Support mul! for real plans in tests

Author: gaurav-arya

test/TestPlans.jl

@@ -1,6 +1,7 @@
 module TestPlans
 
 import AbstractFFTs
+import LinearAlgebra.mul!
 using AbstractFFTs: Plan
 
 mutable struct TestPlan{T,N} <: Plan{T}
@@ -193,6 +194,29 @@ end
 
 to_real!(x::AbstractArray) = map!(real, x, x)
 
+function mul!(y::AbstractArray, p::TestRPlan, x::AbstractArray)
+    # compute DFT
+    dft!(y, x, p.region, -1)
+
+    # we clean the output a bit to make sure that we return real values
+    # whenever the output is mathematically guaranteed to be a real number
+    firstdim = first(p.region)::Int
+    d = size(x, firstdim)
+    firstdim_size = d ÷ 2 + 1
+    to_real!(selectdim(y, firstdim, 1))
+    if iseven(d)
+        to_real!(selectdim(y, firstdim, firstdim_size))
+    end
+
+    return y
+end
+
+function mul!(y::AbstractArray, p::InverseTestRPlan, x::AbstractArray)
+    # compute DFT
+    real_invdft!(y, x, p.region)
+    return y
+end
+
 function Base.:*(p::TestRPlan, x::AbstractArray)
     size(p) == size(x) || error("array and plan are not consistent")
 
@@ -205,16 +229,7 @@ function Base.:*(p::TestRPlan, x::AbstractArray)
     y = similar(x, T, sz)
 
     # compute DFT
-    dft!(y, x, p.region, -1)
-
-    # we clean the output a bit to make sure that we return real values
-    # whenever the output is mathematically guaranteed to be a real number
-    to_real!(selectdim(y, firstdim, 1))
-    if iseven(d)
-        to_real!(selectdim(y, firstdim, firstdim_size))
-    end
-
-    return y
+    mul!(y, p, x)
 end
 
 function Base.:*(p::InverseTestRPlan, x::AbstractArray)
@@ -227,9 +242,7 @@ function Base.:*(p::InverseTestRPlan, x::AbstractArray)
     y = similar(x, real(float(eltype(x))), sz)
 
     # compute DFT
-    real_invdft!(y, x, p.region)
-
-    return y
+    mul!(y, p, x)
 end
 
 end