First, check my knowledge
c/c++ code >> compile(emscripten [emcc]) >> asm.js code
I can get c/c++ code to asm.js code, is it right?
asm.js code >> compile(binaryen [asm2wasm]) >> wasm code
I can get asm.js code to wasm code, is it right?
Second, my main question, how can i get simple asm.js code?
I'm try to follow step, but I can't get simple asm.js code... I'm get always complex asm.js code(5000 line more...) when using emcc compile...
my try step
A. make simple C api code // my_add.c
#include <stdio.h>
#include <emscripten.h>
EMSCRIPTEN_KEEPALIVE
double my_add(double num1, double num2) {
return num1 + num2;
}
B. compile my_add.c code to asm.js code (using emcc)
I'm try many emcc options...
emcc my_add.c
emcc my_add.c -s WASM=1
etc...
My expected... simple asm.js code (something like follow code...)
function my_add(num1, num2) {
"use asm";
num1 = num1|0;
num2 = num2|0;
retrurn (num1 + num2)|0;
}
But emcc complied result is complex asm.js code
1 // The Module object: Our interface to the outside world. We import
2 // and export values on it, and do the work to get that through
3 // closure compiler if necessary. There are various ways Module can be used:
4 // 1. Not defined. We create it here
5 // 2. A function parameter, function(Module) { ..generated code.. }
6 // 3. pre-run appended it, var Module = {}; ..generated code..
7 // 4. External script tag defines var Module.
8 // We need to do an eval in order to handle the closure compiler
9 // case, where this code here is minified but Module was defined
10 // elsewhere (e.g. case 4 above). We also need to check if Module
11 // already exists (e.g. case 3 above).
12 // Note that if you want to run closure, and also to use Module
13 // after the generated code, you will need to define var Module = {};
14 // before the code. Then that object will be used in the code, and you
15 // can continue to use Module afterwards as well.
16 var Module;
17 if (!Module) Module = (typeof Module !== 'undefined' ? Module : null) || {};
18
19 // Sometimes an existing Module object exists with properties
20 // meant to overwrite the default module functionality. Here
21 // we collect those properties and reapply _after_ we configure
22 // the current environment's defaults to avoid having to be so
23 // defensive during initialization.
24 var moduleOverrides = {};
25 for (var key in Module) {
26 if (Module.hasOwnProperty(key)) {
27 moduleOverrides[key] = Module[key];
28 }
29 }
30
31 // The environment setup code below is customized to use Module.
32 // *** Environment setup code ***
33 var ENVIRONMENT_IS_WEB = false;
34 var ENVIRONMENT_IS_WORKER = false;
35 var ENVIRONMENT_IS_NODE = false;
36 var ENVIRONMENT_IS_SHELL = false;
37
......
2038 function _my_add($num1,$num2) {
2039 $num1 = +$num1;
2040 $num2 = +$num2;
2041 var $0 = 0.0, $1 = 0.0, $2 = 0.0, $3 = 0.0, $4 = 0.0, label = 0, sp = 0;
2042 sp = STACKTOP;
2043 STACKTOP = STACKTOP + 16|0; if ((STACKTOP|0) >= (STACK_MAX|0)) abort();
2044 $0 = $num1;
2045 $1 = $num2;
2046 $2 = $0;
2047 $3 = $1;
2048 $4 = $2 + $3;
2049 STACKTOP = sp;return (+$4);
2050 }
.......
My C/C++ code is 5~6 line.. but complied asm.js code is 5000~10000 line...
I'm just want simple 'asm.js' code at compile result...
Is It possible?
And... How can I do that?
I have found a solution!
Using the ONLY_MY_CODE
and --separate-asm
options,
emcc my_add.c -O2 -profiling -s ONLY_MY_CODE=1 -g2 --separate-asm -o abc.js
the abc.asm.js
file is created:
Module["asm"] = (function(global, env, buffer) {
"use asm";
function _my_add(d1, d2) {
d1 = +d1;
d2 = +d2;
return +(d1 + d2);
}
return {
_my_add: _my_add
};
});