Simplified, Slow version that causes deoptimization

slowdown.js

function pcg_setseq_128_srandom_r()
{
	//const state = new Uint32Array([0,0,0,0,0,0,0,0]);
	const state = [0,0,0,0,0,0,0,0];
	const b = [ 0x7F2D, 0x4C95, 0xF42D, 0x5851  ];
	const c = [ 0x7F2D, 0x4C95, 0xF42D, 0x5851  ];

	const rng = {
		state: new Uint32Array([0,0,0,0,0,0,0,0]),
		inc: [ 0x7F2D, 0x4C95, 0xF42D, 0x5851 ],
		get : null // will be the step and output function pair
	}	

	function pcg_setseq_64_xsh_rr_32_r(  )
	{
		//const a = rng.state;
		var a = state;
		//var a = rng.state;//new Uint32Array([0,0,0,0,0,0,0,0]);

		/* some work on 'rng.state' */
		var over = 0;
		over = ( (a[0]*b[0])+c[0] );
		a[0] = over & 0xFFFF; over >>>= 16;
		over += ( (a[1]*b[1])+c[1] );
		const s1 = a[1] = over & 0xFFFF; over >>>= 16;
		over += ( (a[2]*b[2])+c[2] );
		const s2 = a[2] = over & 0xFFFF; over >>>= 16;
		over += ( (a[3]*b[3])+c[3] );
		const s3 = a[3] = over & 0xFFFF; over >>>= 16;

		return over;
	}
	rng.get = pcg_setseq_64_xsh_rr_32_r;

	rng.get();

	return rng;

}	        

var n, m;

var testRng = pcg_setseq_128_srandom_r(  )

console.log( testRng );

var start = Date.now();
for( n = 0; n < 10000; n++ )
	for( m = 0; m < 10000; m++ ) {
       		testRng.get();
	}

console.log( "Done in ", Date.now() - start, "/ms", (m*n)/(Date.now()-start), ((m*n)/(Date.now()-start)) * 32 );