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Simplify implementation of DAA.

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This commit is contained in:
Thomas Harte 2023-11-08 22:06:58 -05:00
parent da7582d4b5
commit 502b9d2023
1 changed files with 1 additions and 8 deletions
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9
InstructionSets/x86/Implementation/BCD.hpp
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@ -162,22 +162,15 @@ void daa(
The SF, ZF, and PF flags are set according to the result. The OF flag is undefined.
*/
const uint8_t old_al = al;
const auto old_carry = context.flags.template flag<Flag::Carry>();
context.flags.template set_from<Flag::Carry>(0);
if((al & 0x0f) > 0x09 || context.flags.template flag<Flag::AuxiliaryCarry>()) {
context.flags.template set_from<Flag::Carry>(old_carry | (al > 0xf9));
al += 0x06;
context.flags.template set_from<Flag::AuxiliaryCarry>(1);
} else {
context.flags.template set_from<Flag::AuxiliaryCarry>(0);
}
if(old_al > 0x99 || old_carry) {
if(old_al > 0x99 || context.flags.template flag<Flag::Carry>()) {
al += 0x60;
context.flags.template set_from<Flag::Carry>(1);
} else {
context.flags.template set_from<Flag::Carry>(0);
}
context.flags.template set_from<uint8_t, Flag::Zero, Flag::Sign, Flag::ParityOdd>(al);