simpler and faster deepcopy_internal for BigInt and BigFloat (JuliaLa…

…ng#41011)

base/gmp.jl

@@ -758,14 +758,7 @@ Base.add_with_overflow(a::BigInt, b::BigInt) = a + b, false
 Base.sub_with_overflow(a::BigInt, b::BigInt) = a - b, false
 Base.mul_with_overflow(a::BigInt, b::BigInt) = a * b, false
 
-function Base.deepcopy_internal(x::BigInt, stackdict::IdDict)
- if haskey(stackdict, x)
- return stackdict[x]
- end
- y = MPZ.set(x)
- stackdict[x] = y
- return y
-end
+Base.deepcopy_internal(x::BigInt, stackdict::IdDict) = get!(() -> MPZ.set(x), stackdict, x)
 
 ## streamlined hashing for BigInt, by avoiding allocation from shifts ##
 

base/mpfr.jl

@@ -1021,14 +1021,14 @@ set_emax!(x) = check_exponent_err(ccall((:mpfr_set_emax, :libmpfr), Cint, (Clong
 set_emin!(x) = check_exponent_err(ccall((:mpfr_set_emin, :libmpfr), Cint, (Clong,), x))
 
 function Base.deepcopy_internal(x::BigFloat, stackdict::IdDict)
- haskey(stackdict, x) && return stackdict[x]
- # d = copy(x._d)
- d = x._d
- d′ = GC.@preserve d unsafe_string(pointer(d), sizeof(d)) # creates a definitely-new String
- y = _BigFloat(x.prec, x.sign, x.exp, d′)
- #ccall((:mpfr_custom_move,:libmpfr), Cvoid, (Ref{BigFloat}, Ptr{Limb}), y, d) # unnecessary
- stackdict[x] = y
- return y
+ get!(stackdict, x) do
+  # d = copy(x._d)
+  d = x._d
+  d′ = GC.@preserve d unsafe_string(pointer(d), sizeof(d)) # creates a definitely-new String
+  y = _BigFloat(x.prec, x.sign, x.exp, d′)
+  #ccall((:mpfr_custom_move,:libmpfr), Cvoid, (Ref{BigFloat}, Ptr{Limb}), y, d) # unnecessary
+  return y
+ end
 end
 
 function decompose(x::BigFloat)::Tuple{BigInt, Int, Int}