cleanup of cpu::single_operand_instructions
This commit is contained in:
folkert van heusden
parent
daa940986f
commit
1ad1b9aa0a
1 changed files with 210 additions and 187 deletions
397
cpu.cpp
397
cpu.cpp
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@ -564,126 +564,138 @@ bool cpu::additional_double_operand_instructions(const uint16_t instr)
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bool cpu::single_operand_instructions(const uint16_t instr)
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{
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const uint16_t opcode = (instr >> 6) & 0b111111111;
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const uint8_t dst = instr & 63;
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const uint8_t dst_mode = (dst >> 3) & 7;
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const uint8_t dst_reg = dst & 7;
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const bool word_mode = !!(instr & 0x8000);
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uint16_t a = -1;
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int32_t vl = -1;
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uint16_t v = -1;
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const uint16_t opcode = (instr >> 6) & 0b111111111;
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const uint8_t dst = instr & 63;
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const uint8_t dst_mode = (dst >> 3) & 7;
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const uint8_t dst_reg = dst & 7;
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const bool word_mode = !!(instr & 0x8000);
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switch(opcode) {
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case 0b00000011: // SWAB
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if (word_mode) // handled elsewhere
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return false;
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else {
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint8_t t1, t2;
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uint16_t t;
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if (dst_mode == 0) {
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t = getRegister(dst_reg, false);
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t1 = t >> 8;
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t2 = t & 255;
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setRegister(dst_reg, false, (t2 << 8) | t1);
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}
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else {
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t = getRegister(dst_reg, false);
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t1 = b -> readByte(a);
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t2 = b -> readByte(a + 1);
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case 0b00000011: { // SWAB
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if (word_mode) // handled elsewhere
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return false;
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else {
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uint8_t t1 = 0, t2 = 0;
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b -> writeByte(a, t2);
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b -> writeByte(a + 1, t1);
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}
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if (dst_mode == 0) {
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uint16_t t = getRegister(dst_reg, false);
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t1 = t >> 8;
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t2 = t & 255;
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setRegister(dst_reg, false, (t2 << 8) | t1);
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}
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else {
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t t = getRegister(dst_reg, false);
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t1 = b -> readByte(a);
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t2 = b -> readByte(a + 1);
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setPSW_n(t1 & 0x80);
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setPSW_z(t1 == 0);
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setPSW_v(false);
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setPSW_c(false);
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break;
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}
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b -> writeByte(a, t2);
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b -> writeByte(a + 1, t1);
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}
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case 0b000101000: // CLR/CLRB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, 0, false);
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else
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b -> write(a, word_mode, 0);
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setPSW_n(false);
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setPSW_z(true);
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setPSW_v(false);
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setPSW_c(false);
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break;
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setPSW_n(t1 & 0x80);
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setPSW_z(t1 == 0);
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setPSW_v(false);
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setPSW_c(false);
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}
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case 0b000101001: // COM/COMB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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v = b -> read(a, word_mode);
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break;
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}
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if (word_mode)
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v ^= 0xff;
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else
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v ^= 0xffff;
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case 0b000101000: { // CLR/CLRB
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, 0, false);
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else {
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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setPSW_n(SIGN(v, word_mode));
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setPSW_z(v == 0);
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setPSW_v(false);
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setPSW_c(true);
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b -> write(a, word_mode, 0);
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}
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, v, false);
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else
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b -> write(a, word_mode, v);
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setPSW_n(false);
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setPSW_z(true);
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setPSW_v(false);
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setPSW_c(false);
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break;
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break;
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}
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case 0b000101010: // INC/INCB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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v = b -> read(a, word_mode);
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vl = (v + 1) & (word_mode ? 0xff : 0xffff);
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setPSW_n(word_mode ? vl > 127 : vl > 32767);
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setPSW_z(vl == 0);
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setPSW_v(word_mode ? v == 0x7f : v == 0x7fff);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, vl, false);
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else
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b -> write(a, word_mode, vl);
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break;
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case 0b000101001: { // COM/COMB
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t v = b -> read(a, word_mode);
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case 0b000101011: // DEC/DECB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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v = b -> read(a, word_mode);
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vl = (v - 1) & (word_mode ? 0xff : 0xffff);
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setPSW_n(word_mode ? vl > 127 : vl > 32767);
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setPSW_z(vl == 0);
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setPSW_v(word_mode ? v == 0x80 : v == 0x8000);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, vl, false);
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else
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b -> write(a, word_mode, vl);
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break;
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if (word_mode)
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v ^= 0xff;
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else
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v ^= 0xffff;
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case 0b000101100: // NEG/NEGB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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v = b -> read(a, word_mode);
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vl = word_mode ? uint8_t(-int8_t(v)) : -int16_t(v);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, vl, false);
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else
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b -> write(a, word_mode, vl);
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setPSW_n(SIGN(vl, word_mode));
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setPSW_z(vl == 0);
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setPSW_v(word_mode ? vl == 0x80 : vl == 0x8000);
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setPSW_c(vl);
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break;
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setPSW_n(SIGN(v, word_mode));
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setPSW_z(v == 0);
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setPSW_v(false);
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setPSW_c(true);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, v, false);
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else
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b -> write(a, word_mode, v);
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break;
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}
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case 0b000101010: { // INC/INCB
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t v = b -> read(a, word_mode);
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int32_t vl = (v + 1) & (word_mode ? 0xff : 0xffff);
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setPSW_n(word_mode ? vl > 127 : vl > 32767);
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setPSW_z(vl == 0);
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setPSW_v(word_mode ? v == 0x7f : v == 0x7fff);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, vl, false);
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else
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b -> write(a, word_mode, vl);
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break;
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}
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case 0b000101011: { // DEC/DECB
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t v = b -> read(a, word_mode);
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int32_t vl = (v - 1) & (word_mode ? 0xff : 0xffff);
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setPSW_n(word_mode ? vl > 127 : vl > 32767);
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setPSW_z(vl == 0);
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setPSW_v(word_mode ? v == 0x80 : v == 0x8000);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, vl, false);
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else
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b -> write(a, word_mode, vl);
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break;
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}
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case 0b000101100: { // NEG/NEGB
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t v = b -> read(a, word_mode);
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int32_t vl = word_mode ? uint8_t(-int8_t(v)) : -int16_t(v);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, vl, false);
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else
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b -> write(a, word_mode, vl);
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setPSW_n(SIGN(vl, word_mode));
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setPSW_z(vl == 0);
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setPSW_v(word_mode ? vl == 0x80 : vl == 0x8000);
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setPSW_c(vl);
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break;
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}
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case 0b000101101: { // ADC/ADCB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t org = b -> read(a, word_mode);
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t org = b -> read(a, word_mode);
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uint16_t new_ = org + getPSW_c();
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, new_, false);
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else
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b -> write(a, word_mode, new_);
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setPSW_n(SIGN(new_, word_mode));
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setPSW_z(new_ == 0);
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setPSW_v((word_mode ? org == 0x7f : org == 0x7fff) && getPSW_c());
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@ -691,37 +703,41 @@ bool cpu::single_operand_instructions(const uint16_t instr)
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break;
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}
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case 0b000101110: // SBC/SBCB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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//fprintf(stderr, "%d,%d\n", dst_mode, dst_reg);
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v = b -> read(a, word_mode);
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vl = (v - getPSW_c()) & (word_mode ? 0xff : 0xffff);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, vl, false);
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else
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b -> write(a, word_mode, vl);
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setPSW_n(SIGN(vl, word_mode));
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setPSW_z(vl == 0);
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setPSW_v(vl == 0x8000);
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case 0b000101110: { // SBC/SBCB
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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//fprintf(stderr, "%d,%d\n", dst_mode, dst_reg);
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uint16_t v = b -> read(a, word_mode);
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int32_t vl = (v - getPSW_c()) & (word_mode ? 0xff : 0xffff);
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if (v == 0 && getPSW_c())
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setPSW_c(true);
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else
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, vl, false);
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else
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b -> write(a, word_mode, vl);
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setPSW_n(SIGN(vl, word_mode));
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setPSW_z(vl == 0);
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setPSW_v(vl == 0x8000);
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if (v == 0 && getPSW_c())
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setPSW_c(true);
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else
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setPSW_c(false);
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break;
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}
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case 0b000101111: { // TST/TSTB
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uint16_t v = getGAM(dst_mode, dst_reg, word_mode, false);
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setPSW_n(word_mode ? v & 128 : v & 32768);
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setPSW_z(v == 0);
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setPSW_v(false);
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setPSW_c(false);
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break;
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case 0b000101111: // TST/TSTB
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v = getGAM(dst_mode, dst_reg, word_mode, false);
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setPSW_n(word_mode ? v & 128 : v & 32768);
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setPSW_z(v == 0);
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setPSW_v(false);
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setPSW_c(false);
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break;
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break;
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}
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case 0b000110000: { // ROR/RORB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t t = b -> read(a, word_mode);
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bool new_carry = t & 1;
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t t = b -> read(a, word_mode);
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bool new_carry = t & 1;
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uint16_t temp = 0;
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if (word_mode) {
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@ -750,9 +766,9 @@ bool cpu::single_operand_instructions(const uint16_t instr)
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}
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case 0b000110001: { // ROL/ROLB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t t = b -> read(a, word_mode);
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bool new_carry = false;
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t t = b -> read(a, word_mode);
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bool new_carry = false;
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uint16_t temp = 0;
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if (word_mode) {
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@ -782,10 +798,10 @@ bool cpu::single_operand_instructions(const uint16_t instr)
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}
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case 0b000110010: { // ASR/ASRB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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vl = b -> read(a, word_mode);
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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int32_t vl = b -> read(a, word_mode);
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bool hb = word_mode ? vl & 128 : vl & 32768;
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bool hb = word_mode ? vl & 128 : vl & 32768;
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setPSW_c(vl & 1);
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vl >>= 1;
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@ -805,72 +821,79 @@ bool cpu::single_operand_instructions(const uint16_t instr)
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break;
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}
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case 0b00110011: // ASL/ASLB
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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vl = b -> read(a, word_mode);
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v = (vl << 1) & (word_mode ? 0xff : 0xffff);
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setPSW_n(word_mode ? v & 0x80 : v & 0x8000);
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setPSW_z(v == 0);
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setPSW_c(word_mode ? vl & 0x80 : vl & 0x8000);
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setPSW_v(getPSW_n() ^ getPSW_c());
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, v, false);
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else
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b -> write(a, word_mode, v);
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break;
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case 0b00110011: { // ASL/ASLB
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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int32_t vl = b -> read(a, word_mode);
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uint16_t v = (vl << 1) & (word_mode ? 0xff : 0xffff);
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setPSW_n(word_mode ? v & 0x80 : v & 0x8000);
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setPSW_z(v == 0);
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setPSW_c(word_mode ? vl & 0x80 : vl & 0x8000);
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setPSW_v(getPSW_n() ^ getPSW_c());
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, v, false);
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else
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b -> write(a, word_mode, v);
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break;
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}
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case 0b00110101: // MFPD/MFPI
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// FIXME
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v = getGAM(dst_mode, dst_reg, word_mode, true);
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setPSW_n(word_mode ? v & 0x80 : v & 0x8000);
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setPSW_z(v == 0);
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setPSW_v(false);
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pushStack(v);
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break;
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case 0b00110101: { // MFPD/MFPI
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// FIXME
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uint16_t v = getGAM(dst_mode, dst_reg, word_mode, true);
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setPSW_n(word_mode ? v & 0x80 : v & 0x8000);
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setPSW_z(v == 0);
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setPSW_v(false);
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pushStack(v);
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break;
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}
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case 0b00110110: // MTPI/MTPD
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// FIXME
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a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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v = popStack();
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setPSW_n(word_mode ? v & 0x80 : v & 0x8000);
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setPSW_z(v == 0);
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setPSW_v(false);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, v, true);
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else
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b -> write(a, word_mode, v); // ?
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break;
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case 0b00110110: { // MTPI/MTPD
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// FIXME
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uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
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uint16_t v = popStack();
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setPSW_n(word_mode ? v & 0x80 : v & 0x8000);
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setPSW_z(v == 0);
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setPSW_v(false);
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if (dst_mode == 0)
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putGAM(dst_mode, dst_reg, word_mode, v, true);
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else
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b -> write(a, word_mode, v); // ?
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break;
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}
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case 0b000110100: // MTPS (put something in PSW)
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psw &= 0xff00; // only alter lower 8 bits
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psw |= getGAM(dst_mode, dst_reg, word_mode, false) & 0xef; // can't change bit 4
|
||||
break;
|
||||
psw &= 0xff00; // only alter lower 8 bits
|
||||
psw |= getGAM(dst_mode, dst_reg, word_mode, false) & 0xef; // can't change bit 4
|
||||
break;
|
||||
|
||||
case 0b000110111: // MFPS (get PSW to something) / SXT
|
||||
if (word_mode) { // MFPS
|
||||
uint16_t temp = psw & 0xff;
|
||||
if (dst_mode == 0 && sign(temp))
|
||||
temp |= 0xff00;
|
||||
if (word_mode) { // MFPS
|
||||
uint16_t temp = psw & 0xff;
|
||||
|
||||
putGAM(dst_mode, dst_reg, word_mode, temp, false);
|
||||
}
|
||||
else { // SXT
|
||||
a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
|
||||
if (dst_mode == 0 && sign(temp))
|
||||
temp |= 0xff00;
|
||||
|
||||
vl = getPSW_n() ? -1 : 0;
|
||||
putGAM(dst_mode, dst_reg, word_mode, temp, false);
|
||||
}
|
||||
else { // SXT
|
||||
uint16_t a = getGAMAddress(dst_mode, dst_reg, word_mode, false);
|
||||
|
||||
setPSW_z(getPSW_n() == false);
|
||||
setPSW_v(false);
|
||||
int32_t vl = getPSW_n() ? -1 : 0;
|
||||
|
||||
if (dst_mode == 0)
|
||||
putGAM(dst_mode, dst_reg, word_mode, vl, false);
|
||||
else
|
||||
b -> write(a, word_mode, vl);
|
||||
}
|
||||
break;
|
||||
setPSW_z(getPSW_n() == false);
|
||||
setPSW_v(false);
|
||||
|
||||
if (dst_mode == 0)
|
||||
putGAM(dst_mode, dst_reg, word_mode, vl, false);
|
||||
else
|
||||
b -> write(a, word_mode, vl);
|
||||
}
|
||||
break;
|
||||
|
||||
default:
|
||||
return false;
|
||||
return false;
|
||||
}
|
||||
|
||||
return true;
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue