SqueakJS named primitives in the interpreter module

For named primitives, we can load and run a primitive function from a specific
module, as in the case of <primitive: 'primitiveFileSize' module: 'FilePlugin'>.

We can also load a primitive with module name unspecified, as in the case of
<primitive: 'primitiveScreenDepth'>. In that case we load and run the function
from the main interpreter module.

I want to implement the anonymous named primitive #primitiveUtcWithOffset in
SqueakJS, but I am a total JavaScript noob so I am looking for an example of
some other anonymous named primitive to use as a pattern.

At first glance, I do not see any anonymous named primitives implemented in vm.js,

so I want to ask - does the basic functionality of looking up and executing e.g.
#primitiveScreenDepth from the <primitive: 'primitiveScreenDepth'> pragma work?

> PS: makeStArray: might prove useful

You have correctly anticipated my next newbie question ;-)

I sent a git pull request for the new primitive, so hopefully you can
review it and include it in SqueakJS if it is not too horrible.

To my considerable surprise, DateAndTime>>now seems to be 70 times faster
on SqueakJS when using this primitive along with the enhancements in the
UTCDateAndTime repository.

I am inexperienced with JavaScript and Git, so in case any of this did not
get through, the proposed new function in Squeak.Primitives is:

    primitiveUtcWithOffset: function(argCount) {
        var d = new Date();
        var posixMicroseconds = this.pos53BitIntFor(d.getTime() * 1000);
        var offset = -60 * d.getTimezoneOffset();
        if (argCount > 0) {
            // either an Array or a DateAndTime in new UTC format with two ivars
            var stWordIndexableObject = this.vm.stackValue(0);
            stWordIndexableObject.pointers[0] = posixMicroseconds;
            stWordIndexableObject.pointers[1] = offset;
            this.popNandPushIfOK(argCount + 1, stWordIndexableObject);
            return true;
        }
        var timeAndOffset = [
            posixMicroseconds,
            offset,
        ];
        this.popNandPushIfOK(argCount + 1, this.makeStArray(timeAndOffset));
        return true;
    },

Sorry to reply to my own post, but I need to retract this. The profiler
shows that a big portion of the time is spent in

    LargePositiveInteger(Integer)>>digitDiv:neg:

I mistakenly assumed that primDigitDevNegative was not implemented for
the LargeIntegers module, but that is wrong, I see now that function
primDigitDivNegative() is implemented in the translated plugins. So maybe
it is not an efficient implementation when translated to JavaScript?

What is the range of your LargeIntegers? SqueakJS does not implement most of prims 30-37,

whereas the C VM at least does so with up to 64 bits IIRC?

https://github.com/bertfreudenberg/SqueakJS/blob/master/vm.js#L4301

This is just laziness on my part (since the fallback + plugin works), there's no good reason not to implement a fast path for these if the numbers fall within the 53 bit range JS can handle directly. We do have the code for 31 bit SmallInts, so this should be relatively simple.