Re^3: Pass an array reference or array indices to a subroutine?

May be my question should have been which one of these is faster: dereferencing an array or a scalar.

They're about the same; almost irrelevant in any real program.

Accessing a lexical is faster than accessing a global, though the speed difference there is also almost always irrelevant.

Comment on Re^3: Pass an array reference or array indices to a subroutine?

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Re^4: Pass an array reference or array indices to a subroutine? by ikegami (Patriarch) on Feb 24, 2011 at 22:13 UTC
They're about the same; almost irrelevant in any real program. I propose that they're exactly the same. `$ perl -MO=Concise,-exec -e'$$ref' 1 <0> enter 2 <;> nextstate(main 1 -e:1) v:{ 3 <$> gvsv(ref) s 4 <1> rv2sv vK/1 5 <@> leave[1 ref] vKP/REFC -e syntax OK $ perl -MO=Concise,-exec -e'@$ref' 1 <0> enter 2 <;> nextstate(main 1 -e:1) v:{ 3 <$> gvsv(ref) s 4 <1> rv2av[t1] vK/1 5 <@> leave[1 ref] vKP/REFC -e syntax OK` [download] The normal case of rv2sv boils down to a couple of checks plus `sv = SvRV(sv);` [download] The normal case of rv2av boils down to a couple of checks plus `sv = SvRV(sv);` [download] So any difference in performance is not intrinsic to the operation.	[reply] [d/l] [select]

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Re^4: Pass an array reference or array indices to a subroutine?
by ikegami (Patriarch) on Feb 24, 2011 at 22:13 UTC

They're about the same; almost irrelevant in any real program.

I propose that they're exactly the same.

$ perl -MO=Concise,-exec -e'$$ref'
1  <0> enter 
2  <;> nextstate(main 1 -e:1) v:{
3  <$> gvsv(*ref) s
4  <1> rv2sv vK/1
5  <@> leave[1 ref] vKP/REFC
-e syntax OK

$ perl -MO=Concise,-exec -e'@$ref'
1  <0> enter 
2  <;> nextstate(main 1 -e:1) v:{
3  <$> gvsv(*ref) s
4  <1> rv2av[t1] vK/1
5  <@> leave[1 ref] vKP/REFC
-e syntax OK
[download]

The normal case of rv2sv boils down to a couple of checks plus

sv = SvRV(sv);
[download]

The normal case of rv2av boils down to a couple of checks plus

sv = SvRV(sv);
[download]

So any difference in performance is not intrinsic to the operation.

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[select]