From baa9b2733c0ee0c16eb8f0c67af9540a64c1eb18 Mon Sep 17 00:00:00 2001
From: Jeff Bezanson <jeff.bezanson@gmail.com>
Date: Fri, 19 Jun 2020 11:07:24 -0400
Subject: [PATCH] set default max_methods to 3

---
 base/compiler/types.jl |  4 ++--
 test/worlds.jl         | 17 +++++++++++++++--
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/base/compiler/types.jl b/base/compiler/types.jl
index 068574b80d0c9..d371b6a1c8786 100644
--- a/base/compiler/types.jl
+++ b/base/compiler/types.jl
@@ -58,7 +58,7 @@ struct OptimizationParams
             inline_cost_threshold::Int = 100,
             inline_nonleaf_penalty::Int = 1000,
             inline_tupleret_bonus::Int = 400,
-            max_methods::Int = 4,
+            max_methods::Int = 3,
             tuple_splat::Int = 32,
             union_splitting::Int = 4,
         )
@@ -107,7 +107,7 @@ struct InferenceParams
     function InferenceParams(;
             ipo_constant_propagation::Bool = true,
             aggressive_constant_propagation::Bool = false,
-            max_methods::Int = 4,
+            max_methods::Int = 3,
             union_splitting::Int = 4,
             apply_union_enum::Int = 8,
             tupletype_depth::Int = 3,
diff --git a/test/worlds.jl b/test/worlds.jl
index 92ee5866e1517..878dd24adadb4 100644
--- a/test/worlds.jl
+++ b/test/worlds.jl
@@ -275,11 +275,12 @@ applyf35855(Any[1])
 wany3 = worlds(instance(applyf35855, (Vector{Any},)))
 src3 = code_typed(applyf35855, (Vector{Any},))[1]
 @test (wany3 == wany2) == equal(src3, src2)   # don't invalidate unless you also change the code
-f35855(::AbstractVector) = 4         # next test would pass if this were ::Vector{Int}
+f35855(::AbstractVector) = 4
 applyf35855(Any[1])
 wany4 = worlds(instance(applyf35855, (Vector{Any},)))
 src4 = code_typed(applyf35855, (Vector{Any},))[1]
-@test_broken (wany4 == wany3) == equal(src4, src3)
+# this passes when max_methods == 3, fails when set to 4
+@test (wany4 == wany3) == equal(src4, src3)
 f35855(::Dict) = 5
 applyf35855(Any[1])
 wany5 = worlds(instance(applyf35855, (Vector{Any},)))
@@ -291,6 +292,18 @@ wany6 = worlds(instance(applyf35855, (Vector{Any},)))
 src6 = code_typed(applyf35855, (Vector{Any},))[1]
 @test (wany6 == wany5) == equal(src6, src5)
 
+applyf35855_2(c) = f35855_2(c[1])
+f35855_2(::Int) = 1
+f35855_2(::Float64) = 2
+applyf35855_2(Any[1])
+wany3 = worlds(instance(applyf35855_2, (Vector{Any},)))
+src3 = code_typed(applyf35855_2, (Vector{Any},))[1]
+f35855_2(::AbstractVector) = 4         # next test would pass if this were ::Vector{Int}
+applyf35855_2(Any[1])
+wany4 = worlds(instance(applyf35855_2, (Vector{Any},)))
+src4 = code_typed(applyf35855_2, (Vector{Any},))[1]
+@test_broken (wany4 == wany3) == equal(src4, src3)
+
 ## ambiguities do not trigger invalidation
 using Printf
 Printf.gen("%f")