simplify contract pass

Author: chriselrod

src/vectorizationbase_compat/contract_pass.jl

@@ -11,42 +11,32 @@ function mulexprcost(@nospecialize(x::ProdArg))::Int
     return base + length(ex.args)
   end
 end
-function mul_fast_expr(args::SubArray{Any, 1, Vector{Any}, Tuple{UnitRange{Int64}}, true})::Expr
+function mul_fast_expr(
+  args::SubArray{Any,1,Vector{Any},Tuple{UnitRange{Int64}},true}
+)::Expr
   b = Expr(:call, :mul_fast)
   for i ∈ 2:length(args)
     push!(b.args, args[i])
   end
   b
 end
-function mulexpr(mulexargs::SubArray{Any, 1, Vector{Any}, Tuple{UnitRange{Int64}}, true})::Tuple{ProdArg,ProdArg}
+function mulexpr(
+  mulexargs::SubArray{Any,1,Vector{Any},Tuple{UnitRange{Int64}},true}
+)::Tuple{ProdArg,ProdArg}
   a = (mulexargs[1])::ProdArg
-  if length(mulexargs) == 2
-    return (a, mulexargs[2]::ProdArg)
-  elseif length(mulexargs) == 3
-    # We'll calc the product between the guesstimated cheaper two args first, for better out of order execution
-    b = (mulexargs[2])::ProdArg
-    c = (mulexargs[3])::ProdArg
-    ac = mulexprcost(a)
-    bc = mulexprcost(b)
-    cc = mulexprcost(c)
-    maxc = max(ac, bc, cc)
-    if ac == maxc
-      return (a, Expr(:call, :mul_fast, b, c))
-    elseif bc == maxc
-      return (b, Expr(:call, :mul_fast, a, c))
-    else
-      return (c, Expr(:call, :mul_fast, a, b))
-    end
-  else
-    return (a, mul_fast_expr(mulexargs))
-  end
-  a = (mulexargs[1])::Union{Symbol,Expr,Number}
-  b = if length(mulexargs) == 2 # two arg mul
-    (mulexargs[2])::Union{Symbol,Expr,Number}
-  else
-    mul_fast_expr(mulexargs)
-  end
-  a, b
+  Nexpr = length(mulexargs)
+  Nexpr == 2 && (a, mulexargs[2]::ProdArg)
+  Nexpr != 3 && (a, mul_fast_expr(mulexargs))
+  # We'll calc the product between the guesstimated cheaper two args first, for better out of order execution
+  b = (mulexargs[2])::ProdArg
+  c = (mulexargs[3])::ProdArg
+  ac = mulexprcost(a)
+  bc = mulexprcost(b)
+  cc = mulexprcost(c)
+  maxc = max(ac, bc, cc)
+  ac == maxc && return (a, Expr(:call, :mul_fast, b, c))
+  bc == maxc && return (b, Expr(:call, :mul_fast, c, a))
+  return (c, Expr(:call, :mul_fast, a, b))
 end
 function append_args_skip!(call, args, i, mod)
   for j ∈ eachindex(args)
@@ -228,7 +218,8 @@ function capture_a_muladd(ex::Expr, mod)
   end
   true, call
 end
-capture_muladd(ex::Expr, mod) = while true
+capture_muladd(ex::Expr, mod) =
+  while true
     ex.head === :ref && return ex
     if Meta.isexpr(ex, :call, 2)
       if (ex.args[1] === :(-))