Support semi concrete eval (#319)

Co-authored-by: Shuhei Kadowaki <aviatesk@gmail.com> Co-authored-by: Keno Fisher <keno@juliacomputing.com>
JuliaDebug · Sep 5, 2022 · 6a5a21b · 6a5a21b
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Showing 6 changed files with 115 additions and 30 deletions.
diff --git a/src/Cthulhu.jl b/src/Cthulhu.jl
@@ -282,6 +282,7 @@ end
     @static if VERSION ≥ v"1.9.0-DEV.409"
         get_effects(result::CC.ConstPropResult) = get_effects(result.result)
         get_effects(result::CC.ConcreteResult) = result.effects
+        get_effects(result::CC.SemiConcreteResult) = result.effects
     else
         get_effects(result::CC.ConstResult) = result.effects
     end
@@ -380,8 +381,19 @@ function lookup_constproped_unoptimized(interp::CthulhuInterpreter, override::In
     return (; src, rt, infos, slottypes, effects, codeinf)
 end
 
+function lookup_semiconcrete(interp::CthulhuInterpreter, override::SemiConcreteCallInfo, optimize::Bool)
+    src = CC.copy(override.ir)
+    rt = get_rt(override)
+    infos = src.stmts.info
+    slottypes = src.argtypes
+    effects = get_effects(override)
+    (; codeinf) = lookup(interp, get_mi(override), optimize)
+    return (; src, rt, infos, slottypes, effects, codeinf)
+end
+
 function get_override(@nospecialize(info))
     isa(info, ConstPropCallInfo) && return info.result
+    isa(info, SemiConcreteCallInfo) && return info
     isa(info, OCCallInfo) && return get_override(info.ci)
     return nothing
 end
@@ -392,7 +404,7 @@ end
 # src/ui.jl provides the user facing interface to which _descend responds
 ##
 function _descend(term::AbstractTerminal, interp::AbstractInterpreter, curs::AbstractCursor;
-    override::Union{Nothing,InferenceResult} = nothing,
+    override::Union{Nothing,InferenceResult,SemiConcreteCallInfo} = nothing,
     debuginfo::Union{Symbol,DebugInfo}       = CONFIG.debuginfo,                     # default is compact debuginfo
     optimize::Bool                           = CONFIG.optimize,                      # default is true
     interruptexc::Bool                       = CONFIG.interruptexc,
@@ -434,8 +446,10 @@ function _descend(term::AbstractTerminal, interp::AbstractInterpreter, curs::Abs
         """)
     end
     while true
-        if override !== nothing
+        if isa(override, InferenceResult)
             (; src, rt, infos, slottypes, codeinf, effects) = lookup_constproped(interp, curs, override, optimize)
+        elseif isa(override, SemiConcreteCallInfo)
+                (; src, rt, infos, slottypes, codeinf, effects) = lookup_semiconcrete(interp, curs, override, optimize)
         else
             if optimize
                 codeinst = get_optimized_codeinst(interp, curs)
@@ -466,7 +480,7 @@ function _descend(term::AbstractTerminal, interp::AbstractInterpreter, curs::Abs
         end
         mi = get_mi(curs)
         src = preprocess_ci!(src, mi, optimize, CONFIG)
-        if optimize # optimization might have deleted some statements
+        if optimize || isa(src, IRCode) # optimization might have deleted some statements
             infos = src.stmts.info
         else
             @assert length(src.code) == length(infos)

diff --git a/src/callsite.jl b/src/callsite.jl
@@ -138,6 +138,14 @@ get_mi(ceci::ConcreteCallInfo) = get_mi(ceci.mi)
 get_rt(ceci::ConcreteCallInfo) = get_rt(ceci.mi)
 get_effects(ceci::ConcreteCallInfo) = get_effects(ceci.mi)
 
+struct SemiConcreteCallInfo <: CallInfo
+    mi::CallInfo
+    ir::IRCode
+end
+get_mi(scci::SemiConcreteCallInfo) = get_mi(scci.mi)
+get_rt(scci::SemiConcreteCallInfo) = get_rt(scci.mi)
+get_effects(scci::SemiConcreteCallInfo) = get_effects(scci.mi)
+
 # CUDA callsite
 struct CuCallInfo <: CallInfo
      cumi::MICallInfo
@@ -309,6 +317,13 @@ function show_callinfo(limiter, ci::ConstPropCallInfo)
     __show_limited(limiter, name, tt, get_rt(ci), get_effects(ci))
 end
 
+function show_callinfo(limiter, ci::SemiConcreteCallInfo)
+    # XXX: The first argument could be const-overriden too
+    name = get_mi(ci).def.name
+    tt = ci.ir.argtypes[2:end]
+    __show_limited(limiter, name, tt, get_rt(ci), get_effects(ci))
+end
+
 function show_callinfo(limiter, ci::ConcreteCallInfo)
     # XXX: The first argument could be const-overriden too
     name = get_mi(ci).def.name
@@ -373,6 +388,11 @@ function print_callsite_info(limiter::IO, info::ConstPropCallInfo)
     show_callinfo(limiter, info)
 end
 
+function print_callsite_info(limiter::IO, info::SemiConcreteCallInfo)
+    print(limiter, " = < semi-concrete eval > ")
+    show_callinfo(limiter, info)
+end
+
 function print_callsite_info(limiter::IO, info::ConcreteCallInfo)
     print(limiter, "< concrete eval > ")
     show_callinfo(limiter, info)

diff --git a/src/interface.jl b/src/interface.jl
@@ -28,6 +28,13 @@ missing `$AbstractCursor` API:
 lookup_constproped(interp::CthulhuInterpreter, ::CthulhuCursor, override::InferenceResult, optimize::Bool) =
     lookup_constproped(interp, override, optimize)
 
+lookup_semiconcrete(interp::AbstractInterpreter, curs::AbstractCursor, override::SemiConcreteCallInfo, optimize::Bool) = error(lazy"""
+missing `$AbstractCursor` API:
+`$(typeof(curs))` is required to implement the `$lookup_semicocnrete(interp::$(typeof(interp)), curs::$(typeof(curs)), override::SemiConcreteCallInfo, optimize::Bool)` interface.
+""")
+lookup_semiconcrete(interp::CthulhuInterpreter, ::CthulhuCursor, override::SemiConcreteCallInfo, optimize::Bool) =
+    lookup_semiconcrete(interp, override, optimize)
+
 get_mi(curs::AbstractCursor) = error(lazy"""
 missing `$AbstractCursor` API:
 `$(typeof(curs))` is required to implement the `$get_mi(curs::$(typeof(curs))) -> MethodInstance` interface.

diff --git a/src/interpreter.jl b/src/interpreter.jl
@@ -192,6 +192,13 @@ function CC.inlining_policy(interp::CthulhuInterpreter)
 end
 end # @static if isdefined(CC, :is_stmt_inline)
 
+@static if isdefined(CC, :codeinst_to_ir)
+function CC.codeinst_to_ir(interp::CthulhuInterpreter, code::CodeInstance)
+    isa(code.inferred, Nothing) && return nothing
+    return CC.copy((code.inferred::OptimizedSource).ir)
+end
+end # @static if isdefined(CC, :codeinst_to_ir)
+
 function CC.finish!(interp::CthulhuInterpreter, caller::InferenceResult)
     effects = EFFECTS_ENABLED ? caller.ipo_effects : nothing
     caller.src = create_cthulhu_source(caller.src, effects)

diff --git a/src/reflection.jl b/src/reflection.jl
@@ -115,6 +115,11 @@ function process_const_info(interp::AbstractInterpreter, @nospecialize(thisinfo)
         effects = get_effects(result)
         mici = MICallInfo(linfo, rt, effects)
         return ConstPropCallInfo(is_cached(optimize ? linfo : result) ? mici : UncachedCallInfo(mici), result)
+    elseif (@static isdefined(CC, :SemiConcreteResult) && true) && isa(result, CC.SemiConcreteResult)
+        linfo = result.mi
+        effects = get_effects(result)
+        mici = MICallInfo(linfo, rt, effects)
+        return SemiConcreteCallInfo(mici, result.ir)
     elseif (@static isdefined(CC, :ConstResult) && true) && isa(result, CC.ConstResult)
         linfo = result.mi
         effects = get_effects(result)

diff --git a/test/test_Cthulhu.jl b/test/test_Cthulhu.jl
@@ -237,32 +237,59 @@ end
             @test occursin("= < constprop > getproperty(", String(take!(io)))
         end
     end
+end
 
-    @static isdefined(Core.Compiler, :ConstResult) && @testset "ConstResult" begin
-        # constant prop' on all the splits
-        let callsites = (@eval Module() begin
-                Base.@assume_effects :terminates_locally function issue41694(x)
-                    res = 1
-                    1 < x < 20 || throw("bad")
-                    while x > 1
-                        res *= x
-                        x -= 1
-                    end
-                    return res
-                end
+Base.@assume_effects :terminates_locally function issue41694(x)
+    res = 1
+    1 < x < 20 || throw("bad")
+    while x > 1
+        res *= x
+        x -= 1
+    end
+    return res
+end
+@static isdefined(Core.Compiler, :ConstResult) && @testset "ConstResult" begin
+    # constant prop' on all the splits
+    let callsites = find_callsites_by_ftt(; optimize = false) do
+            issue41694(12)
+        end
+        callinfo = only(callsites).info
+        @test isa(callinfo, Cthulhu.ConcreteCallInfo)
+        @test Cthulhu.get_rt(callinfo) == Core.Const(factorial(12))
+        @test Cthulhu.get_effects(callinfo) |> Core.Compiler.is_foldable
+        io = IOBuffer()
+        print(io, only(callsites))
+        @test occursin("= < concrete eval > issue41694(::Core.Const(12))", String(take!(io)))
+    end
+end
 
-                $find_callsites_by_ftt(; optimize = false) do
-                    issue41694(12)
-                end
-            end)
-            callinfo = only(callsites).info
-            @test isa(callinfo, Cthulhu.ConcreteCallInfo)
-            @test Cthulhu.get_rt(callinfo) == Core.Const(factorial(12))
-            @test Cthulhu.get_effects(callinfo) |> Core.Compiler.is_foldable
-            io = IOBuffer()
-            print(io, only(callsites))
-            @test occursin("= < concrete eval > issue41694(::Core.Const(12))", String(take!(io)))
+let # check the performance benefit of semi concrete evaluation
+    param = 1000
+    ex = Expr(:block)
+    var = gensym()
+    push!(ex.args, :($var = x))
+    for _ = 1:param
+        newvar = gensym()
+        push!(ex.args, :($newvar = sin($var)))
+        var = newvar
+    end
+    @eval global Base.@constprop :aggressive Base.@assume_effects :nothrow function semi_concrete_eval(x::Int, _::Int)
+        out = $ex
+        out
+    end
+end
+@static isdefined(Core.Compiler, :SemiConcreteResult) && @testset "SemiConcreteResult" begin
+    # constant prop' on all the splits
+    let callsites = find_callsites_by_ftt((Int,); optimize = false) do x
+            semi_concrete_eval(42, x)
         end
+        callinfo = only(callsites).info
+        @test isa(callinfo, Cthulhu.SemiConcreteCallInfo)
+        @test Cthulhu.get_rt(callinfo) == Core.Const(semi_concrete_eval(42, 0))
+        # @test Cthulhu.get_effects(callinfo) |> Core.Compiler.is_semiconcrete_eligible
+        io = IOBuffer()
+        print(io, only(callsites))
+        @test occursin("= < semi-concrete eval > semi_concrete_eval(::Core.Const(42),::$Int)", String(take!(io)))
     end
 end
 
@@ -402,7 +429,7 @@ invoke_constcall(a::Number, c::Bool) = c ? Number : :number
         @test info.ci.rt === Core.Compiler.Const(:Int)
     end
 
-    # const prop' callsite
+    # const prop' / semi-concrete callsite
     @static hasfield(Core.Compiler.InvokeCallInfo, :result) && let callsites = find_callsites_by_ftt((Any,); optimize=false) do a
             Base.@invoke invoke_constcall(a::Any, true::Bool)
         end
@@ -411,12 +438,17 @@ invoke_constcall(a::Number, c::Bool) = c ? Number : :number
         @test isa(info, Cthulhu.InvokeCallInfo)
         @static Cthulhu.EFFECTS_ENABLED && Cthulhu.get_effects(info) |> Core.Compiler.is_total
         inner = info.ci
-        @test isa(inner, Cthulhu.ConstPropCallInfo)
         rt = Core.Compiler.Const(Any)
-        @test inner.result.result === rt
+        @test Cthulhu.get_rt(info) === rt
         buf = IOBuffer()
         show(buf, callsite)
-        @test occursin("= invoke < invoke_constcall(::Any,::$(Core.Compiler.Const(true)))::$rt", String(take!(buf)))
+        @static if isdefined(Core.Compiler, :SemiConcreteResult)
+            @test isa(inner, Cthulhu.SemiConcreteCallInfo)
+            @test occursin("= invoke < invoke_constcall(::Any,::$(Core.Compiler.Const(true)))::$rt", String(take!(buf)))
+        else
+            @test isa(inner, Cthulhu.ConstPropCallInfo)
+            @test occursin("= invoke < invoke_constcall(::Any,::$(Core.Compiler.Const(true)))::$rt", String(take!(buf)))
+        end
     end
 end