Use unchecked-*-int functions for real 32-bit math

Description

Currently the unchecked-* functions and macros simply alias the primitive js operators. It would be nice if the unchecked-*-int family of functions and macros implemented C/Java-like signed int operations with silent overflows (just like in Clojure) using asm.js coersion idioms. This should also allow us to share such code between clojure and clojurescript without worrying about their different numerics.

A use case is that porting hash algorithms from java to clojurescript is trickier and more verbose than it needs to be.

Environment

r2173

Activity

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David Nolen
May 9, 2014, 10:43 AM

This sounds interesting, would like to see more thoughts on approach, benchmarks etc.

David Nolen
December 2, 2014, 10:46 PM

Bump, this enhancements sound simple & fine.

Francis Avila
December 3, 2014, 6:26 AM

I'll have time to do this in about a week. The implementation is straightforward (basically use xor 0 everywhere). The goal is correctness, but I expect performance to be as good as or better than it is now on most platforms. I'm not sure if advanced mode will drop intermediate truncations or what impact this has on performance.

Some higher-level numeric analysis using the asm.js type system is possible but I doubt it's worth it.

Francis Avila
March 17, 2015, 4:14 AM

I completely forgot about this, sorry. I see you have scheduled it for the "next" release. Are you assigning it as well or will you still accept a patch?

David Nolen
March 17, 2015, 4:26 AM

Be my guest

Assignee

Francis Avila

Reporter

Francis Avila

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Approval

None

Patch

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Fix versions

Affects versions

Priority

Minor