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Refactor the meaning of NewSSAValue in IncrementalCompact #45610

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Jun 10, 2022
Merged

Refactor the meaning of NewSSAValue in IncrementalCompact #45610

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116 changes: 76 additions & 40 deletions base/compiler/ssair/ir.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -153,8 +153,24 @@ struct OldSSAValue
id::Int
end

# SSA values that are in `new_new_nodes` of an `IncrementalCompact` and are to
# be actually inserted next time (they become `new_nodes` next time)
## TODO: This description currently omits the use of NewSSAValue during slot2ssa,
## which doesn't use IncrementalCompact, but does something similar and also uses
## NewSSAValue to refer to new_nodes. Ideally that use of NewSSAValue would go away
## during a refactor.
"""
struct NewSSAValue

`NewSSAValue`s occur in the context of IncrementalCompact. Their meaning depends
on where they appear:

1. In already-compacted nodes,
i. a `NewSSAValue` with positive `id` has the same meaning as a regular SSAValue.
ii. a `NewSSAValue` with negative `id` refers to post-compaction `new_node` node.

2. In non-compacted nodes,
i. a `NewSSAValue` with positive `id` refers to the index of an already-compacted instructions.
ii. a `NewSSAValue` with negative `id` has the same meaning as in compacted nodes.
"""
struct NewSSAValue
id::Int
end
Expand Down Expand Up @@ -618,38 +634,33 @@ struct TypesView{T}
end
types(ir::Union{IRCode, IncrementalCompact}) = TypesView(ir)

# TODO We can be a bit better about access here by using a pattern similar to InstructionStream
function getindex(compact::IncrementalCompact, idx::Int)
if idx < compact.result_idx
return compact.result[idx][:inst]
else
return compact.ir.stmts[idx][:inst]
end
end

function getindex(compact::IncrementalCompact, ssa::SSAValue)
@assert ssa.id < compact.result_idx
return compact.result[ssa.id][:inst]
return compact.result[ssa.id]
end

function getindex(compact::IncrementalCompact, ssa::OldSSAValue)
id = ssa.id
if id < compact.idx
new_idx = compact.ssa_rename[id]
return compact.result[new_idx][:inst]
return compact.result[new_idx]
elseif id <= length(compact.ir.stmts)
return compact.ir.stmts[id][:inst]
return compact.ir.stmts[id]
end
id -= length(compact.ir.stmts)
if id <= length(compact.ir.new_nodes)
return compact.ir.new_nodes.stmts[id][:inst]
return compact.ir.new_nodes.stmts[id]
end
id -= length(compact.ir.new_nodes)
return compact.pending_nodes.stmts[id][:inst]
return compact.pending_nodes.stmts[id]
end

function getindex(compact::IncrementalCompact, ssa::NewSSAValue)
return compact.new_new_nodes.stmts[ssa.id][:inst]
if ssa.id < 0
return compact.new_new_nodes.stmts[-ssa.id]
else
return compact[SSAValue(ssa.id)]
end
end

function block_for_inst(compact::IncrementalCompact, idx::SSAValue)
Expand All @@ -671,7 +682,12 @@ function block_for_inst(compact::IncrementalCompact, idx::OldSSAValue)
end

function block_for_inst(compact::IncrementalCompact, idx::NewSSAValue)
block_for_inst(compact, SSAValue(compact.new_new_nodes.info[idx.id].pos))
if idx.id > 0
@assert idx.id < compact.result_idx
return block_for_inst(compact, SSAValue(idx.id))
else
return block_for_inst(compact, SSAValue(compact.new_new_nodes.info[-idx.id].pos))
end
end

function dominates_ssa(compact::IncrementalCompact, domtree::DomTree, x::AnySSAValue, y::AnySSAValue)
Expand All @@ -682,16 +698,24 @@ function dominates_ssa(compact::IncrementalCompact, domtree::DomTree, x::AnySSAV
if isa(x, OldSSAValue)
x′ = compact.ssa_rename[x.id]::SSAValue
elseif isa(x, NewSSAValue)
xinfo = compact.new_new_nodes.info[x.id]
x′ = SSAValue(xinfo.pos)
if x.id > 0
x′ = SSAValue(x.id)
else
xinfo = compact.new_new_nodes.info[-x.id]
x′ = SSAValue(xinfo.pos)
end
else
x′ = x
end
if isa(y, OldSSAValue)
y′ = compact.ssa_rename[y.id]::SSAValue
elseif isa(y, NewSSAValue)
yinfo = compact.new_new_nodes.info[y.id]
y′ = SSAValue(yinfo.pos)
if y.id > 0
y′ = SSAValue(y.id)
else
yinfo = compact.new_new_nodes.info[-y.id]
y′ = SSAValue(yinfo.pos)
end
else
y′ = y
end
Expand Down Expand Up @@ -719,7 +743,8 @@ function count_added_node!(compact::IncrementalCompact, @nospecialize(v))
if isa(val, SSAValue)
compact.used_ssas[val.id] += 1
elseif isa(val, NewSSAValue)
compact.new_new_used_ssas[val.id] += 1
@assert val.id < 0 # Newly added nodes should be canonicalized
compact.new_new_used_ssas[-val.id] += 1
needs_late_fixup = true
end
end
Expand All @@ -743,7 +768,7 @@ function insert_node!(compact::IncrementalCompact, before, inst::NewInstruction,
node = add!(compact.new_new_nodes, before.id, attach_after)
push!(compact.new_new_used_ssas, 0)
node[:inst], node[:type], node[:line], node[:flag] = inst.stmt, inst.type, line, inst.flag
return NewSSAValue(node.idx)
return NewSSAValue(-node.idx)
else
line = something(inst.line, compact.ir.stmts[before.id][:line])
node = add_pending!(compact, before.id, attach_after)
Expand All @@ -762,7 +787,7 @@ function insert_node!(compact::IncrementalCompact, before, inst::NewInstruction,
node = add!(compact.new_new_nodes, renamed.id, attach_after)
push!(compact.new_new_used_ssas, 0)
node[:inst], node[:type], node[:line], node[:flag] = inst.stmt, inst.type, line, inst.flag
return NewSSAValue(node.idx)
return NewSSAValue(-node.idx)
else
if pos > length(compact.ir.stmts)
#@assert attach_after
Expand All @@ -778,12 +803,13 @@ function insert_node!(compact::IncrementalCompact, before, inst::NewInstruction,
return os
end
elseif isa(before, NewSSAValue)
before_entry = compact.new_new_nodes.info[before.id]
line = something(inst.line, compact.new_new_nodes.stmts[before.id][:line])
# TODO: This is incorrect and does not maintain ordering among the new nodes
before_entry = compact.new_new_nodes.info[-before.id]
line = something(inst.line, compact.new_new_nodes.stmts[-before.id][:line])
new_entry = add!(compact.new_new_nodes, before_entry.pos, attach_after)
new_entry[:inst], new_entry[:type], new_entry[:line], new_entry[:flag] = inst.stmt, inst.type, line, inst.flag
push!(compact.new_new_used_ssas, 0)
return NewSSAValue(new_entry.idx)
return NewSSAValue(-new_entry.idx)
else
error("Unsupported")
end
Expand Down Expand Up @@ -838,8 +864,9 @@ function kill_current_uses(compact::IncrementalCompact, @nospecialize(stmt))
@assert compact.used_ssas[val.id] >= 1
compact.used_ssas[val.id] -= 1
elseif isa(val, NewSSAValue)
@assert compact.new_new_used_ssas[val.id] >= 1
compact.new_new_used_ssas[val.id] -= 1
@assert val.id < 0
@assert compact.new_new_used_ssas[-val.id] >= 1
compact.new_new_used_ssas[-val.id] -= 1
end
end
end
Expand Down Expand Up @@ -929,11 +956,7 @@ function getindex(view::TypesView, idx::Int)
end

function getindex(view::TypesView, idx::NewSSAValue)
if isa(view.ir, IncrementalCompact)
return view.ir.new_new_nodes.stmts[idx.id][:type]
else
return view.ir.new_nodes.stmts[idx.id][:type]
end
return view.ir[idx][:type]
end

function process_phinode_values(old_values::Vector{Any}, late_fixup::Vector{Int},
Expand Down Expand Up @@ -964,8 +987,13 @@ function process_phinode_values(old_values::Vector{Any}, late_fixup::Vector{Int}
val = renumber_ssa2(SSAValue(val.id), ssa_rename, used_ssas, new_new_used_ssas, true)
end
elseif isa(val, NewSSAValue)
push!(late_fixup, result_idx)
new_new_used_ssas[val.id] += 1
if val.id < 0
push!(late_fixup, result_idx)
new_new_used_ssas[-val.id] += 1
else
@assert do_rename_ssa
val = SSAValue(val.id)
end
end
values[i] = val
end
Expand All @@ -989,8 +1017,13 @@ end

function renumber_ssa2(val::NewSSAValue, ssanums::Vector{Any}, used_ssas::Vector{Int},
new_new_used_ssas::Vector{Int}, do_rename_ssa::Bool)
new_new_used_ssas[val.id] += 1
return val
if val.id < 0
new_new_used_ssas[-val.id] += 1
return val
else
used_ssas[val.id] += 1
return SSAValue(val.id)
end
end

function renumber_ssa2!(@nospecialize(stmt), ssanums::Vector{Any}, used_ssas::Vector{Int}, new_new_used_ssas::Vector{Int}, late_fixup::Vector{Int}, result_idx::Int, do_rename_ssa::Bool)
Expand Down Expand Up @@ -1225,6 +1258,8 @@ function process_node!(compact::IncrementalCompact, result_idx::Int, inst::Instr
stmt = ssa_rename[stmt.id]
end
ssa_rename[idx] = stmt
elseif isa(stmt, NewSSAValue)
ssa_rename[idx] = SSAValue(stmt.id)
else
# Constant assign, replace uses of this ssa value with its result
ssa_rename[idx] = stmt
Expand Down Expand Up @@ -1466,7 +1501,8 @@ function fixup_node(compact::IncrementalCompact, @nospecialize(stmt))
elseif isa(stmt, PhiCNode)
return PhiCNode(fixup_phinode_values!(compact, stmt.values))
elseif isa(stmt, NewSSAValue)
return SSAValue(length(compact.result) + stmt.id)
@assert stmt.id < 0
return SSAValue(length(compact.result) - stmt.id)
elseif isa(stmt, OldSSAValue)
val = compact.ssa_rename[stmt.id]
if isa(val, SSAValue)
Expand Down
20 changes: 10 additions & 10 deletions base/compiler/ssair/passes.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -199,7 +199,7 @@ function simple_walk(compact::IncrementalCompact, @nospecialize(defssa#=::AnySSA
return rename
end
end
def = compact[defssa]
def = compact[defssa][:inst]
if isa(def, PiNode)
if callback(def, defssa)
return defssa
Expand Down Expand Up @@ -246,7 +246,7 @@ Starting at `val` walk use-def chains to get all the leaves feeding into this `v
function walk_to_defs(compact::IncrementalCompact, @nospecialize(defssa), @nospecialize(typeconstraint))
visited_phinodes = AnySSAValue[]
isa(defssa, AnySSAValue) || return Any[defssa], visited_phinodes
def = compact[defssa]
def = compact[defssa][:inst]
isa(def, PhiNode) || return Any[defssa], visited_phinodes
visited_constraints = IdDict{AnySSAValue, Any}()
worklist_defs = AnySSAValue[]
Expand All @@ -258,7 +258,7 @@ function walk_to_defs(compact::IncrementalCompact, @nospecialize(defssa), @nospe
defssa = pop!(worklist_defs)
typeconstraint = pop!(worklist_constraints)
visited_constraints[defssa] = typeconstraint
def = compact[defssa]
def = compact[defssa][:inst]
if isa(def, PhiNode)
push!(visited_phinodes, defssa)
possible_predecessors = Int[]
Expand Down Expand Up @@ -479,12 +479,12 @@ function walk_to_def(compact::IncrementalCompact, @nospecialize(leaf))
leaf = simple_walk(compact, leaf)
end
if isa(leaf, AnySSAValue)
def = compact[leaf]
def = compact[leaf][:inst]
else
def = leaf
end
elseif isa(leaf, AnySSAValue)
def = compact[leaf]
def = compact[leaf][:inst]
else
def = leaf
end
Expand Down Expand Up @@ -653,7 +653,7 @@ function perform_lifting!(compact::IncrementalCompact,
cached = false
if cached
ssa = lifting_cache[ckey]
push!(lifted_phis, LiftedPhi(ssa, compact[ssa]::PhiNode, false))
push!(lifted_phis, LiftedPhi(ssa, compact[ssa][:inst]::PhiNode, false))
continue
end
n = PhiNode()
Expand All @@ -664,7 +664,7 @@ function perform_lifting!(compact::IncrementalCompact,

# Fix up arguments
for (old_node_ssa, lf) in zip(visited_phinodes, lifted_phis)
old_node = compact[old_node_ssa]::PhiNode
old_node = compact[old_node_ssa][:inst]::PhiNode
new_node = lf.node
lf.need_argupdate || continue
for i = 1:length(old_node.edges)
Expand Down Expand Up @@ -790,7 +790,7 @@ function sroa_pass!(ir::IRCode, inlining::Union{Nothing, InliningState} = nothin
def = simple_walk(compact, preserved_arg, callback)
isa(def, SSAValue) || continue
defidx = def.id
def = compact[defidx]
def = compact[def][:inst]
if is_known_call(def, tuple, compact)
record_immutable_preserve!(new_preserves, def, compact)
push!(preserved, preserved_arg.id)
Expand Down Expand Up @@ -1289,7 +1289,7 @@ function mark_phi_cycles!(compact::IncrementalCompact, safe_phis::SPCSet, phi::I
for ur in userefs(compact.result[phi][:inst])
val = ur[]
isa(val, SSAValue) || continue
isa(compact[val], PhiNode) || continue
isa(compact[val][:inst], PhiNode) || continue
(val.id in safe_phis) && continue
push!(worklist, val.id)
end
Expand Down Expand Up @@ -1399,7 +1399,7 @@ function adce_pass!(ir::IRCode)
continue
end
to_drop = Int[]
stmt = compact[phi]
stmt = compact[SSAValue(phi)][:inst]
stmt === nothing && continue
stmt = stmt::PhiNode
for i = 1:length(stmt.values)
Expand Down
12 changes: 6 additions & 6 deletions base/compiler/ssair/slot2ssa.jl
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -562,7 +562,7 @@ function compute_live_ins(cfg::CFG, defs::Vector{Int}, uses::Vector{Int})
BlockLiveness(bb_defs, bb_uses)
end

function recompute_type(node::Union{PhiNode, PhiCNode}, ci::CodeInfo, ir::IRCode, sptypes::Vector{Any}, slottypes::Vector{Any})
function recompute_type(node::Union{PhiNode, PhiCNode}, ci::CodeInfo, ir::IRCode, sptypes::Vector{Any}, slottypes::Vector{Any}, nstmts::Int)
new_typ = Union{}
for i = 1:length(node.values)
if isa(node, PhiNode) && !isassigned(node.values, i)
Expand All @@ -579,7 +579,7 @@ function recompute_type(node::Union{PhiNode, PhiCNode}, ci::CodeInfo, ir::IRCode
end
@assert !isa(typ, MaybeUndef)
while isa(typ, DelayedTyp)
typ = types(ir)[typ.phi::NewSSAValue]
typ = types(ir)[new_to_regular(typ.phi::NewSSAValue, nstmts)]
end
new_typ = tmerge(new_typ, was_maybe_undef ? MaybeUndef(typ) : typ)
end
Expand Down Expand Up @@ -856,7 +856,7 @@ function construct_ssa!(ci::CodeInfo, ir::IRCode, domtree::DomTree,
orig_typ = typ = typ_for_val(phic_values[i], ci, ir.sptypes, -1, slottypes)
@assert !isa(typ, MaybeUndef)
while isa(typ, DelayedTyp)
typ = types(ir)[typ.phi::NewSSAValue]
typ = types(ir)[new_to_regular(typ.phi::NewSSAValue, nstmts)]
end
new_typ = tmerge(new_typ, typ)
end
Expand All @@ -871,7 +871,7 @@ function construct_ssa!(ci::CodeInfo, ir::IRCode, domtree::DomTree,
changed = false
for new_idx in type_refine_phi
node = new_nodes.stmts[new_idx]
new_typ = recompute_type(node[:inst]::Union{PhiNode,PhiCNode}, ci, ir, ir.sptypes, slottypes)
new_typ = recompute_type(node[:inst]::Union{PhiNode,PhiCNode}, ci, ir, ir.sptypes, slottypes, nstmts)
if !(node[:type] ⊑ new_typ) || !(new_typ ⊑ node[:type])
node[:type] = new_typ
changed = true
Expand All @@ -881,14 +881,14 @@ function construct_ssa!(ci::CodeInfo, ir::IRCode, domtree::DomTree,
for i in 1:length(result_types)
rt_i = result_types[i]
if rt_i isa DelayedTyp
result_types[i] = types(ir)[rt_i.phi::NewSSAValue]
result_types[i] = types(ir)[new_to_regular(rt_i.phi::NewSSAValue, nstmts)]
end
end
for i = 1:length(new_nodes)
local node = new_nodes.stmts[i]
local typ = node[:type]
if isa(typ, DelayedTyp)
node[:type] = types(ir)[typ.phi::NewSSAValue]
node[:type] = types(ir)[new_to_regular(typ.phi::NewSSAValue, nstmts)]
end
end
# Renumber SSA values
Expand Down