Fix _unsafe_trunc for BigFloat on ARM (#203)

This also moves `_unsafe_trunc` to "src/utilities.jl".

Project.toml

@@ -1,6 +1,6 @@
 name = "FixedPointNumbers"
 uuid = "53c48c17-4a7d-5ca2-90c5-79b7896eea93"
-version = "0.8.3"
+version = "0.8.4"
 
 [deps]
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"

src/fixed.jl

@@ -54,7 +54,7 @@ end
 
 function _convert(::Type{F}, x::Integer) where {T, f, F <: Fixed{T,f}}
     if ((typemin(T) >> f) <= x) & (x <= (typemax(T) >> f))
-        reinterpret(F, unsafe_trunc(T, x) << f)
+        reinterpret(F, _unsafe_trunc(T, x) << f)
     else
         throw_converterror(F, x)
     end

src/normed.jl

@@ -324,12 +324,3 @@ end
     end
     :(Normed{$T,$f})
 end
-
-_unsafe_trunc(::Type{T}, x::Integer) where {T} = x % T
-_unsafe_trunc(::Type{T}, x) where {T}          = unsafe_trunc(T, x)
-if !signbit(signed(unsafe_trunc(UInt, -12.345)))
-    # a workaround for 32-bit ARMv7 (issue #134)
-    function _unsafe_trunc(::Type{T}, x::AbstractFloat) where {T}
-        unsafe_trunc(T, unsafe_trunc(typeof(signed(zero(T))), x))
-    end
-end

src/utilities.jl

@@ -13,6 +13,8 @@ widen1(::Type{Int128})  = Int128
 widen1(::Type{UInt128}) = UInt128
 widen1(x::Integer) = x % widen1(typeof(x))
 
+signedtype(::Type{T}) where {T <: Integer} = typeof(signed(zero(T)))
+
 const ShortInts = Union{Int8, UInt8, Int16, UInt16}
 const LongInts = Union{Int64, UInt64, Int128, UInt128, BigInt}
 
@@ -34,3 +36,14 @@ significand_bits(::Type{Float32}) = 23
 significand_bits(::Type{Float64}) = 52
 exponent_bias(::Type{Float32}) = 127
 exponent_bias(::Type{Float64}) = 1023
+
+_unsafe_trunc(::Type{T}, x::Integer) where {T} = x % T
+_unsafe_trunc(::Type{T}, x) where {T}          = unsafe_trunc(T, x)
+if !signbit(signed(unsafe_trunc(UInt, -12.345)))
+    # a workaround for ARM (issue #134)
+    function _unsafe_trunc(::Type{T}, x::AbstractFloat) where {T <: Integer}
+        unsafe_trunc(T, unsafe_trunc(signedtype(T), x))
+    end
+    # exclude BigFloat (issue #202)
+    _unsafe_trunc(::Type{T}, x::BigFloat) where {T <: Integer} = unsafe_trunc(T, x)
+end