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8bitworkshop/gen/common/analysis.js

255 lines
9.8 KiB
JavaScript

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.CodeAnalyzer_apple2 = exports.CodeAnalyzer_nes = exports.CodeAnalyzer_vcs = void 0;
const util_1 = require("./util");
/// VCS TIMING ANALYSIS
// [taken, not taken]
const BRANCH_CONSTRAINTS = [
[{ N: 0 }, { N: 1 }],
[{ N: 1 }, { N: 0 }],
[{ V: 0 }, { V: 1 }],
[{ V: 1 }, { V: 0 }],
[{ C: 0 }, { C: 1 }],
[{ C: 1 }, { C: 0 }],
[{ Z: 0 }, { Z: 1 }],
[{ Z: 1 }, { Z: 0 }]
];
function constraintEquals(a, b) {
if (a == null || b == null)
return null;
for (var n in a) {
if (b[n] !== 'undefined')
return a[n] == b[n];
}
for (var n in b) {
if (a[n] !== 'undefined')
return a[n] == b[n];
}
return null;
}
class CodeAnalyzer6502 {
constructor(platform) {
this.pc2minclocks = {};
this.pc2maxclocks = {};
this.jsrresult = {};
this.MAX_CYCLES = 2000;
this.platform = platform;
}
getClockCountsAtPC(pc) {
var opcode = this.platform.readAddress(pc);
var meta = this.platform.getOpcodeMetadata(opcode, pc);
return meta; // minCycles, maxCycles
}
traceInstructions(pc, minclocks, maxclocks, subaddr, constraints) {
if (this.WRAP_CLOCKS) {
if (this.pc2minclocks[pc] !== undefined)
minclocks = Math.min(minclocks, this.pc2minclocks[pc]);
if (this.pc2maxclocks[pc] !== undefined)
maxclocks = Math.max(maxclocks, this.pc2maxclocks[pc]);
}
//console.log("trace", hex(pc), minclocks, maxclocks);
if (!constraints)
constraints = {};
var modified = true;
var abort = false;
for (var i = 0; modified && !abort; i++) {
if (i >= this.MAX_CYCLES) {
console.log("too many cycles @", (0, util_1.hex)(pc), "routine", (0, util_1.hex)(subaddr));
break;
}
modified = false;
if (this.WRAP_CLOCKS && minclocks >= this.MAX_CLOCKS) {
// wrap clocks
minclocks = minclocks % this.MAX_CLOCKS;
maxclocks = maxclocks % this.MAX_CLOCKS;
}
else {
// truncate clocks
minclocks = Math.min(this.MAX_CLOCKS, minclocks);
maxclocks = Math.min(this.MAX_CLOCKS, maxclocks);
}
var meta = this.getClockCountsAtPC(pc);
var lob = this.platform.readAddress(pc + 1);
var hib = this.platform.readAddress(pc + 2);
var addr = lob + (hib << 8);
var pc0 = pc;
if (!(minclocks >= this.pc2minclocks[pc0])) {
this.pc2minclocks[pc0] = minclocks;
modified = true;
}
if (!(maxclocks <= this.pc2maxclocks[pc0])) {
this.pc2maxclocks[pc0] = maxclocks;
modified = true;
}
//console.log(hex(pc),minclocks,maxclocks,modified,meta,constraints);
if (!meta.insnlength) {
console.log("Illegal instruction!", (0, util_1.hex)(pc), (0, util_1.hex)(meta.opcode), meta);
break;
}
pc += meta.insnlength;
var oldconstraints = constraints;
constraints = null;
// TODO: if jump to zero-page, maybe assume RTS?
switch (meta.opcode) {
case 0x19:
case 0x1d:
case 0x39:
case 0x3d:
case 0x59:
case 0x5d:
case 0x79:
case 0x7d:
case 0x99:
case 0x9d:
case 0xa9:
case 0xad:
case 0xb9:
case 0xbd:
case 0xbc:
case 0xbe:
case 0xd9:
case 0xdd:
case 0xf9:
case 0xfd:
if (lob == 0)
meta.maxCycles -= 1; // no page boundary crossed
break;
// TODO: only VCS
case 0x85:
if (lob == 0x2) { // STA WSYNC
minclocks = maxclocks = 0;
meta.minCycles = meta.maxCycles = 0;
}
break;
// TODO: only NES (sprite 0 poll)
case 0x2c:
if (lob == 0x02 && hib == 0x20) { // BIT $2002
minclocks = 0;
maxclocks = 4; // uncertainty b/c of assumed branch poll
meta.minCycles = meta.maxCycles = 0;
}
break;
// TODO: only Apple2 (vapor lock)
/*
case 0xad:
if (lob == 0x61 && hib == 0xc0) { // LDA $C061
minclocks = 0;
maxclocks = 4; // uncertainty?
meta.minCycles = meta.maxCycles = 0;
}
break;
*/
case 0x20: // JSR
// TODO: handle bare RTS case
minclocks += meta.minCycles;
maxclocks += meta.maxCycles;
this.traceInstructions(addr, minclocks, maxclocks, addr, constraints);
var result = this.jsrresult[addr];
if (result) {
minclocks = result.minclocks;
maxclocks = result.maxclocks;
}
else {
console.log("No JSR result!", (0, util_1.hex)(pc), (0, util_1.hex)(addr));
minclocks = maxclocks;
//return;
}
break;
case 0x4c: // JMP
pc = addr; // TODO: make sure in ROM space
break;
case 0x40: // RTI
abort = true;
break;
case 0x60: // RTS
if (subaddr) { // TODO: 0 doesn't work
// TODO: combine with previous result
var result = this.jsrresult[subaddr];
if (!result) {
result = { minclocks: minclocks, maxclocks: maxclocks };
}
else {
result = {
minclocks: Math.min(minclocks, result.minclocks),
maxclocks: Math.max(maxclocks, result.maxclocks)
};
}
this.jsrresult[subaddr] = result;
console.log("RTS", (0, util_1.hex)(pc), (0, util_1.hex)(subaddr), this.jsrresult[subaddr]);
}
return;
case 0x10:
case 0x30: // branch
case 0x50:
case 0x70:
case 0x90:
case 0xB0:
case 0xD0:
case 0xF0:
var newpc = pc + (0, util_1.byte2signed)(lob);
var crosspage = (pc >> 8) != (newpc >> 8);
if (!crosspage)
meta.maxCycles--;
// TODO: other instructions might modify flags too
var cons = BRANCH_CONSTRAINTS[Math.floor((meta.opcode - 0x10) / 0x20)];
var cons0 = constraintEquals(oldconstraints, cons[0]);
var cons1 = constraintEquals(oldconstraints, cons[1]);
// recursively trace the taken branch
if (true || cons0 !== false) { // TODO?
this.traceInstructions(newpc, minclocks + meta.maxCycles, maxclocks + meta.maxCycles, subaddr, cons[0]);
}
// abort if we will always take the branch
if (cons1 === false) {
console.log("branch always taken", (0, util_1.hex)(pc), oldconstraints, cons[1]);
abort = true;
}
constraints = cons[1]; // not taken
meta.maxCycles = meta.minCycles; // branch not taken, no extra clock(s)
break;
case 0x6c:
console.log("Instruction not supported!", (0, util_1.hex)(pc), (0, util_1.hex)(meta.opcode), meta); // TODO
return;
}
// add min/max instruction time to min/max clocks bound
minclocks += meta.minCycles;
maxclocks += meta.maxCycles;
}
}
showLoopTimingForPC(pc) {
this.pc2minclocks = {};
this.pc2maxclocks = {};
this.jsrresult = {};
// recurse through all traces
this.traceInstructions(pc | this.platform.getOriginPC(), this.START_CLOCKS, this.MAX_CLOCKS, 0, {});
}
}
// 76 cycles * 2 (support two scanline kernels)
class CodeAnalyzer_vcs extends CodeAnalyzer6502 {
constructor(platform) {
super(platform);
this.MAX_CLOCKS = this.START_CLOCKS = 76 * 4; // 4 scanlines
this.WRAP_CLOCKS = false;
}
}
exports.CodeAnalyzer_vcs = CodeAnalyzer_vcs;
// https://wiki.nesdev.com/w/index.php/PPU_rendering#Line-by-line_timing
// TODO: sprite 0 hit, CPU stalls
class CodeAnalyzer_nes extends CodeAnalyzer6502 {
constructor(platform) {
super(platform);
this.MAX_CLOCKS = 114; // 341 clocks for 3 scanlines
this.START_CLOCKS = 0;
this.WRAP_CLOCKS = true;
}
}
exports.CodeAnalyzer_nes = CodeAnalyzer_nes;
class CodeAnalyzer_apple2 extends CodeAnalyzer6502 {
constructor(platform) {
super(platform);
this.MAX_CLOCKS = 65;
this.START_CLOCKS = 0;
this.WRAP_CLOCKS = true;
}
}
exports.CodeAnalyzer_apple2 = CodeAnalyzer_apple2;
//# sourceMappingURL=analysis.js.map