mirror of
https://github.com/TomHarte/CLK.git
synced 2024-11-26 23:52:26 +00:00
348 lines
16 KiB
C++
348 lines
16 KiB
C++
//
|
|
// Decoder.cpp
|
|
// Clock Signal
|
|
//
|
|
// Created by Thomas Harte on 30/12/20.
|
|
// Copyright © 2020 Thomas Harte. All rights reserved.
|
|
//
|
|
|
|
#include "Decoder.hpp"
|
|
|
|
using namespace InstructionSet::PowerPC;
|
|
|
|
Decoder::Decoder(Model model) : model_(model) {}
|
|
|
|
Instruction Decoder::decode(uint32_t opcode) {
|
|
// Quick bluffer's guide to PowerPC instruction encoding:
|
|
//
|
|
// There is a six-bit field at the very top of the instruction.
|
|
// Sometimes that fully identifies an instruction, but usually
|
|
// it doesn't.
|
|
//
|
|
// There is an addition 9- or 10-bit field starting one bit above
|
|
// least significant that disambiguates the rest. Strictly speaking
|
|
// it's a 10-bit field, but the mnemonics for many instructions treat
|
|
// it as a 9-bit field with a flag at the top.
|
|
//
|
|
// I've decided to hew directly to the mnemonics.
|
|
//
|
|
// Various opcodes in the 1995 documentation define reserved bits,
|
|
// which are given the nominal value of 0. It does not give a formal
|
|
// definition of a reserved bit. As a result this code does not
|
|
// currently check the value of reserved bits. That may need to change
|
|
// if/when I add support for extended instruction sets.
|
|
|
|
#define Bind(mask, operation) case mask: return Instruction(Operation::operation, opcode);
|
|
#define BindSupervisor(mask, operation) case mask: return Instruction(Operation::operation, opcode, true);
|
|
#define BindConditional(condition, mask, operation) \
|
|
case mask: \
|
|
if(condition()) return Instruction(Operation::operation, opcode); \
|
|
return Instruction(opcode);
|
|
#define BindSupervisorConditional(condition, mask, operation) \
|
|
case mask: \
|
|
if(condition()) return Instruction(Operation::operation, opcode, true); \
|
|
return Instruction(opcode);
|
|
|
|
#define Six(x) (unsigned(x) << 26)
|
|
#define SixTen(x, y) (Six(x) | ((y) << 1))
|
|
|
|
// First pass: weed out all those instructions identified entirely by the
|
|
// top six bits.
|
|
switch(opcode & Six(0b111111)) {
|
|
default: break;
|
|
|
|
BindConditional(is64bit, Six(0b000010), tdi);
|
|
|
|
Bind(Six(0b000011), twi);
|
|
Bind(Six(0b000111), mulli);
|
|
Bind(Six(0b001000), subfic);
|
|
Bind(Six(0b001100), addic); Bind(Six(0b001101), addic_);
|
|
Bind(Six(0b001110), addi); Bind(Six(0b001111), addis);
|
|
case Six(0b010000): {
|
|
// This might be a bcx, but check for a valid bo field.
|
|
switch((opcode >> 21) & 0x1f) {
|
|
case 0: case 1: case 2: case 3: case 4: case 5:
|
|
case 8: case 9: case 10: case 11: case 12: case 13:
|
|
case 16: case 17: case 18: case 19: case 20:
|
|
return Instruction(Operation::bcx, opcode);
|
|
|
|
default: return Instruction(opcode);
|
|
}
|
|
} break;
|
|
Bind(Six(0b010010), bx);
|
|
Bind(Six(0b010100), rlwimix);
|
|
Bind(Six(0b010101), rlwinmx);
|
|
Bind(Six(0b010111), rlwnmx);
|
|
|
|
Bind(Six(0b011000), ori); Bind(Six(0b011001), oris);
|
|
Bind(Six(0b011010), xori); Bind(Six(0b011011), xoris);
|
|
Bind(Six(0b011100), andi_); Bind(Six(0b011101), andis_);
|
|
Bind(Six(0b100000), lwz); Bind(Six(0b100001), lwzu);
|
|
Bind(Six(0b100010), lbz); Bind(Six(0b100011), lbzu);
|
|
Bind(Six(0b100100), stw); Bind(Six(0b100101), stwu);
|
|
Bind(Six(0b100110), stb); Bind(Six(0b100111), stbu);
|
|
Bind(Six(0b101000), lhz); Bind(Six(0b101001), lhzu);
|
|
Bind(Six(0b101010), lha); Bind(Six(0b101011), lhau);
|
|
Bind(Six(0b101100), sth); Bind(Six(0b101101), sthu);
|
|
Bind(Six(0b101110), lmw); Bind(Six(0b101111), stmw);
|
|
Bind(Six(0b110000), lfs); Bind(Six(0b110001), lfsu);
|
|
Bind(Six(0b110010), lfd); Bind(Six(0b110011), lfdu);
|
|
Bind(Six(0b110100), stfs); Bind(Six(0b110101), stfsu);
|
|
Bind(Six(0b110110), stfd); Bind(Six(0b110111), stfdu);
|
|
|
|
BindConditional(is601, Six(9), dozi);
|
|
BindConditional(is601, Six(22), rlmix);
|
|
|
|
Bind(Six(0b001010), cmpli); Bind(Six(0b001011), cmpi);
|
|
}
|
|
|
|
// Second pass: all those with a top six bits and a bottom nine or ten.
|
|
switch(opcode & SixTen(0b111111, 0b1111111111)) {
|
|
default: break;
|
|
|
|
// 64-bit instructions.
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0000001001), mulhdux); BindConditional(is64bit, SixTen(0b011111, 0b1000001001), mulhdux);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0000010101), ldx);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0000011011), sldx);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0000110101), ldux);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0000111010), cntlzdx);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0001000100), td);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0001001001), mulhdx); BindConditional(is64bit, SixTen(0b011111, 0b1001001001), mulhdx);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0001010100), ldarx);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0010010101), stdx);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0010110101), stdux);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0011101001), mulld); BindConditional(is64bit, SixTen(0b011111, 0b1011101001), mulld);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0101010101), lwax);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0101110101), lwaux);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b1100111011), sradix); BindConditional(is64bit, SixTen(0b011111, 0b1100111010), sradix);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0110110010), slbie);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0111001001), divdux); BindConditional(is64bit, SixTen(0b011111, 0b1111001001), divdux);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b0111101001), divdx); BindConditional(is64bit, SixTen(0b011111, 0b1111101001), divdx);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b1000011011), srdx);
|
|
BindConditional(is64bit, SixTen(0b011111, 0b1100011010), sradx);
|
|
BindConditional(is64bit, SixTen(0b111111, 0b1111011010), extsw);
|
|
|
|
// Power instructions; these are all taken from the MPC601 manual rather than
|
|
// the PowerPC Programmer's Reference Guide, hence the decimal encoding of the
|
|
// ten-bit field.
|
|
BindConditional(is601, SixTen(0b011111, 360), absx); BindConditional(is601, SixTen(0b011111, 512 + 360), absx);
|
|
BindConditional(is601, SixTen(0b011111, 531), clcs);
|
|
BindConditional(is601, SixTen(0b011111, 331), divx); BindConditional(is601, SixTen(0b011111, 512 + 331), divx);
|
|
BindConditional(is601, SixTen(0b011111, 363), divsx); BindConditional(is601, SixTen(0b011111, 512 + 363), divsx);
|
|
BindConditional(is601, SixTen(0b011111, 264), dozx); BindConditional(is601, SixTen(0b011111, 512 + 264), dozx);
|
|
BindConditional(is601, SixTen(0b011111, 277), lscbxx);
|
|
BindConditional(is601, SixTen(0b011111, 29), maskgx);
|
|
BindConditional(is601, SixTen(0b011111, 541), maskirx);
|
|
BindConditional(is601, SixTen(0b011111, 107), mulx); BindConditional(is601, SixTen(0b011111, 512 + 107), mulx);
|
|
BindConditional(is601, SixTen(0b011111, 488), nabsx); BindConditional(is601, SixTen(0b011111, 512 + 488), nabsx);
|
|
BindConditional(is601, SixTen(0b011111, 537), rribx);
|
|
BindConditional(is601, SixTen(0b011111, 153), slex);
|
|
BindConditional(is601, SixTen(0b011111, 217), sleqx);
|
|
BindConditional(is601, SixTen(0b011111, 184), sliqx);
|
|
BindConditional(is601, SixTen(0b011111, 248), slliqx);
|
|
BindConditional(is601, SixTen(0b011111, 216), sllqx);
|
|
BindConditional(is601, SixTen(0b011111, 152), slqx);
|
|
BindConditional(is601, SixTen(0b011111, 952), sraiqx);
|
|
BindConditional(is601, SixTen(0b011111, 920), sraqx);
|
|
BindConditional(is601, SixTen(0b011111, 665), srex);
|
|
BindConditional(is601, SixTen(0b011111, 921), sreax);
|
|
BindConditional(is601, SixTen(0b011111, 729), sreqx);
|
|
BindConditional(is601, SixTen(0b011111, 696), sriqx);
|
|
BindConditional(is601, SixTen(0b011111, 760), srliqx);
|
|
BindConditional(is601, SixTen(0b011111, 728), srlqx);
|
|
BindConditional(is601, SixTen(0b011111, 664), srqx);
|
|
|
|
// 32-bit instructions.
|
|
Bind(SixTen(0b010011, 0b0000000000), mcrf);
|
|
Bind(SixTen(0b010011, 0b0000010000), bclrx);
|
|
Bind(SixTen(0b010011, 0b0000100001), crnor);
|
|
Bind(SixTen(0b010011, 0b0000110010), rfi);
|
|
Bind(SixTen(0b010011, 0b0010000001), crandc);
|
|
Bind(SixTen(0b010011, 0b0010010110), isync);
|
|
Bind(SixTen(0b010011, 0b0011000001), crxor);
|
|
Bind(SixTen(0b010011, 0b0011100001), crnand);
|
|
Bind(SixTen(0b010011, 0b0100000001), crand);
|
|
Bind(SixTen(0b010011, 0b0100100001), creqv);
|
|
Bind(SixTen(0b010011, 0b0110100001), crorc);
|
|
Bind(SixTen(0b010011, 0b0111000001), cror);
|
|
Bind(SixTen(0b010011, 0b1000010000), bcctrx);
|
|
Bind(SixTen(0b011111, 0b0000000000), cmp);
|
|
Bind(SixTen(0b011111, 0b0000000100), tw);
|
|
Bind(SixTen(0b011111, 0b0000001000), subfcx); Bind(SixTen(0b011111, 0b1000001000), subfcx);
|
|
Bind(SixTen(0b011111, 0b0000001010), addcx); Bind(SixTen(0b011111, 0b1000001010), addcx);
|
|
Bind(SixTen(0b011111, 0b0000001011), mulhwux); Bind(SixTen(0b011111, 0b1000001011), mulhwux);
|
|
Bind(SixTen(0b011111, 0b0000010011), mfcr);
|
|
Bind(SixTen(0b011111, 0b0000010100), lwarx);
|
|
Bind(SixTen(0b011111, 0b0000010111), lwzx);
|
|
Bind(SixTen(0b011111, 0b0000011000), slwx);
|
|
Bind(SixTen(0b011111, 0b0000011010), cntlzwx);
|
|
Bind(SixTen(0b011111, 0b0000011100), andx);
|
|
Bind(SixTen(0b011111, 0b0000100000), cmpl);
|
|
Bind(SixTen(0b011111, 0b0000101000), subfx); Bind(SixTen(0b011111, 0b1000101000), subfx);
|
|
Bind(SixTen(0b011111, 0b0000110110), dcbst);
|
|
Bind(SixTen(0b011111, 0b0000110111), lwzux);
|
|
Bind(SixTen(0b011111, 0b0000111100), andcx);
|
|
Bind(SixTen(0b011111, 0b0001001011), mulhwx); Bind(SixTen(0b011111, 0b1001001011), mulhwx);
|
|
Bind(SixTen(0b011111, 0b0001010011), mfmsr);
|
|
Bind(SixTen(0b011111, 0b0001010110), dcbf);
|
|
Bind(SixTen(0b011111, 0b0001010111), lbzx);
|
|
Bind(SixTen(0b011111, 0b0001101000), negx); Bind(SixTen(0b011111, 0b1001101000), negx);
|
|
Bind(SixTen(0b011111, 0b0001110111), lbzux);
|
|
Bind(SixTen(0b011111, 0b0001111100), norx);
|
|
Bind(SixTen(0b011111, 0b0010001000), subfex); Bind(SixTen(0b011111, 0b1010001000), subfex);
|
|
Bind(SixTen(0b011111, 0b0010001010), addex); Bind(SixTen(0b011111, 0b1010001010), addex);
|
|
Bind(SixTen(0b011111, 0b0010010000), mtcrf);
|
|
Bind(SixTen(0b011111, 0b0010010010), mtmsr);
|
|
Bind(SixTen(0b011111, 0b0010010111), stwx);
|
|
Bind(SixTen(0b011111, 0b0010110111), stwux);
|
|
Bind(SixTen(0b011111, 0b0011001000), subfzex); Bind(SixTen(0b011111, 0b1011001000), subfzex);
|
|
Bind(SixTen(0b011111, 0b0011001010), addzex); Bind(SixTen(0b011111, 0b1011001010), addzex);
|
|
Bind(SixTen(0b011111, 0b0011010111), stbx);
|
|
Bind(SixTen(0b011111, 0b0011101000), subfmex); Bind(SixTen(0b011111, 0b1011101000), subfmex);
|
|
Bind(SixTen(0b011111, 0b0011101010), addmex); Bind(SixTen(0b011111, 0b1011101010), addmex);
|
|
Bind(SixTen(0b011111, 0b0011101011), mullwx); Bind(SixTen(0b011111, 0b1011101011), mullwx);
|
|
Bind(SixTen(0b011111, 0b0011110110), dcbtst);
|
|
Bind(SixTen(0b011111, 0b0011110111), stbux);
|
|
Bind(SixTen(0b011111, 0b0100001010), addx); Bind(SixTen(0b011111, 0b1100001010), addx);
|
|
Bind(SixTen(0b011111, 0b0100010110), dcbt);
|
|
Bind(SixTen(0b011111, 0b0100010111), lhzx);
|
|
Bind(SixTen(0b011111, 0b0100011100), eqvx);
|
|
Bind(SixTen(0b011111, 0b0100110110), eciwx);
|
|
Bind(SixTen(0b011111, 0b0100110111), lhzux);
|
|
Bind(SixTen(0b011111, 0b0100111100), xorx);
|
|
Bind(SixTen(0b011111, 0b0101010111), lhax);
|
|
Bind(SixTen(0b011111, 0b0101110011), mftb);
|
|
Bind(SixTen(0b011111, 0b0101110111), lhaux);
|
|
Bind(SixTen(0b011111, 0b0110010111), sthx);
|
|
Bind(SixTen(0b011111, 0b0110011100), orcx);
|
|
Bind(SixTen(0b011111, 0b0110110110), ecowx);
|
|
Bind(SixTen(0b011111, 0b0110110111), sthux);
|
|
Bind(SixTen(0b011111, 0b0110111100), orx);
|
|
Bind(SixTen(0b011111, 0b0111001011), divwux); Bind(SixTen(0b011111, 0b1111001011), divwux);
|
|
Bind(SixTen(0b011111, 0b0111010110), dcbi);
|
|
Bind(SixTen(0b011111, 0b0111011100), nandx);
|
|
Bind(SixTen(0b011111, 0b0111101011), divwx); Bind(SixTen(0b011111, 0b1111101011), divwx);
|
|
Bind(SixTen(0b011111, 0b1000000000), mcrxr);
|
|
Bind(SixTen(0b011111, 0b1000010101), lswx);
|
|
Bind(SixTen(0b011111, 0b1000010110), lwbrx);
|
|
Bind(SixTen(0b011111, 0b1000010111), lfsx);
|
|
Bind(SixTen(0b011111, 0b1000011000), srwx);
|
|
Bind(SixTen(0b011111, 0b1000110111), lfsux);
|
|
Bind(SixTen(0b011111, 0b1001010101), lswi);
|
|
Bind(SixTen(0b011111, 0b1001010110), sync);
|
|
Bind(SixTen(0b011111, 0b1001010111), lfdx);
|
|
Bind(SixTen(0b011111, 0b1001110111), lfdux);
|
|
Bind(SixTen(0b011111, 0b1010010101), stswx);
|
|
Bind(SixTen(0b011111, 0b1010010110), stwbrx);
|
|
Bind(SixTen(0b011111, 0b1010010111), stfsx);
|
|
Bind(SixTen(0b011111, 0b1010110111), stfsux);
|
|
Bind(SixTen(0b011111, 0b1011010101), stswi);
|
|
Bind(SixTen(0b011111, 0b1011010111), stfdx);
|
|
Bind(SixTen(0b011111, 0b1011110111), stfdux);
|
|
Bind(SixTen(0b011111, 0b1100010110), lhbrx);
|
|
Bind(SixTen(0b011111, 0b1100011000), srawx);
|
|
Bind(SixTen(0b011111, 0b1100111000), srawix);
|
|
Bind(SixTen(0b011111, 0b1101010110), eieio);
|
|
Bind(SixTen(0b011111, 0b1110010110), sthbrx);
|
|
Bind(SixTen(0b011111, 0b1110011010), extshx);
|
|
Bind(SixTen(0b011111, 0b1110111010), extsbx);
|
|
Bind(SixTen(0b011111, 0b1111010110), icbi);
|
|
Bind(SixTen(0b011111, 0b1111010111), stfiwx);
|
|
Bind(SixTen(0b011111, 0b1111110110), dcbz);
|
|
Bind(SixTen(0b111111, 0b0000000000), fcmpu);
|
|
Bind(SixTen(0b111111, 0b0000001100), frspx);
|
|
Bind(SixTen(0b111111, 0b0000001110), fctiwx);
|
|
Bind(SixTen(0b111111, 0b0000001111), fctiwzx);
|
|
Bind(SixTen(0b111111, 0b0000100000), fcmpo);
|
|
Bind(SixTen(0b111111, 0b0000100110), mtfsb1x);
|
|
Bind(SixTen(0b111111, 0b0000101000), fnegx);
|
|
Bind(SixTen(0b111111, 0b0001000000), mcrfs);
|
|
Bind(SixTen(0b111111, 0b0001000110), mtfsb0x);
|
|
Bind(SixTen(0b111111, 0b0001001000), fmrx);
|
|
Bind(SixTen(0b111111, 0b0010000110), mtfsfix);
|
|
Bind(SixTen(0b111111, 0b0010001000), fnabsx);
|
|
Bind(SixTen(0b111111, 0b0100001000), fabsx);
|
|
Bind(SixTen(0b111111, 0b1001000111), mffsx);
|
|
Bind(SixTen(0b111111, 0b1011000111), mtfsfx);
|
|
Bind(SixTen(0b111111, 0b1100101110), fctidx);
|
|
Bind(SixTen(0b111111, 0b1100101111), fctidzx);
|
|
Bind(SixTen(0b111111, 0b1101001110), fcfidx);
|
|
|
|
Bind(SixTen(0b011111, 0b0101010011), mfspr); // Flagged as "supervisor and user"?
|
|
Bind(SixTen(0b011111, 0b0111010011), mtspr); // Flagged as "supervisor and user"?
|
|
|
|
BindSupervisorConditional(is32bit, SixTen(0b011111, 0b0011010010), mtsr);
|
|
BindSupervisorConditional(is32bit, SixTen(0b011111, 0b0011110010), mtsrin);
|
|
BindSupervisorConditional(is32bit, SixTen(0b011111, 0b1001010011), mfsr);
|
|
BindSupervisorConditional(is32bit, SixTen(0b011111, 0b1010010011), mfsrin);
|
|
|
|
BindSupervisorConditional(is64bit, SixTen(0b011111, 0b0111110010), slbia); // optional
|
|
|
|
// The following are all optional; should I record that?
|
|
BindSupervisor(SixTen(0b011111, 0b0100110010), tlbie);
|
|
BindSupervisor(SixTen(0b011111, 0b0101110010), tlbia);
|
|
BindSupervisor(SixTen(0b011111, 0b1000110110), tlbsync);
|
|
}
|
|
|
|
// Third pass: like six-ten except that the top five of the final ten
|
|
// are reserved (i.e. ignored here).
|
|
switch(opcode & SixTen(0b111111, 0b11111)) {
|
|
default: break;
|
|
|
|
Bind(SixTen(0b111011, 0b10010), fdivsx);
|
|
Bind(SixTen(0b111011, 0b10100), fsubsx);
|
|
Bind(SixTen(0b111011, 0b10101), faddsx);
|
|
Bind(SixTen(0b111011, 0b11001), fmulsx);
|
|
Bind(SixTen(0b111011, 0b11100), fmsubsx);
|
|
Bind(SixTen(0b111011, 0b11101), fmaddsx);
|
|
Bind(SixTen(0b111011, 0b11110), fnmsubsx);
|
|
Bind(SixTen(0b111011, 0b11111), fnmaddsx);
|
|
|
|
Bind(SixTen(0b111111, 0b10010), fdivx);
|
|
Bind(SixTen(0b111111, 0b10100), fsubx);
|
|
Bind(SixTen(0b111111, 0b10101), faddx);
|
|
Bind(SixTen(0b111111, 0b11001), fmulx);
|
|
Bind(SixTen(0b111111, 0b11100), fmsubx);
|
|
Bind(SixTen(0b111111, 0b11101), fmaddx);
|
|
Bind(SixTen(0b111111, 0b11110), fnmsubx);
|
|
Bind(SixTen(0b111111, 0b11111), fnmaddx);
|
|
|
|
BindConditional(is64bit, SixTen(0b111011, 0b10110), fsqrtsx);
|
|
BindConditional(is64bit, SixTen(0b111011, 0b11000), fresx);
|
|
|
|
// Optional...
|
|
Bind(SixTen(0b111111, 0b10110), fsqrtx);
|
|
Bind(SixTen(0b111111, 0b10111), fselx);
|
|
Bind(SixTen(0b111111, 0b11010), frsqrtex);
|
|
}
|
|
|
|
// stwcx. and stdcx.
|
|
switch(opcode & 0b111111'00'00000000'000'111111111'1){
|
|
case 0b011111'00'00000000'00000'0010010110'1: return Instruction(Operation::stwcx_, opcode);
|
|
case 0b011111'00'00000000'00000'0011010110'1:
|
|
if(is64bit()) return Instruction(Operation::stdcx_, opcode);
|
|
return Instruction(opcode);
|
|
}
|
|
|
|
// std and stdu
|
|
switch(opcode & 0b111111'00'00000000'00000000'000000'11){
|
|
case 0b111110'00'00000000'00000000'000000'00: return Instruction(Operation::std, opcode);
|
|
case 0b111110'00'00000000'00000000'000000'01:
|
|
if(is64bit()) return Instruction(Operation::stdu, opcode);
|
|
return Instruction(opcode);
|
|
}
|
|
|
|
// sc
|
|
if((opcode & 0b111111'00'00000000'00000000'000000'1'0) == 0b010001'00'00000000'00000000'000000'1'0) {
|
|
return Instruction(Operation::sc, opcode);
|
|
}
|
|
|
|
#undef Six
|
|
#undef SixTen
|
|
|
|
#undef Bind
|
|
#undef BindConditional
|
|
|
|
return Instruction(opcode);
|
|
}
|