Graceful exit for transpose/adjoint on size 0 arrays (#613)

* Graceful exit for transpose/adjoint on size 0 arrays

* Fix for CUDA

* Use length rather than axes

* use isempty

Author: kshyatt

src/host/linalg.jl

@@ -14,6 +14,7 @@ function LinearAlgebra.transpose!(B::AbstractGPUMatrix, A::AbstractGPUVector)
 end
 function LinearAlgebra.adjoint!(B::AbstractGPUVector, A::AbstractGPUMatrix)
     axes(B,1) == axes(A,2) && axes(A,1) == 1:1 || throw(DimensionMismatch("adjoint"))
+    isempty(A) && return B
     @kernel function adjoint_kernel!(B, A)
         idx = @index(Global, Linear)
         @inbounds B[idx] = adjoint(A[1, idx])
@@ -23,6 +24,7 @@ function LinearAlgebra.adjoint!(B::AbstractGPUVector, A::AbstractGPUMatrix)
 end
 function LinearAlgebra.adjoint!(B::AbstractGPUMatrix, A::AbstractGPUVector)
     axes(B,2) == axes(A,1) && axes(B,1) == 1:1 || throw(DimensionMismatch("adjoint"))
+    isempty(A) && return B
     @kernel function adjoint_kernel!(B, A)
         idx = @index(Global, Linear)
         @inbounds B[1, idx] = adjoint(A[idx])
@@ -35,6 +37,8 @@ LinearAlgebra.transpose!(B::AnyGPUArray, A::AnyGPUArray) = transpose_f!(transpos
 LinearAlgebra.adjoint!(B::AnyGPUArray, A::AnyGPUArray) = transpose_f!(adjoint, B, A)
 function transpose_f!(f, B::AnyGPUMatrix{T}, A::AnyGPUMatrix{T}) where T
     axes(B,1) == axes(A,2) && axes(B,2) == axes(A,1) || throw(DimensionMismatch(string(f)))
+    # array with size zero dimension
+    isempty(A) && return B
     @kernel function transpose_kernel!(B, A)
         idx = @index(Global, Cartesian)
         @inbounds B[idx[2], idx[1]] = f(A[idx[1], idx[2]])

test/testsuite/linalg.jl

@@ -4,10 +4,14 @@
         @test compare(adjoint!, AT, rand(Float32, 32, 32), rand(Float32, 32, 32))
         @test compare(adjoint!, AT, rand(Float32, 1, 32), rand(Float32, 32))
         @test compare(adjoint!, AT, rand(Float32, 32), rand(Float32, 1, 32))
+        @test compare(adjoint!, AT, rand(Float32, 32, 0), rand(Float32, 0, 32))
+        @test compare(adjoint!, AT, rand(Float32, 0, 32), rand(Float32, 32, 0))
         @test compare(transpose, AT, rand(Float32, 32, 32))
         @test compare(transpose!, AT, rand(Float32, 32, 32), rand(Float32, 32, 32))
         @test compare(transpose!, AT, rand(Float32, 1, 32), rand(Float32, 32))
         @test compare(transpose!, AT, rand(Float32, 32), rand(Float32, 1, 32))
+        @test compare(transpose!, AT, rand(Float32, 32, 0), rand(Float32, 0, 32))
+        @test compare(transpose!, AT, rand(Float32, 0, 32), rand(Float32, 32, 0))
         @test compare((x,y)->copyto!(x, adjoint(y)), AT, rand(Float32, 32, 32), rand(Float32, 32, 32))
         @test compare((x,y)->copyto!(x, transpose(y)), AT, rand(Float32, 32, 32), rand(Float32, 32, 32))
         @test compare(transpose!, AT, Array{Float32}(undef, 32, 32), rand(Float32, 32, 32))