tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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litmus2.js (1710B)


      1 // Mutually recursive functions implement a multi-entry loop using indirect tail
      2 // calls.  The functions do not have the same signatures, so if all arguments
      3 // are stack arguments then these use different amounts of stack space.
      4 //
      5 // The variable ballast is intended to test that we handle various combinations
      6 // of stack and register arguments properly.
      7 
      8 for ( let ballast=1; ballast < TailCallBallast; ballast++ ) {
      9    let vals = iota(ballast,1);
     10    let ps = vals.map(_ => 'i32').join(' ')
     11    let es = vals.map(i => `(local.get ${i})`).join(' ')
     12    let sum = vals.reduceRight((p,c) => `(i32.add (local.get ${c}) ${p})`, `(i32.const 0)`)
     13    let sumv = vals.reduce((p,c) => p+c);
     14    let text = `
     15 (module
     16  (table 2 2 funcref)
     17  (elem (i32.const 0) $even $odd)
     18  (type $t (func (param i32 ${ps}) (result i32)))
     19  (type $q (func (param i32 ${ps} i32) (result i32)))
     20 
     21  (func $odd (export "odd") (param $n i32) (param ${ps}) (param $dummy i32) (result i32)
     22    (if (result i32) (i32.eqz (local.get $n))
     23        (then (return (i32.or (i32.shl ${sum} (i32.const 1)) (i32.const 0))))
     24        (else (return_call_indirect (type $t) (i32.sub (local.get $n) (i32.const 1)) ${es} (i32.const 0)))))
     25 
     26  (func $even (export "even") (param $n i32) (param ${ps}) (result i32)
     27    (if (result i32) (i32.eqz (local.get $n))
     28        (then (return (i32.or (i32.shl ${sum} (i32.const 1)) (i32.const 1))))
     29        (else (return_call_indirect (type $q) (i32.sub (local.get $n) (i32.const 1)) ${es} (i32.const 33) (i32.const 1))))))`
     30 
     31    let ins = wasmEvalText(text);
     32    assertEq(ins.exports.even(TailCallIterations, ...vals), (sumv*2) + 1);
     33    assertEq(ins.exports.odd(TailCallIterations, ...vals, 33), (sumv*2) + 0);
     34 }