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BISB/BICB: keep MSB for register operations

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folkert van heusden 2024-05-02 01:32:21 +02:00
parent 6974234d5e
commit 0a0807e1ad
Signed by untrusted user who does not match committer: folkert
GPG key ID: 6B6455EDFEED3BD1
1 changed files with 45 additions and 20 deletions
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65
cpu.cpp
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@ -641,39 +641,64 @@ bool cpu::double_operand_instructions(const uint16_t instr)
} }
case 0b100: { // BIC/BICB Bit Clear Word/Byte case 0b100: { // BIC/BICB Bit Clear Word/Byte
gam_rc_t g_src = getGAM(src_mode, src_reg, word_mode, rm_cur); gam_rc_t g_src = getGAM(src_mode, src_reg, word_mode, rm_cur);
auto g_dst = getGAM(dst_mode, dst_reg, word_mode, rm_cur); if (dst_mode == 0) {
addToMMR1(g_src); // keep here because of order of updates
addToMMR1(g_dst); uint16_t v = getRegister(dst_reg); // need the full word
addToMMR1(g_src); uint16_t result = v & ~g_src.value.value();
uint16_t result = g_dst.value.value() & ~g_src.value.value(); setRegister(dst_reg, result);
if (put_result(g_dst, result)) setPSW_flags_nzv(result, word_mode);
setPSW_flags_nzv(result, word_mode); }
else {
auto g_dst = getGAM(dst_mode, dst_reg, word_mode, rm_cur);
return true; addToMMR1(g_dst);
addToMMR1(g_src);
uint16_t result = g_dst.value.value() & ~g_src.value.value();
if (put_result(g_dst, result))
setPSW_flags_nzv(result, word_mode);
}
return true;
} }
case 0b101: { // BIS/BISB Bit Set Word/Byte case 0b101: { // BIS/BISB Bit Set Word/Byte
// TODO: retain MSB for register operations? gam_rc_t g_src = getGAM(src_mode, src_reg, word_mode, rm_cur);
gam_rc_t g_src = getGAM(src_mode, src_reg, word_mode, rm_cur);
auto g_dst = getGAM(dst_mode, dst_reg, word_mode, rm_cur); if (dst_mode == 0) {
addToMMR1(g_src); // keep here because of order of updates
addToMMR1(g_dst); uint16_t v = getRegister(dst_reg); // need the full word
addToMMR1(g_src); uint16_t result = v | g_src.value.value();
uint16_t result = g_dst.value.value() | g_src.value.value(); setRegister(dst_reg, result);
if (put_result(g_dst, result)) { setPSW_n(SIGN(result, word_mode));
setPSW_n(SIGN(result, word_mode)); setPSW_z(IS_0(result, word_mode));
setPSW_z(IS_0(result, word_mode)); setPSW_v(false);
setPSW_v(false); }
} else {
auto g_dst = getGAM(dst_mode, dst_reg, word_mode, rm_cur);
return true; addToMMR1(g_dst);
addToMMR1(g_src);
uint16_t result = g_dst.value.value() | g_src.value.value();
if (put_result(g_dst, result)) {
setPSW_n(SIGN(result, word_mode));
setPSW_z(IS_0(result, word_mode));
setPSW_v(false);
}
}
return true;
} }
case 0b110: { // ADD/SUB Add/Subtract Word case 0b110: { // ADD/SUB Add/Subtract Word