From 8a8325fb9d2cfaf7c208db0f7d676dcab9c4eba0 Mon Sep 17 00:00:00 2001 From: sterni Date: Wed, 25 Jan 2023 14:39:24 +0100 Subject: docs(tvix/eval): builtins.add is not equivalent to + While it is in the given example, i.e. for integer addition, to claim that they are equivalent is a bit misleading: builtins.add is less overloaded than +, i.e. builtins.add "foo" "bar" will fail whereas "foo" + "bar" performs string concatenation. Change-Id: Ib52d530d1ab289b367565b286f06a76dd518d4fb Reviewed-on: https://cl.tvl.fyi/c/depot/+/7929 Autosubmit: sterni Reviewed-by: flokli Tested-by: BuildkiteCI --- tvix/eval/docs/known-optimisation-potential.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tvix/eval/docs/known-optimisation-potential.md b/tvix/eval/docs/known-optimisation-potential.md index e3015fc44b8a..df13577de3ba 100644 --- a/tvix/eval/docs/known-optimisation-potential.md +++ b/tvix/eval/docs/known-optimisation-potential.md @@ -64,8 +64,8 @@ optimisations, but note the most important ones here. * Inline fully applied builtins with equivalent operators [medium] - Some `builtins` have equivalent operators, e.g. `builtins.add` - corresponds to the `+` operator, `builtins.hasAttr` to the `?` + Some `builtins` have equivalent operators, e.g. `builtins.sub` + corresponds to the `-` operator, `builtins.hasAttr` to the `?` operator etc. These operators additionally compile to a primitive VM opcode, so they should be just as cheap (if not cheaper) as a builtin application. @@ -73,7 +73,7 @@ optimisations, but note the most important ones here. In case the compiler encounters a fully applied builtin (i.e. no currying is occurring) and the `builtins` global is unshadowed, it could compile the equivalent operator bytecode instead: For - example, `builtins.add 20 22` would be compiled as `20 + 22`. + example, `builtins.sub 20 22` would be compiled as `20 - 22`. This would ensure that equivalent `builtins` can also benefit from special optimisations we may implement for certain operators (in the absence of currying). E.g. we could optimise access -- cgit 1.4.1