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flag fixes

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folkert van heusden 2022-03-31 23:18:11 +02:00
parent afd84445eb
commit c53ecb2be6
1 changed files with 18 additions and 18 deletions
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36
cpu.cpp
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@ -355,15 +355,15 @@ bool cpu::double_operand_instructions(const uint16_t instr)
if (operation == 0b111)
return additional_double_operand_instructions(instr);
const uint8_t src = (instr >> 6) & 63;
const uint8_t src_mode = (src >> 3) & 7;
const uint8_t src_reg = src & 7;
const uint8_t src = (instr >> 6) & 63;
const uint8_t src_mode = (src >> 3) & 7;
const uint8_t src_reg = src & 7;
uint16_t src_value = operation == 0b110 ? 0 : getGAM(src_mode, src_reg, word_mode, false);
const uint16_t src_value = operation == 0b110 ? 0 : getGAM(src_mode, src_reg, word_mode, false);
const uint8_t dst = instr & 63;
const uint8_t dst_mode = (dst >> 3) & 7;
const uint8_t dst_reg = dst & 7;
const uint8_t dst = instr & 63;
const uint8_t dst_mode = (dst >> 3) & 7;
const uint8_t dst_reg = dst & 7;
switch(operation) {
case 0b001: { // MOV/MOVB Move Word/Byte
@ -432,21 +432,21 @@ bool cpu::double_operand_instructions(const uint16_t instr)
}
case 0b110: { // ADD/SUB Add/Subtract Word
src_value = getGAM(src_mode, src_reg, false, false);
int16_t ssrc_value = getGAM(src_mode, src_reg, false, false);
uint16_t dst_addr = getGAMAddress(dst_mode, dst_reg, false, false);
int16_t dst_value = b->readWord(dst_addr);
int16_t result = 0;
uint16_t dst_addr = getGAMAddress(dst_mode, dst_reg, false, false);
int16_t dst_value = b->readWord(dst_addr);
int16_t result = 0;
if (instr & 0x8000) {
result = (dst_value - src_value) & 0xffff;
setPSW_v(sign(src_value) != sign(dst_value) && sign(src_value) == sign(result));
setPSW_c(uint16_t(dst_value) < uint16_t(src_value));
result = (dst_value - ssrc_value) & 0xffff;
setPSW_v(sign(ssrc_value) != sign(dst_value) && sign(ssrc_value) == sign(result));
setPSW_c(uint16_t(dst_value) < uint16_t(ssrc_value));
}
else {
result = (dst_value + src_value) & 0xffff;
setPSW_v(sign(src_value) == sign(dst_value) && sign(dst_value) != sign(result));
setPSW_c(uint16_t(result) < uint16_t(src_value));
result = (dst_value + ssrc_value) & 0xffff;
setPSW_v(sign(ssrc_value) == sign(dst_value) && sign(dst_value) != sign(result));
setPSW_c(uint16_t(result) < uint16_t(ssrc_value));
}
setPSW_n(result < 0);
@ -556,7 +556,7 @@ bool cpu::additional_double_operand_instructions(const uint16_t instr)
setPSW_n(R < 0);
setPSW_z(R == 0);
setPSW_v(sign(R) != sign(oldR));
setPSW_v(SIGN(R, false) != SIGN(oldR, false));
setRegister(reg, R);