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Switched to a better ABCD fix.

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This commit is contained in:
Thomas Harte 2019-03-17 22:04:32 -04:00
parent 0d7bbdad54
commit 1d801acf72
1 changed files with 4 additions and 4 deletions
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8
Processors/68000/Implementation/68000Implementation.hpp
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@ -91,9 +91,9 @@ template <class T, bool dtack_is_implicit> void Processor<T, dtack_is_implicit>:
// Perform the BCD add by evaluating the two nibbles separately.
int result = (destination & 0xf) + (source & 0xf) + (extend_flag_ ? 1 : 0);
if(result > 0x9) result += 0x06;
if(result > 0x09) result += 0x06;
result += (destination & 0xf0) + (source & 0xf0);
if((result&0xff0) > 0x90) result += 0x60;
if(result > 0x99) result += 0x60;
// Set all flags essentially as if this were normal addition.
zero_flag_ |= result & 0xff;
@ -112,9 +112,9 @@ template <class T, bool dtack_is_implicit> void Processor<T, dtack_is_implicit>:
// Perform the BCD add by evaluating the two nibbles separately.
int result = (destination & 0xf) - (source & 0xf) - (extend_flag_ ? 1 : 0);
if(result > 0x9) result -= 0x06;
if(result > 0x09) result -= 0x06;
result += (destination & 0xf0) - (source & 0xf0);
if((result&0xff0) > 0x90) result -= 0x60;
if(result > 0x99) result -= 0x60;
// Set all flags essentially as if this were normal subtraction.
zero_flag_ |= result & 0xff;