[08] Optimized function starts a little

master
Nemo 3 years ago
parent 6bdbec501a
commit 5160559eff
  1. 14
      projects/08/ProgramFlow/FibonacciSeries/FibonacciSeries.asm
  2. 38
      vm/CodeWriter.php
  3. 3
      vm/VMTranslator.php

@ -1,3 +1,15 @@
@256 // init starts
D=A
@SP
M=D // initialized SP to 256
@300
D=A
@LCL
M=D // initialized @LCL to 300
@400
D=A
@ARG
M=D // initialized @ARG to 400, init ends
@ARG // argument 1
D=M
@1 // write 1 to A
@ -192,5 +204,5 @@ M=D // end pop argument 0 (L26)
@__GLOBAL__.MAIN_LOOP_START
0;JMP // end goto MAIN_LOOP_START (L27)
(__GLOBAL__.END_PROGRAM) // end label END_PROGRAM (L28)
@195
@207
0;JMP

@ -10,6 +10,9 @@ class CodeWriter {
// We aren't inside a function by default
$this->fn = null;
// Write the preamble for the assembler
$this->writeInit();
}
public function writeReturn() {
@ -76,18 +79,35 @@ class CodeWriter {
]);
}
/**
* Translates the "function" start.
* function $name $args
*/
public function writeFunction($name, $numArgs) {
// This is used for labels within the current function
$this->fn = $name;
$this->write([
"($name) // function $name $numArgs",
]);
// We write this once at the top
// And for subsequent loops, we can re-use
// the @SP call at the end where we bump the stack by 1
if ($numArgs > 0) {
$this->write([
// This is only required for the first argument
"@SP", "A=M"
]);
}
// For every argument in the function
// push a zero to the stack
for($i=0;$i<$numArgs;$i++) {
$this->write([
"M=0",
"@SP",
"A=M",
"M=D",
"@SP",
"M=M+1"
"AM=M+1",
]);
}
}
@ -97,7 +117,7 @@ class CodeWriter {
*/
private function writeInit() {
$this->write([
"@256",
"@256 // init starts",
"D=A",
"@SP",
"M=D // initialized SP to 256",
@ -108,7 +128,10 @@ class CodeWriter {
"@400",
"D=A",
"@ARG",
"M=D // initialized @ARG to 400",
"M=D // initialized @ARG to 400, init ends",
// We jump to Sys.init
"@Sys.init",
"0;JMP"
]);
}
@ -486,6 +509,9 @@ class CodeWriter {
}
}
/**
* Resolves pointer [0|1] to the this|that register
*/
private function resolvePointer(Int $index) {
return $index == 0 ? '@THIS' : '@THAT';
}

@ -27,11 +27,14 @@ class VMTranslator {
*/
function translate() {
foreach ($this->files as $file) {
$parser = new Parser($file);
$this->writer->setInputFileName($file);
foreach ($parser->commands() as $command) {
$commandType = CommandType::fromName($command);
switch ($commandType) {
case CommandType::ARITHMETIC:
$this->writer->writeArithmetic($command);

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