VM: Speed up chaining assign. - #1163
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schungx
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ImTheSquid
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Sep 13, 2026
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This PR speeds up chaining assignments such as
a[x] = something.Currently, the VM runs an assignment on a chain around 50% slower than the AST walker.
That is because it first calculates the resultant value, then pushes it into the
Scopeunder a dummy name, then it processes the operands, and finally it reads the value back from theScopeand puts it back onto the stack.This PR eliminates this entire process by changing the order of the stack pushes -- with the resultant value pushed first. The whole process now operates purely on the stack without touching the
Scope.Chain assignments now run at par with the AST walker, with the
primesbench reaching 1.0x speed.Another minor enhancement is the use of
Scope::push_entrywhich takes anImmutableStringwhich can be cloned from the strings interner. This avoids additional allocations of the same strings over and over again.