chris/open-roms
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ignore 3 byte sequences ending in a branch

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This commit is contained in:
Paul Gardner-Stephen committed 2019-04-24 13:44:11 +09:30
1 parent cbd58d62f1
commit d422d45105
1 file changed
+10 -2
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src/similarity.c
+10 -2
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@@ -108,17 +108,25 @@ int main(int argc,char **argv)
if (f1[i]==0xf0) break;
if (f1[i]==0xb0) break;
if (f1[i]==0x10) break;
// Any 2-byte opcode followed by a branch
if (f1[i+2]==0xd0) break;
if (f1[i+2]==0xf0) break;
if (f1[i+2]==0xb0) break;
if (f1[i+2]==0x10) break;
// Common 2-byte instructions followed by
// any single byte are very common and not
// copyrightable.
if (f1[i]==0x85) break;
if (f1[i]==0xa9) break;
if (f1[i]==0x69) break;
if (f1[i]==0xc9) break;
// Similarly for random byte before such instructions
if (f1[i+1]==0x85) break;
if (f1[i+1]==0xa9) break;
if (f1[i+1]==0xc9) break;
if (f1[i+1]==0xa9) break; // LDA #$xx
if (f1[i+1]==0x69) break; // ADC #$xx
if (f1[i+1]==0xc9) break; // CMP #$xx
// Filter out all 3 byte instructions
switch(f1[i]) {