Revision a121721f975fc4105ed24ebd0ad1020d08d07a38 authored by Shuhei Kadowaki on 01 November 2021, 10:49:07 UTC, committed by GitHub on 01 November 2021, 10:49:07 UTC
* inference: form `PartialStruct` for extra type information propagation This commit forms `PartialStruct` whenever there is any type-level refinement available about a field, even if it's not "constant" information. In Julia "definitions" are allowed to be abstract whereas "usages" (i.e. callsites) are often concrete. The basic idea is to allow inference to make more use of such precise callsite type information by encoding it as `PartialStruct`. This may increase optimization possibilities of "unidiomatic" Julia code, which may contain poorly-typed definitions, like this very contrived example: ```julia struct Problem n; s; c; t end function main(args...) prob = Problem(args...) s = 0 for i in 1:prob.n m = mod(i, 3) s += m == 0 ? sin(prob.s) : m == 1 ? cos(prob.c) : tan(prob.t) end return prob, s end main(10000, 1, 2, 3) ``` One of the obvious limitation is that this extra type information can be propagated inter-procedurally only as a const-propagation. I'm not sure this kind of "just a type-level" refinement can often make constant-prop' successful (i.e. shape-up a method body and allow it to be inlined, encoding the extra type information into the generated code), thus I didn't not modify any part of const-prop' heuristics. So the improvements from this change might not be very useful for general inter-procedural analysis currently, but they should definitely improve the accuracy of local analysis and very simple inter-procedural analysis.
1 parent 6c274ed
expr.jl
# This file is a part of Julia. License is MIT: https://julialang.org/license
## symbols ##
"""
gensym([tag])
Generates a symbol which will not conflict with other variable names.
"""
gensym() = ccall(:jl_gensym, Ref{Symbol}, ())
gensym(s::String) = ccall(:jl_tagged_gensym, Ref{Symbol}, (Ptr{UInt8}, Csize_t), s, sizeof(s))
gensym(ss::String...) = map(gensym, ss)
gensym(s::Symbol) = ccall(:jl_tagged_gensym, Ref{Symbol}, (Ptr{UInt8}, Csize_t), s, -1 % Csize_t)
"""
@gensym
Generates a gensym symbol for a variable. For example, `@gensym x y` is transformed into
`x = gensym("x"); y = gensym("y")`.
"""
macro gensym(names...)
blk = Expr(:block)
for name in names
push!(blk.args, :($(esc(name)) = gensym($(string(name)))))
end
push!(blk.args, :nothing)
return blk
end
## expressions ##
isexpr(@nospecialize(ex), head::Symbol) = isa(ex, Expr) && ex.head === head
isexpr(@nospecialize(ex), head::Symbol, n::Int) = isa(ex, Expr) && ex.head === head && length(ex.args) == n
copy(e::Expr) = exprarray(e.head, copy_exprargs(e.args))
# copy parts of an AST that the compiler mutates
function copy_exprs(@nospecialize(x))
if isa(x, Expr)
return copy(x)
elseif isa(x, PhiNode)
values = x.values
nvalues = length(values)
new_values = Vector{Any}(undef, nvalues)
@inbounds for i = 1:nvalues
isassigned(values, i) || continue
new_values[i] = copy_exprs(values[i])
end
return PhiNode(copy(x.edges), new_values)
elseif isa(x, PhiCNode)
values = x.values
nvalues = length(values)
new_values = Vector{Any}(undef, nvalues)
@inbounds for i = 1:nvalues
isassigned(values, i) || continue
new_values[i] = copy_exprs(values[i])
end
return PhiCNode(new_values)
end
return x
end
copy_exprargs(x::Array{Any,1}) = Any[copy_exprs(@inbounds x[i]) for i in 1:length(x)]
@eval exprarray(head::Symbol, arg::Array{Any,1}) = $(Expr(:new, :Expr, :head, :arg))
# create copies of the CodeInfo definition, and any mutable fields
function copy(c::CodeInfo)
cnew = ccall(:jl_copy_code_info, Ref{CodeInfo}, (Any,), c)
cnew.code = copy_exprargs(cnew.code)
cnew.slotnames = copy(cnew.slotnames)
cnew.slotflags = copy(cnew.slotflags)
cnew.codelocs = copy(cnew.codelocs)
cnew.linetable = copy(cnew.linetable::Union{Vector{Any},Vector{Core.LineInfoNode}})
cnew.ssaflags = copy(cnew.ssaflags)
cnew.edges = cnew.edges === nothing ? nothing : copy(cnew.edges::Vector)
ssavaluetypes = cnew.ssavaluetypes
ssavaluetypes isa Vector{Any} && (cnew.ssavaluetypes = copy(ssavaluetypes))
return cnew
end
==(x::Expr, y::Expr) = x.head === y.head && isequal(x.args, y.args)
==(x::QuoteNode, y::QuoteNode) = isequal(x.value, y.value)
==(stmt1::Core.PhiNode, stmt2::Core.PhiNode) = stmt1.edges == stmt2.edges && stmt1.values == stmt2.values
"""
macroexpand(m::Module, x; recursive=true)
Take the expression `x` and return an equivalent expression with all macros removed (expanded)
for executing in module `m`.
The `recursive` keyword controls whether deeper levels of nested macros are also expanded.
This is demonstrated in the example below:
```julia-repl
julia> module M
macro m1()
42
end
macro m2()
:(@m1())
end
end
M
julia> macroexpand(M, :(@m2()), recursive=true)
42
julia> macroexpand(M, :(@m2()), recursive=false)
:(#= REPL[16]:6 =# M.@m1)
```
"""
function macroexpand(m::Module, @nospecialize(x); recursive=true)
if recursive
ccall(:jl_macroexpand, Any, (Any, Any), x, m)
else
ccall(:jl_macroexpand1, Any, (Any, Any), x, m)
end
end
"""
@macroexpand
Return equivalent expression with all macros removed (expanded).
There are differences between `@macroexpand` and [`macroexpand`](@ref).
* While [`macroexpand`](@ref) takes a keyword argument `recursive`, `@macroexpand`
is always recursive. For a non recursive macro version, see [`@macroexpand1`](@ref).
* While [`macroexpand`](@ref) has an explicit `module` argument, `@macroexpand` always
expands with respect to the module in which it is called.
This is best seen in the following example:
```julia-repl
julia> module M
macro m()
1
end
function f()
(@macroexpand(@m),
macroexpand(M, :(@m)),
macroexpand(Main, :(@m))
)
end
end
M
julia> macro m()
2
end
@m (macro with 1 method)
julia> M.f()
(1, 1, 2)
```
With `@macroexpand` the expression expands where `@macroexpand` appears in the code (module `M` in the example).
With `macroexpand` the expression expands in the module given as the first argument.
"""
macro macroexpand(code)
return :(macroexpand($__module__, $(QuoteNode(code)), recursive=true))
end
"""
@macroexpand1
Non recursive version of [`@macroexpand`](@ref).
"""
macro macroexpand1(code)
return :(macroexpand($__module__, $(QuoteNode(code)), recursive=false))
end
## misc syntax ##
"""
Core.eval(m::Module, expr)
Evaluate an expression in the given module and return the result.
"""
Core.eval
"""
@inline
Give a hint to the compiler that this function is worth inlining.
Small functions typically do not need the `@inline` annotation,
as the compiler does it automatically. By using `@inline` on bigger functions,
an extra nudge can be given to the compiler to inline it.
`@inline` can be applied immediately before the definition or in its function body.
```julia
# annotate long-form definition
@inline function longdef(x)
...
end
# annotate short-form definition
@inline shortdef(x) = ...
# annotate anonymous function that a `do` block creates
f() do
@inline
...
end
```
!!! compat "Julia 1.8"
The usage within a function body requires at least Julia 1.8.
---
@inline block
Give a hint to the compiler that calls within `block` are worth inlining.
```julia
# The compiler will try to inline `f`
@inline f(...)
# The compiler will try to inline `f`, `g` and `+`
@inline f(...) + g(...)
```
!!! note
A callsite annotation always has the precedence over the annotation applied to the
definition of the called function:
```julia
@noinline function explicit_noinline(args...)
# body
end
let
@inline explicit_noinline(args...) # will be inlined
end
```
!!! note
When there are nested callsite annotations, the innermost annotation has the precedence:
```julia
@noinline let a0, b0 = ...
a = @inline f(a0) # the compiler will try to inline this call
b = f(b0) # the compiler will NOT try to inline this call
return a, b
end
```
!!! warning
Although a callsite annotation will try to force inlining in regardless of the cost model,
there are still chances it can't succeed in it. Especially, recursive calls can not be
inlined even if they are annotated as `@inline`d.
!!! compat "Julia 1.8"
The callsite annotation requires at least Julia 1.8.
"""
macro inline(x)
return annotate_meta_def_or_block(x, :inline)
end
"""
@noinline
Give a hint to the compiler that it should not inline a function.
Small functions are typically inlined automatically.
By using `@noinline` on small functions, auto-inlining can be
prevented.
`@noinline` can be applied immediately before the definition or in its function body.
```julia
# annotate long-form definition
@noinline function longdef(x)
...
end
# annotate short-form definition
@noinline shortdef(x) = ...
# annotate anonymous function that a `do` block creates
f() do
@noinline
...
end
```
!!! compat "Julia 1.8"
The usage within a function body requires at least Julia 1.8.
---
@noinline block
Give a hint to the compiler that it should not inline the calls within `block`.
```julia
# The compiler will try to not inline `f`
@noinline f(...)
# The compiler will try to not inline `f`, `g` and `+`
@noinline f(...) + g(...)
```
!!! note
A callsite annotation always has the precedence over the annotation applied to the
definition of the called function:
```julia
@inline function explicit_inline(args...)
# body
end
let
@noinline explicit_inline(args...) # will not be inlined
end
```
!!! note
When there are nested callsite annotations, the innermost annotation has the precedence:
```julia
@inline let a0, b0 = ...
a = @noinline f(a0) # the compiler will NOT try to inline this call
b = f(b0) # the compiler will try to inline this call
return a, b
end
```
!!! compat "Julia 1.8"
The callsite annotation requires at least Julia 1.8.
---
!!! note
If the function is trivial (for example returning a constant) it might get inlined anyway.
"""
macro noinline(x)
return annotate_meta_def_or_block(x, :noinline)
end
"""
@pure ex
@pure(ex)
`@pure` gives the compiler a hint for the definition of a pure function,
helping for type inference.
This macro is intended for internal compiler use and may be subject to changes.
"""
macro pure(ex)
esc(isa(ex, Expr) ? pushmeta!(ex, :pure) : ex)
end
"""
@constprop setting ex
@constprop(setting, ex)
`@constprop` controls the mode of interprocedural constant propagation for the
annotated function. Two `setting`s are supported:
- `@constprop :aggressive ex`: apply constant propagation aggressively.
For a method where the return type depends on the value of the arguments,
this can yield improved inference results at the cost of additional compile time.
- `@constprop :none ex`: disable constant propagation. This can reduce compile
times for functions that Julia might otherwise deem worthy of constant-propagation.
Common cases are for functions with `Bool`- or `Symbol`-valued arguments or keyword arguments.
"""
macro constprop(setting, ex)
if isa(setting, QuoteNode)
setting = setting.value
end
setting === :aggressive && return esc(isa(ex, Expr) ? pushmeta!(ex, :aggressive_constprop) : ex)
setting === :none && return esc(isa(ex, Expr) ? pushmeta!(ex, :no_constprop) : ex)
throw(ArgumentError("@constprop $setting not supported"))
end
"""
@propagate_inbounds
Tells the compiler to inline a function while retaining the caller's inbounds context.
"""
macro propagate_inbounds(ex)
if isa(ex, Expr)
pushmeta!(ex, :inline)
pushmeta!(ex, :propagate_inbounds)
end
esc(ex)
end
"""
@polly
Tells the compiler to apply the polyhedral optimizer Polly to a function.
"""
macro polly(ex)
esc(isa(ex, Expr) ? pushmeta!(ex, :polly) : ex)
end
## some macro utilities ##
unwrap_macrocalls(@nospecialize(x)) = x
function unwrap_macrocalls(ex::Expr)
inner = ex
while inner.head === :macrocall
inner = inner.args[end]::Expr
end
return inner
end
function pushmeta!(ex::Expr, sym::Symbol, args::Any...)
if isempty(args)
tag = sym
else
tag = Expr(sym, args...)::Expr
end
inner = unwrap_macrocalls(ex)
idx, exargs = findmeta(inner)
if idx != 0
push!(exargs[idx].args, tag)
else
body = inner.args[2]::Expr
pushfirst!(body.args, Expr(:meta, tag))
end
ex
end
popmeta!(body, sym) = _getmeta(body, sym, true)
peekmeta(body, sym) = _getmeta(body, sym, false)
function _getmeta(body::Expr, sym::Symbol, delete::Bool)
body.head === :block || return false, []
_getmeta(body.args, sym, delete)
end
_getmeta(arg, sym, delete::Bool) = (false, [])
function _getmeta(body::Array{Any,1}, sym::Symbol, delete::Bool)
idx, blockargs = findmeta_block(body, args -> findmetaarg(args,sym)!=0)
if idx == 0
return false, []
end
metaargs = blockargs[idx].args
i = findmetaarg(blockargs[idx].args, sym)
if i == 0
return false, []
end
ret = isa(metaargs[i], Expr) ? (metaargs[i]::Expr).args : []
if delete
deleteat!(metaargs, i)
isempty(metaargs) && deleteat!(blockargs, idx)
end
true, ret
end
# Find index of `sym` in a meta expression argument list, or 0.
function findmetaarg(metaargs, sym)
for i = 1:length(metaargs)
arg = metaargs[i]
if (isa(arg, Symbol) && (arg::Symbol) == sym) ||
(isa(arg, Expr) && (arg::Expr).head == sym)
return i
end
end
return 0
end
function annotate_meta_def_or_block(@nospecialize(ex), meta::Symbol)
inner = unwrap_macrocalls(ex)
if is_function_def(inner)
# annotation on a definition
return esc(pushmeta!(ex, meta))
else
# annotation on a block
return Expr(:block,
Expr(meta, true),
Expr(:local, Expr(:(=), :val, esc(ex))),
Expr(meta, false),
:val)
end
end
function is_short_function_def(@nospecialize(ex))
isexpr(ex, :(=)) || return false
while length(ex.args) >= 1 && isa(ex.args[1], Expr)
(ex.args[1].head === :call) && return true
(ex.args[1].head === :where || ex.args[1].head === :(::)) || return false
ex = ex.args[1]
end
return false
end
is_function_def(@nospecialize(ex)) =
return isexpr(ex, :function) || is_short_function_def(ex) || isexpr(ex, :->)
function findmeta(ex::Expr)
if is_function_def(ex)
body = ex.args[2]::Expr
body.head === :block || error(body, " is not a block expression")
return findmeta_block(ex.args)
end
error(ex, " is not a function expression")
end
findmeta(ex::Array{Any,1}) = findmeta_block(ex)
function findmeta_block(exargs, argsmatch=args->true)
for i = 1:length(exargs)
a = exargs[i]
if isa(a, Expr)
if a.head === :meta && argsmatch(a.args)
return i, exargs
elseif a.head === :block
idx, exa = findmeta_block(a.args, argsmatch)
if idx != 0
return idx, exa
end
end
end
end
return 0, []
end
remove_linenums!(ex) = ex
function remove_linenums!(ex::Expr)
if ex.head === :block || ex.head === :quote
# remove line number expressions from metadata (not argument literal or inert) position
filter!(ex.args) do x
isa(x, Expr) && x.head === :line && return false
isa(x, LineNumberNode) && return false
return true
end
end
for subex in ex.args
subex isa Expr && remove_linenums!(subex)
end
return ex
end
function remove_linenums!(src::CodeInfo)
src.codelocs .= 0
length(src.linetable) > 1 && resize!(src.linetable, 1)
return src
end
macro generated()
return Expr(:generated)
end
"""
@generated f
@generated(f)
`@generated` is used to annotate a function which will be generated.
In the body of the generated function, only types of arguments can be read
(not the values). The function returns a quoted expression evaluated when the
function is called. The `@generated` macro should not be used on functions mutating
the global scope or depending on mutable elements.
See [Metaprogramming](@ref) for further details.
## Example:
```jldoctest
julia> @generated function bar(x)
if x <: Integer
return :(x ^ 2)
else
return :(x)
end
end
bar (generic function with 1 method)
julia> bar(4)
16
julia> bar("baz")
"baz"
```
"""
macro generated(f)
if isa(f, Expr) && (f.head === :function || is_short_function_def(f))
body = f.args[2]
lno = body.args[1]
return Expr(:escape,
Expr(f.head, f.args[1],
Expr(:block,
lno,
Expr(:if, Expr(:generated),
# https://github.com/JuliaLang/julia/issues/25678
Expr(:block,
:(local tmp = $body),
:(if tmp isa Core.CodeInfo; return tmp; else tmp; end)),
Expr(:block,
Expr(:meta, :generated_only),
Expr(:return, nothing))))))
else
error("invalid syntax; @generated must be used with a function definition")
end
end
"""
@atomic var
@atomic order ex
Mark `var` or `ex` as being performed atomically, if `ex` is a supported expression.
@atomic a.b.x = new
@atomic a.b.x += addend
@atomic :acquire_release a.b.x = new
@atomic :acquire_release a.b.x += addend
Perform the store operation expressed on the right atomically and return the
new value.
With `=`, this operation translates to a `setproperty!(a.b, :x, new)` call.
With any operator also, this operation translates to a `modifyproperty!(a.b,
:x, +, addend)[2]` call.
@atomic a.b.x max arg2
@atomic a.b.x + arg2
@atomic max(a.b.x, arg2)
@atomic :acquire_release max(a.b.x, arg2)
@atomic :acquire_release a.b.x + arg2
@atomic :acquire_release a.b.x max arg2
Perform the binary operation expressed on the right atomically. Store the
result into the field in the first argument and return the values `(old, new)`.
This operation translates to a `modifyproperty!(a.b, :x, func, arg2)` call.
See [Per-field atomics](@ref man-atomics) section in the manual for more details.
```jldoctest
julia> mutable struct Atomic{T}; @atomic x::T; end
julia> a = Atomic(1)
Atomic{Int64}(1)
julia> @atomic a.x # fetch field x of a, with sequential consistency
1
julia> @atomic :sequentially_consistent a.x = 2 # set field x of a, with sequential consistency
2
julia> @atomic a.x += 1 # increment field x of a, with sequential consistency
3
julia> @atomic a.x + 1 # increment field x of a, with sequential consistency
3 => 4
julia> @atomic a.x # fetch field x of a, with sequential consistency
4
julia> @atomic max(a.x, 10) # change field x of a to the max value, with sequential consistency
4 => 10
julia> @atomic a.x max 5 # again change field x of a to the max value, with sequential consistency
10 => 10
```
!!! compat "Julia 1.7"
This functionality requires at least Julia 1.7.
"""
macro atomic(ex)
if !isa(ex, Symbol) && !is_expr(ex, :(::))
return make_atomic(QuoteNode(:sequentially_consistent), ex)
end
return esc(Expr(:atomic, ex))
end
macro atomic(order, ex)
order isa QuoteNode || (order = esc(order))
return make_atomic(order, ex)
end
macro atomic(a1, op, a2)
return make_atomic(QuoteNode(:sequentially_consistent), a1, op, a2)
end
macro atomic(order, a1, op, a2)
order isa QuoteNode || (order = esc(order))
return make_atomic(order, a1, op, a2)
end
function make_atomic(order, ex)
@nospecialize
if ex isa Expr
if isexpr(ex, :., 2)
l, r = esc(ex.args[1]), esc(ex.args[2])
return :(getproperty($l, $r, $order))
elseif isexpr(ex, :call, 3)
return make_atomic(order, ex.args[2], ex.args[1], ex.args[3])
elseif ex.head === :(=)
l, r = ex.args[1], esc(ex.args[2])
if is_expr(l, :., 2)
ll, lr = esc(l.args[1]), esc(l.args[2])
return :(setproperty!($ll, $lr, $r, $order))
end
end
if length(ex.args) == 2
if ex.head === :(+=)
op = :+
elseif ex.head === :(-=)
op = :-
elseif @isdefined string
shead = string(ex.head)
if endswith(shead, '=')
op = Symbol(shead[1:prevind(shead, end)])
end
end
if @isdefined(op)
return Expr(:ref, make_atomic(order, ex.args[1], op, ex.args[2]), 2)
end
end
end
error("could not parse @atomic expression $ex")
end
function make_atomic(order, a1, op, a2)
@nospecialize
is_expr(a1, :., 2) || error("@atomic modify expression missing field access")
a1l, a1r, op, a2 = esc(a1.args[1]), esc(a1.args[2]), esc(op), esc(a2)
return :(modifyproperty!($a1l, $a1r, $op, $a2, $order))
end
"""
@atomicswap a.b.x = new
@atomicswap :sequentially_consistent a.b.x = new
Stores `new` into `a.b.x` and returns the old value of `a.b.x`.
This operation translates to a `swapproperty!(a.b, :x, new)` call.
See [Per-field atomics](@ref man-atomics) section in the manual for more details.
```jldoctest
julia> mutable struct Atomic{T}; @atomic x::T; end
julia> a = Atomic(1)
Atomic{Int64}(1)
julia> @atomicswap a.x = 2+2 # replace field x of a with 4, with sequential consistency
1
julia> @atomic a.x # fetch field x of a, with sequential consistency
4
```
!!! compat "Julia 1.7"
This functionality requires at least Julia 1.7.
"""
macro atomicswap(order, ex)
order isa QuoteNode || (order = esc(order))
return make_atomicswap(order, ex)
end
macro atomicswap(ex)
return make_atomicswap(QuoteNode(:sequentially_consistent), ex)
end
function make_atomicswap(order, ex)
@nospecialize
is_expr(ex, :(=), 2) || error("@atomicswap expression missing assignment")
l, val = ex.args[1], esc(ex.args[2])
is_expr(l, :., 2) || error("@atomicswap expression missing field access")
ll, lr = esc(l.args[1]), esc(l.args[2])
return :(swapproperty!($ll, $lr, $val, $order))
end
"""
@atomicreplace a.b.x expected => desired
@atomicreplace :sequentially_consistent a.b.x expected => desired
@atomicreplace :sequentially_consistent :monotonic a.b.x expected => desired
Perform the conditional replacement expressed by the pair atomically, returning
the values `(old, success::Bool)`. Where `success` indicates whether the
replacement was completed.
This operation translates to a `replaceproperty!(a.b, :x, expected, desired)` call.
See [Per-field atomics](@ref man-atomics) section in the manual for more details.
```jldoctest
julia> mutable struct Atomic{T}; @atomic x::T; end
julia> a = Atomic(1)
Atomic{Int64}(1)
julia> @atomicreplace a.x 1 => 2 # replace field x of a with 2 if it was 1, with sequential consistency
(old = 1, success = true)
julia> @atomic a.x # fetch field x of a, with sequential consistency
2
julia> @atomicreplace a.x 1 => 2 # replace field x of a with 2 if it was 1, with sequential consistency
(old = 2, success = false)
julia> xchg = 2 => 0; # replace field x of a with 0 if it was 1, with sequential consistency
julia> @atomicreplace a.x xchg
(old = 2, success = true)
julia> @atomic a.x # fetch field x of a, with sequential consistency
0
```
!!! compat "Julia 1.7"
This functionality requires at least Julia 1.7.
"""
macro atomicreplace(success_order, fail_order, ex, old_new)
fail_order isa QuoteNode || (fail_order = esc(fail_order))
success_order isa QuoteNode || (success_order = esc(success_order))
return make_atomicreplace(success_order, fail_order, ex, old_new)
end
macro atomicreplace(order, ex, old_new)
order isa QuoteNode || (order = esc(order))
return make_atomicreplace(order, order, ex, old_new)
end
macro atomicreplace(ex, old_new)
return make_atomicreplace(QuoteNode(:sequentially_consistent), QuoteNode(:sequentially_consistent), ex, old_new)
end
function make_atomicreplace(success_order, fail_order, ex, old_new)
@nospecialize
is_expr(ex, :., 2) || error("@atomicreplace expression missing field access")
ll, lr = esc(ex.args[1]), esc(ex.args[2])
if is_expr(old_new, :call, 3) && old_new.args[1] === :(=>)
exp, rep = esc(old_new.args[2]), esc(old_new.args[3])
return :(replaceproperty!($ll, $lr, $exp, $rep, $success_order, $fail_order))
else
old_new = esc(old_new)
return :(replaceproperty!($ll, $lr, $old_new::Pair..., $success_order, $fail_order))
end
end
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...