Handle flipsign(Float16) efficiently

armgong · Dec 7, 2015 · c81dccf · c81dccf
1 parent 2b56de1
commit c81dccf
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diff --git a/base/int.jl b/base/int.jl
@@ -34,11 +34,13 @@ for T in (Int8,Int16,Int32,Int64,Int128)
 end
 
 flipsign(x::Signed, y::Signed)  = flipsign(promote(x,y)...)
+flipsign(x::Signed, y::Float16) = flipsign(x, reinterpret(Int16,y))
 flipsign(x::Signed, y::Float32) = flipsign(x, reinterpret(Int32,y))
 flipsign(x::Signed, y::Float64) = flipsign(x, reinterpret(Int64,y))
 flipsign(x::Signed, y::Real)    = flipsign(x, -oftype(x,signbit(y)))
 
 copysign(x::Signed, y::Signed)  = flipsign(x, x$y)
+copysign(x::Signed, y::Float16) = copysign(x, reinterpret(Int16,y))
 copysign(x::Signed, y::Float32) = copysign(x, reinterpret(Int32,y))
 copysign(x::Signed, y::Float64) = copysign(x, reinterpret(Int64,y))
 copysign(x::Signed, y::Real)    = copysign(x, -oftype(x,signbit(y)))

diff --git a/test/int.jl b/test/int.jl
@@ -17,6 +17,12 @@ for y in (4, Float32(4), 4.0, big(4.0))
     @test copysign(-3, y) == 3
 end
 
+for s1 in (-1,+1), s2 in (-1,+1)
+    @test flipsign(Int16(3s1), Float16(3s2)) === Int16(3s1*s2)
+    @test flipsign(Int32(3s1), Float32(3s2)) === Int32(3s1*s2)
+    @test flipsign(Int64(3s1), Float64(3s2)) === Int64(3s1*s2)
+end
+
 @test signed(3) == 3
 @test signed(UInt(3)) == 3
 @test isa(signed(UInt(3)), Int)