Support lmul!/rmul! when data is not #undef (#467)

* Support lmul!/rmul! when data is not defined

* Check for primitive type

Author: dlfivefifty

Project.toml

@@ -1,6 +1,6 @@
 name = "BandedMatrices"
 uuid = "aae01518-5342-5314-be14-df237901396f"
-version = "1.9.0"
+version = "1.9.1"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"

src/generic/broadcast.jl

@@ -357,6 +357,7 @@ function _banded_broadcast_BandedColumn!(dest, f, src, z)
 end
 
 function _banded_broadcast!(dest::AbstractMatrix, f, (src,x)::Tuple{AbstractMatrix{T},Number}, ::BandedColumns, ::BandedColumns) where T
+    isprimitivetype(T) || return _banded_broadcast!(dest, f, (src, x), BandedLayout(), BandedLayout())
     z = f(zero(T),x)
     iszero(z) || checkbroadcastband(dest, size(src), bandwidths(broadcasted(f, src,x)))
 
@@ -367,6 +368,8 @@ function _banded_broadcast!(dest::AbstractMatrix, f, (src,x)::Tuple{AbstractMatr
 end
 
 function _banded_broadcast!(dest::AbstractMatrix, f, (x, src)::Tuple{Number,AbstractMatrix{T}}, ::BandedColumns, ::BandedColumns) where T
+    isprimitivetype(T) || return _banded_broadcast!(dest, f, (x, src), BandedLayout(), BandedLayout())
+
     z = f(x, zero(T))
     iszero(z) || checkbroadcastband(dest, size(src), bandwidths(broadcasted(f, x,src)))
 
@@ -824,12 +827,14 @@ function _banded_broadcast(f, A::AbstractMatrix{T}, ::BandedColumns) where T
     _BandedMatrix(Bdata_new, axes(A,1), bandwidths(A)...)
 end
 function _banded_broadcast(f, (src,x)::Tuple{AbstractMatrix{T},Number}, ::BandedColumns) where T
+    isprimitivetype(T) || return _banded_broadcast(f, (src,x), BandedLayout())
     iszero(f(zero(T),x)) || return _default_banded_broadcast(broadcasted(f, src,x))
     Bdata = bandeddata(src)
     Bdata_new = reshape(f.(vec(Bdata), x), size(Bdata))
     _BandedMatrix(Bdata_new, axes(src,1), bandwidths(src)...)
 end
 function _banded_broadcast(f, (x, src)::Tuple{Number,AbstractMatrix{T}}, ::BandedColumns) where T
+    isprimitivetype(T) || return _banded_broadcast(f, (x,src), BandedLayout())
     iszero(f(x, zero(T))) || return _default_banded_broadcast(broadcasted(f, x,src))
     Bdata = bandeddata(src)
     Bdata_new = reshape(f.(x, vec(Bdata)), size(Bdata))
@@ -935,12 +940,20 @@ end
 
 
 function _banded_lmul!(α::Number, A::AbstractMatrix, ::BandedColumns)
-    lmul!(α, bandeddata(A))
+    if !isprimitivetype(eltype(A))
+        _banded_lmul!(α, A, BandedLayout()) # avoid undefined
+    else
+        lmul!(α, bandeddata(A))
+    end
     A
 end
 
 function _banded_rmul!(A::AbstractMatrix, α::Number, ::BandedColumns)
-    rmul!(bandeddata(A), α)
+    if !isprimitivetype(eltype(A))
+        _banded_rmul!(A, α, BandedLayout()) # avoid undefined
+    else
+        rmul!(bandeddata(A), α)
+    end
     A
 end
 

test/test_broadcasting.jl

@@ -770,6 +770,19 @@ Random.seed!(0)
         @test_throws BandError B[band(100)] .= 10
         @test_throws BandError B[band(-100)] .= 10
     end
+
+    @testset "BigFloat l/rmul!" begin
+        A = BandedMatrices._BandedMatrix(Matrix{BigFloat}(undef, 3, 5), 5, 1, 1)
+        for j = axes(A,2), k = colsupport(A,j)
+            A[k,j] = 1
+        end
+        B = 2A
+        @test B == A*2
+        lmul!(2, A)
+        @test A == B
+        rmul!(A, 2)
+        @test A == 2B
+    end
 end
 
 end # module