fix slowness of randn introduced by 84b6aec

base/random.jl

@@ -126,7 +126,7 @@ globalRNG() = GLOBAL_RNG
 
 # rand: a non-specified RNG defaults to GLOBAL_RNG
 
-@inline rand() = rand_close_open(GLOBAL_RNG)
+@inline rand() = rand(GLOBAL_RNG)
 @inline rand(T::Type) = rand(GLOBAL_RNG, T)
 rand(::()) = rand(GLOBAL_RNG, ()) # needed to resolve ambiguity
 rand(dims::Dims) = rand(GLOBAL_RNG, dims)
@@ -137,10 +137,10 @@ rand!(A::AbstractArray) = rand!(GLOBAL_RNG, A)
 
 ## random floating point values
 
-@inline rand(r::AbstractRNG) = rand_close_open(r)
+@inline rand(r::AbstractRNG) = rand(r, Float64)
 
 # MersenneTwister
-rand(r::MersenneTwister, ::Type{Float64}) = rand_close_open(r)
+@inline rand(r::MersenneTwister, ::Type{Float64}) = rand_close_open(r)
 rand{T<:Union(Float16, Float32)}(r::MersenneTwister, ::Type{T}) = convert(T, rand(r, Float64))
 
 ## random integers (MersenneTwister)
@@ -813,6 +813,9 @@ const ziggurat_exp_r      = 7.6971174701310497140446280481
 
 @inline randi(rng::MersenneTwister=GLOBAL_RNG) = reinterpret(Uint64, rand_close1_open2(rng)) & 0x000fffffffffffff
 
+# the @inline'd rand(rng) method makes randmtzig_randn slower
+rand_noinline(rng::MersenneTwister) = rand(rng)
+
 function randmtzig_randn(rng::MersenneTwister=GLOBAL_RNG)
     @inbounds begin
         while true
@@ -824,13 +827,13 @@ function randmtzig_randn(rng::MersenneTwister=GLOBAL_RNG)
                 return x # 99.3% of the time we return here 1st try
             elseif idx == 0
                 while true
-                    xx = -ziggurat_nor_inv_r*log(rand(rng))
-                    yy = -log(rand(rng))
+                    xx = -ziggurat_nor_inv_r*log(rand_noinline(rng))
+                    yy = -log(rand_noinline(rng))
                     if yy+yy > xx*xx
                         return (rabs & 0x100) != 0x000000000 ? -ziggurat_nor_r-xx : ziggurat_nor_r+xx
                     end
                 end
-            elseif (fi[idx] - fi[idx+1])*rand(rng) + fi[idx+1] < exp(-0.5*x*x)
+            elseif (fi[idx] - fi[idx+1])*rand_noinline(rng) + fi[idx+1] < exp(-0.5*x*x)
                 return x # return from the triangular area
             end
         end