我可以得到簡單的asm.js代碼嗎？在使用emscripten

Question

第一個簡單的C API代碼編譯，檢查我的知識

1. C/C++代碼編譯>>（emscripten [EMCC]）>> asm.js代碼
   我能得到C/C++代碼到asm.js代碼，是不是？

2. asm.js代碼編譯>>（binaryen [asm2wasm]）>> WASM代碼
   我可以得到asm.js代碼WASM代碼，是不是？

二，我的主要問題，我怎樣才能簡單asm.js代碼？

我嘗試按照步驟，但我不能得到簡單的asm.js代碼... 我總是複雜的asm.js代碼（5000行更多...）當使用emcc編譯...

我嘗試一步

A.使簡單的C API代碼// my_add.c

#include <stdio.h> 
 
#include <emscripten.h> 
 

 
EMSCRIPTEN_KEEPALIVE 
 
double my_add(double num1, double num2) { 
 
    return num1 + num2; 
 
}

B.編譯my_add.c代碼asm.js代碼（使用EMCC）
我嘗試了很多EMCC選項...

EMCC my_add.c

EMCC my_add。 ç-s WASM = 1

等等

我的預期......簡單asm.js代碼（所以mething像後續代碼...）

function my_add(num1, num2) { 
 
    "use asm"; 
 
    num1 = num1|0; 
 
    num2 = num2|0; 
 
    retrurn (num1 + num2)|0; 
 
}

但EMCC遵守的結果是複雜的asm.js代碼

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 } 
 

 
.......

我的C/C++代碼是5〜6行..但是co mplied asm.js代碼是5000〜10000行...
我只是想簡單的'asm.js'代碼在編譯結果...
這可能嗎？
而且......我該怎麼做？

Answer 1

我找到了解決方案！

使用ONLY_MY_CODE和--separate-asm選項，

emcc my_add.c -O2 -profiling -s ONLY_MY_CODE=1 -g2 --separate-asm -o abc.js 

的abc.asm.js文件被創建：

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 
 
}; 
 
});

Answer 2

IRC ch。 #emscripten
'pdox'回答我..

PDOX：EMCC -02 -profiling

3601 function _my_add(d1, d2) { 
 
3602 d1 = +d1; 
 
3603 d2 = +d2; 
 
3604 return +(d1 + d2); 
 
3605 }

EMCC -02 -profiling

命令進行簡單的功能.. 但..但它仍然產生長（3000行...） （complie結果文件'a.out.js'是3000行....）