Math.minmax

[Boris Zbarsky]

On 6/29/17 1:49 AM, T.J. Crowder wrote:
> I was going to make that very point, backed by a jsPerf, but the jsPerf
> doesn't back it up: https://jsperf.com/two-calls-vs-one-returning-array
> It says the minmax is faster on a 10-entry array (it reports the
> separate calls as 46-48% slower on V8 and SpiderMonkey).

See https://jsperf.com/two-calls-vs-one-no-destructuring/1 which is the 
same as the above-linked testcase but doesn't do destructuring of an 
array into an arglist and the collapsing of an arglist into an array for 
every call.  In that one the two-call version is in fact faster.

That is, the cost of allocating and filling the two-element return value 
array is much smaller than the cost of allocating and filling the 
20-element array.  Since the two-call testcase in 
https://jsperf.com/two-calls-vs-one-returning-array does the latter 
twice, it ends up slower than the version that only does it once.

-Boris