = -1; int size = -1;
const uInt8* image = getImage(size); const uInt8* image = getImage(size);
if(image == 0 || size <= 0) if(image == nullptr || size <= 0)
{ {
cerr << "save not supported" << endl; cerr << "save not supported" << endl;
return false; return false;
@ -576,14 +576,13 @@ bool Cartridge::isProbablySC(const uInt8* image, uInt32 size)
{ {
// We assume a Superchip cart repeats the first 128 bytes for the second // We assume a Superchip cart repeats the first 128 bytes for the second
// 128 bytes in the RAM area, which is the first 256 bytes of each 4K bank // 128 bytes in the RAM area, which is the first 256 bytes of each 4K bank
uInt32 banks = size / 4096; while(size)
for(uInt32 i = 0; i < banks; ++i)
{ {
for(uInt32 j = 0; j < 128; ++j) if(memcmp(image, image + 128, 128) != 0)
{ return false;
if(image[i*4096+j] != image[i*4096+j + 128])
return false; image += 4096;
} size -= 4096;
} }
return true; return true;
} }

1
src/emucore/Cart.hxx
View File

@ -259,6 +259,7 @@ class Cartridge : public Device
/** /**
Returns true if the image is probably a SuperChip (256 bytes RAM) Returns true if the image is probably a SuperChip (256 bytes RAM)
Note: should be called only on ROMs with size multiple of 4K
*/ */
static bool isProbablySC(const uInt8* image, uInt32 size); static bool isProbablySC(const uInt8* image, uInt32 size);