Merge pull request #26306 from JuliaLang/kf/domsort

[NewOptimizer] Domsort basic blocks

Author: Keno

base/compiler/optimize.jl

@@ -4194,8 +4194,7 @@ function copy_duplicated_expr_pass!(sv::OptimizationState)
 end
 
 # fix label numbers to always equal the statement index of the label
-function reindex_labels!(sv::OptimizationState)
-    body = sv.src.code
+function reindex_labels!(body::Vector{Any})
     mapping = get_label_map(body)
     for i = 1:length(body)
         el = body[i]
@@ -4235,6 +4234,11 @@ function reindex_labels!(sv::OptimizationState)
     end
 end
 
+
+function reindex_labels!(sv::OptimizationState)
+    reindex_labels!(sv.src.code)
+end
+
 function return_type(@nospecialize(f), @nospecialize(t))
     params = Params(ccall(:jl_get_tls_world_age, UInt, ()))
     rt = Union{}

base/compiler/ssair/domtree.jl

@@ -94,4 +94,4 @@ function construct_domtree(cfg)
     # Recursively set level
     update_level!(domtree, 1, 1)
     DomTree(idoms, domtree)
-end
+end

base/compiler/ssair/driver.jl

@@ -65,7 +65,9 @@ function normalize(@nospecialize(stmt), meta::Vector{Any}, table::Vector{LineInf
         elseif stmt.head === :gotoifnot
             return GotoIfNot(stmt.args...)
         elseif stmt.head === :return
-            return ReturnNode{Any}(stmt.args...)
+            return ReturnNode((length(stmt.args) == 0 ? (nothing,) : stmt.args)...)
+        elseif stmt.head === :unreachable
+            return ReturnNode()
         end
     elseif isa(stmt, LabelNode)
         return nothing
@@ -89,6 +91,23 @@ end
 function run_passes(ci::CodeInfo, nargs::Int, linetable::Vector{LineInfoNode})
     mod = linetable[1].mod
     ci.code = copy(ci.code)
+    # Go through and add an unreachable node after every
+    # Union{} call. Then reindex labels.
+    idx = 1
+    while idx <= length(ci.code)
+        stmt = ci.code[idx]
+        if isexpr(stmt, :(=))
+            stmt = stmt.args[2]
+        end
+        if isa(stmt, Expr) && stmt.typ === Union{}
+            if !(idx < length(ci.code) && isexpr(ci.code[idx+1], :unreachable))
+                insert!(ci.code, idx + 1, ReturnNode())
+                idx += 1
+            end
+        end
+        idx += 1
+    end
+    reindex_labels!(ci.code)
     meta = Any[]
     lines = fill(0, length(ci.code))
     let loc = RefValue(1)
@@ -110,6 +129,7 @@ function run_passes(ci::CodeInfo, nargs::Int, linetable::Vector{LineInfoNode})
             IRCode(code, lines, cfg, argtypes, mod, meta)
         end
     ir = construct_ssa!(ci, ir, domtree, defuse_insts, nargs)
+    domtree = construct_domtree(ir.cfg)
     ir = compact!(ir)
     verify_ir(ir)
     ir = type_lift_pass!(ir)

base/compiler/ssair/ir.jl

@@ -11,10 +11,11 @@ struct GotoIfNot
     GotoIfNot(@nospecialize(cond), dest::Int) = new(cond, dest)
 end
 
-struct ReturnNode{T}
-    val::T
-    ReturnNode{T}(@nospecialize(val)) where {T} = new{T}(val::T)
-    ReturnNode{T}() where {T} = new{T}()
+struct ReturnNode
+    val
+    ReturnNode(@nospecialize(val)) = new(val)
+    # unassigned val indicates unreachable
+    ReturnNode() = new()
 end
 
 """
@@ -31,6 +32,8 @@ start(r::StmtRange) = 0
 done(r::StmtRange, state) = r.last - r.first < state
 next(r::StmtRange, state) = (r.first + state, state + 1)
 
+StmtRange(range::UnitRange{Int}) = StmtRange(first(range), last(range))
+
 struct BasicBlock
     stmts::StmtRange
     preds::Vector{Int}
@@ -264,7 +267,7 @@ function done(it::UseRefIterator, use)
     false
 end
 
-function scan_ssa_use!(used::IdSet{Int64}, @nospecialize(stmt))
+function scan_ssa_use!(used, @nospecialize(stmt))
     if isa(stmt, SSAValue)
         push!(used, stmt.id)
     end
@@ -340,9 +343,9 @@ mutable struct IncrementalCompact
 end
 
 struct TypesView
-    compact::IncrementalCompact
+    ir::Union{IRCode, IncrementalCompact}
 end
-types(compact::IncrementalCompact) = TypesView(compact)
+types(ir::Union{IRCode, IncrementalCompact}) = TypesView(ir)
 
 function getindex(compact::IncrementalCompact, idx)
     if idx < compact.result_idx
@@ -368,10 +371,16 @@ function setindex!(compact::IncrementalCompact, v, idx)
 end
 
 function getindex(view::TypesView, idx)
-    if idx < view.compact.result_idx
+    isa(idx, SSAValue) && (idx = idx.id)
+    if isa(view.ir, IncrementalCompact) && idx < view.compact.result_idx
         return view.compact.result_types[idx]
     else
-        return view.compact.ir.types[idx]
+        ir = isa(view.ir, IncrementalCompact) ? view.ir.ir : view.ir
+        if idx <= length(ir.types)
+            return ir.types[idx]
+        else
+            return ir.new_nodes[idx - length(ir.types)][2]
+        end
     end
 end
 
@@ -457,7 +466,7 @@ function next(compact::IncrementalCompact, (idx, active_bb, old_result_idx)::Tup
         compact.result_types[old_result_idx] = typ
         compact.result_lines[old_result_idx] = new_line
         result_idx = process_node!(compact, old_result_idx, new_node, new_idx, idx)
-        (old_result_idx == result_idx) && return next(compact, (idx, result_idx))
+        (old_result_idx == result_idx) && return next(compact, (idx, active_bb, result_idx))
         compact.result_idx = result_idx
         return (old_result_idx, compact.result[old_result_idx]), (compact.idx, active_bb, compact.result_idx)
     end

base/compiler/ssair/legacy.jl

@@ -159,7 +159,7 @@ function replace_code!(ci::CodeInfo, code::IRCode, nargs::Int, linetable::Vector
                 new_stmt = Expr(:return, rename(stmt.val))
             else
                 # Unreachable, so no issue with this
-                new_stmt = nothing
+                new_stmt = Expr(:unreachable)
             end
         elseif isa(stmt, SSAValue)
             new_stmt = rename(stmt)

base/compiler/ssair/passes.jl

@@ -35,7 +35,7 @@ function type_lift_pass!(ir::IRCode)
                     def = ir.stmts[item]
                     edges = copy(def.edges)
                     values = Vector{Any}(uninitialized, length(edges))
-                    new_phi = insert_node!(ir, item, Bool, PhiNode(edges, values))
+                    new_phi = length(values) == 0 ? false : insert_node!(ir, item, Bool, PhiNode(edges, values))
                     processed[item] = new_phi
                     if first
                         lifted_undef[stmt_id] = new_phi

base/compiler/ssair/show.jl

@@ -80,9 +80,10 @@ function Base.show(io::IO, code::IRCode)
         bbrange = cfg.blocks[bb_idx].stmts
         bbrange = bbrange.first:bbrange.last
         bb_pad = max_bb_idx_size - length(string(bb_idx))
+        bb_start_str = string("$(bb_idx) ",length(cfg.blocks[bb_idx].preds) <= 1 ? "─" : "┄",  "─"^(bb_pad)," ")
         if idx != last(bbrange)
             if idx == first(bbrange)
-                print(io, "$(bb_idx) ","─"^(1+bb_pad)," ")
+                print(io, bb_start_str)
             else
                 print(io, "│  "," "^max_bb_idx_size)
             end
@@ -98,7 +99,7 @@ function Base.show(io::IO, code::IRCode)
             node_idx += length(code.stmts)
             if print_sep
                 if floop
-                    print(io, "$(bb_idx) ","─"^(1+bb_pad)," ")
+                    print(io, bb_start_str)
                 else
                     print(io, "│  "," "^max_bb_idx_size)
                 end
@@ -117,7 +118,7 @@ function Base.show(io::IO, code::IRCode)
         end
         if print_sep
             if idx == first(bbrange) && floop
-                print(io, "$(bb_idx) ","─"^(1+bb_pad)," ")
+                print(io, bb_start_str)
             else
                 print(io, idx == last(bbrange) ? string("└", "─"^(1+max_bb_idx_size), " ") :
                     string("│  ", " "^max_bb_idx_size))