Remove redundant CLC

This commit is contained in:
offtkp 2024-09-02 02:14:54 +03:00
parent 1e9ca6fb7f
commit ba545cf83f

View file

@ -308,21 +308,21 @@ static void GenerateBLSI(const ZydisDecodedOperand* operands, Xbyak::CodeGenerat
SaveRegisters(c, {scratch});
// BLSI sets CF to zero if source is zero, otherwise it sets CF to one.
Xbyak::Label carrySet, carryNotSet, end;
Xbyak::Label set_carry, clear_carry, end;
c.mov(scratch, *src);
c.neg(scratch); // NEG, like BLSI, clears CF if the source is zero and sets it otherwise
c.jc(carrySet);
c.jmp(carryNotSet);
c.jc(set_carry);
c.jmp(clear_carry);
c.L(carrySet);
c.L(set_carry);
c.and_(scratch, *src);
c.stc(); // setting/clearing carry needs to happen after the AND because that clears CF
c.jmp(end);
c.L(carryNotSet);
c.L(clear_carry);
c.and_(scratch, *src);
c.clc();
// We don't need to clear carry here since AND does that for us
c.L(end);
c.mov(dst, scratch);