[NewOptimizer] Make stmt_effect_free less aggressive #26948
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Keno
added
the
compiler:optimizer
vtjnash
reviewed
May 1, 2018
base/compiler/tfuncs.jl
Outdated
| (isa(a, DataType) && (isa(a.parameters[1], Type) || isa(a.parameters[1], TypeVar))) || return false | ||
| at = a.parameters[1] | ||
| # Check that the element type is compatible with the element we're assigning | ||
| (argtypes[3] ⊑ (isa(at, Type) ? at : at.lb)) || return false |
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So, iterate until we hit a type? Can they be circular?
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can't be circular, I think Jeff added a helper function to unwrap TypeVar
vtjnash
reviewed
May 1, 2018
| if isa(name, Const) | ||
| (isa(sv, Module) && isa(name.val, Symbol)) || return false | ||
| (isa(name.val, Symbol) || isa(name.val, Int)) || return false | ||
| return isdefined(sv, name.val) |
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only if immutable (or isdefined returns true)
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Is that true? Can you un-initialize a field of a mutable?
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Oh, right. I was thinking this was returning the value – not whether it's an error
base/compiler/tfuncs.jl
Outdated
| if isa(s, Union) | ||
| return getfield_nothrow(rewrap(s.a, s00), name, inbounds) && | ||
| getfield_nothrow(rewrap(s.b, s00), name, inbounds) | ||
| elseif isa(s, Conditional) |
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s can't be Conditional after widenconst
base/compiler/tfuncs.jl
Outdated
| s.abstract && return false | ||
| # If all fields are always initialized, and bounds check is disabled, we can assume | ||
| # we don't throw | ||
| (fieldcount(s) == s.ninitialized) && return true |
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may throw (isvatuple, or some NamedTuples)
Previously, the new optimizer used the pre-existing `effect_free` function to determine whether it is safe to remove an unreferenced statement. However, this function ignores many builtin's error cases, causing them to be removed when that is not legal to do (because that would potentially remove an exception that would otherwise be thrown). Start fixing this, by introducing a version of the function that is correct for a subset of intresting functions. We will likely need to expand this when we look at the benchmarks, but this should be correct for now.
yuyichao
added a commit
that referenced
this pull request
Sep 6, 2020
* Use the field index passed in in `lift_leaves`
The caller has already done all the computation including bound checking.
The `field` computed in this function is also affecting all the following iterations
which is almost certainly wrong.
* Remove unnecessary type check on `field` in `lift_leaves` since it is always `Int`
* Move a branch disabling `return nothing` higher up
* Remove some duplicated calculation on field index in `getfield_elim_pass!`
* Fix `try_compute_fieldidx` to return `nothing` for non-`Int` `Integer` field index.
This can cause `getfield_nothrow` to return incorrect result.
It also gives the caller worse type info about the return value.
* Teach `getfield_nothrow` that `isbits` field cannot be undefined and getfield on such field cannot throw.
This is already handled in `isdefined_tfunc`.
----
Ref #26948 (fa02d34)
Ref #27126 (9100329)
yuyichao
added a commit
that referenced
this pull request
Sep 6, 2020
* Use the field index passed in in `lift_leaves`
The caller has already done all the computation including bound checking.
The `field` computed in this function is also affecting all the following iterations
which is almost certainly wrong.
* Remove unnecessary type check on `field` in `lift_leaves` since it is always `Int`
* Move a branch disabling `return nothing` higher up
* Remove some duplicated calculation on field index in `getfield_elim_pass!`
* Fix `try_compute_fieldidx` to return `nothing` for non-`Int` `Integer` field index.
This can cause `getfield_nothrow` to return incorrect result.
It also gives the caller worse type info about the return value.
* Teach `getfield_nothrow` that `isbits` field cannot be undefined and getfield on such field cannot throw.
This is already handled in `isdefined_tfunc`.
----
Ref #26948 (fa02d34)
Ref #27126 (9100329)
yuyichao
added a commit
that referenced
this pull request
Sep 6, 2020
* Use the field index passed in in `lift_leaves`
The caller has already done all the computation including bound checking.
The `field` computed in this function is also affecting all the following iterations
which is almost certainly wrong.
* Remove unnecessary type check on `field` in `lift_leaves` since it is always `Int`
* Move a branch disabling `return nothing` higher up
* Remove some duplicated calculation on field index in `getfield_elim_pass!`
* Fix `try_compute_fieldidx` to return `nothing` for non-`Int` `Integer` field index.
This can cause `getfield_nothrow` to return incorrect result.
It also gives the caller worse type info about the return value.
* Teach `getfield_nothrow` that `isbits` field cannot be undefined and getfield on such field cannot throw.
This is already handled in `isdefined_tfunc`.
* Fix a few wrong use of `isbits` in dead branches
----
Ref #26948 (fa02d34)
Ref #27126 (9100329)
Keno
pushed a commit
that referenced
this pull request
Dec 30, 2020
* Use the field index passed in in `lift_leaves`
The caller has already done all the computation including bound checking.
The `field` computed in this function is also affecting all the following iterations
which is almost certainly wrong.
* Remove unnecessary type check on `field` in `lift_leaves` since it is always `Int`
* Move a branch disabling `return nothing` higher up
* Remove some duplicated calculation on field index in `getfield_elim_pass!`
* Fix `try_compute_fieldidx` to return `nothing` for non-`Int` `Integer` field index.
This can cause `getfield_nothrow` to return incorrect result.
It also gives the caller worse type info about the return value.
* Teach `getfield_nothrow` that `isbits` field cannot be undefined and getfield on such field cannot throw.
This is already handled in `isdefined_tfunc`.
* Fix a few wrong use of `isbits` in dead branches
----
Ref #26948 (fa02d34)
Ref #27126 (9100329)
ElOceanografo
pushed a commit
to ElOceanografo/julia
that referenced
this pull request
May 4, 2021
* Use the field index passed in in `lift_leaves`
The caller has already done all the computation including bound checking.
The `field` computed in this function is also affecting all the following iterations
which is almost certainly wrong.
* Remove unnecessary type check on `field` in `lift_leaves` since it is always `Int`
* Move a branch disabling `return nothing` higher up
* Remove some duplicated calculation on field index in `getfield_elim_pass!`
* Fix `try_compute_fieldidx` to return `nothing` for non-`Int` `Integer` field index.
This can cause `getfield_nothrow` to return incorrect result.
It also gives the caller worse type info about the return value.
* Teach `getfield_nothrow` that `isbits` field cannot be undefined and getfield on such field cannot throw.
This is already handled in `isdefined_tfunc`.
* Fix a few wrong use of `isbits` in dead branches
----
Ref JuliaLang#26948 (fa02d34)
Ref JuliaLang#27126 (9100329)
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Previously, the new optimizer used the pre-existing
effect_freefunctionto determine whether it is safe to remove an unreferenced statement. However,
this function ignores many builtin's error cases, causing them to be
removed when that is not legal to do (because that would potentially remove
an exception that would otherwise be thrown). Start fixing this, by
introducing a version of the function that is correct for a subset of
intresting functions. We will likely need to expand this when we look
at the benchmarks, but this should be correct for now.