CODEWITHSUNDEEP
javascriptfirefoxasm.js
Syntax
Syntax

Reputation: 2103

Unable to work around Firefox's AMS.js link restriction

I received the error: 

asm.js link error: As a temporary limitation, modules cannot be linked more than once.
This limitation should be removed in a future release. To work around this, compile a second module (e.g., using the Function constructor).

I haven't been able to find any documentation on this workaround. Does anyone have a working example?

Not my code, but this suffers from the same issue: http://jsperf.com/simplex-noise-comparison-asm View the issue in the console using FireFox.

Upvotes: 1

Views: 175

Answers (1)

Syntax
Syntax

Reputation: 2103

I was able to solve this myself. Here's a JSFiddle link for anyone who has the same issue: http://jsfiddle.net/QLtMB/

// Store template as actual function, do not use real pragma to avoid compile
var asmTemplate = function MyAsmModule( stdlib, foreign, heap ) {
   "asm template";

   var HEAP = new stdlib.Uint8Array(heap);
   var _sqrt = stdlib.Math.sqrt;
   var _sin = stdlib.Math.sin;
   var _cos = stdlib.Math.cos;


   function fastSqr( x ) {
      x = +x;
      return +(x*x);
   }

   function fastSqrt( x ) {
      x = +x;
      return +_sqrt( x );
   }

   function fastSin( x ) {
      x = +x;
      return +_sin( x );
   }

   function fastCos( x ) {
      x = +x;
      return +_cos( x );
   }

   function fastTest( x ) {
      x = +x;
      return +fastSqr( 2.17 * (+fastSqrt( 0.75 * +fastSin( x ) + 0.25 * +fastCos( x ) )) );
   }

   return { sqrt: fastSqrt, sin: fastSin, cos: fastCos, test: fastTest };
}

// Generate source string once, replace with real pragma.
asmTemplate = asmTemplate.toString().replace('asm template', 'use asm');

function createASM(buffer) {
    window.asmBufferExport = buffer;
    return Function(asmTemplate + "\nreturn MyAsmModule( Function( 'return this;' )(), null, asmBufferExport.buffer );")();
}

var Asm = createASM(new Uint8Array(4 * 1024));
var Asm2 = createASM(new Uint8Array(4 * 1024));

As a bonus, this will round your heap size up to asm.js standards:

    var size = <actual size>;
    // Round up to multiple of 4096
    var remainder = size % 4096;
    size = remainder ? size + 4096 - remainder : size;
    // Round up to the nearest power of 2
    size--;
    size |= size >> 1;  // handle  2 bit numbers
    size |= size >> 2;  // handle  4 bit numbers
    size |= size >> 4;  // handle  8 bit numbers
    size |= size >> 8;  // handle 16 bit numbers
    size |= size >> 16; // handle 32 bit numbers
    size++;

Resources:

Upvotes: 1

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