LinearAlgebra: replace internal broadcast indexing method by getindex (#54071)

Within the `@inbounds` annotation, these two should be equivalent, so we
may call the public method instead of the internal one. Performance
remains unchanged by this.

Author: jishnub

stdlib/LinearAlgebra/src/structuredbroadcast.jl

@@ -178,7 +178,7 @@ function copyto!(dest::Diagonal, bc::Broadcasted{<:StructuredMatrixStyle})
     axs = axes(dest)
     axes(bc) == axs || Broadcast.throwdm(axes(bc), axs)
     for i in axs[1]
-        dest.diag[i] = @inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i, i))
+        dest.diag[i] = @inbounds bc[CartesianIndex(i, i)]
     end
     return dest
 end
@@ -188,15 +188,15 @@ function copyto!(dest::Bidiagonal, bc::Broadcasted{<:StructuredMatrixStyle})
     axs = axes(dest)
     axes(bc) == axs || Broadcast.throwdm(axes(bc), axs)
     for i in axs[1]
-        dest.dv[i] = @inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i, i))
+        dest.dv[i] = @inbounds bc[CartesianIndex(i, i)]
     end
     if dest.uplo == 'U'
         for i = 1:size(dest, 1)-1
-            dest.ev[i] = @inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i, i+1))
+            dest.ev[i] = @inbounds bc[CartesianIndex(i, i+1)]
         end
     else
         for i = 1:size(dest, 1)-1
-            dest.ev[i] = @inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i+1, i))
+            dest.ev[i] = @inbounds bc[CartesianIndex(i+1, i)]
         end
     end
     return dest
@@ -207,11 +207,11 @@ function copyto!(dest::SymTridiagonal, bc::Broadcasted{<:StructuredMatrixStyle})
     axs = axes(dest)
     axes(bc) == axs || Broadcast.throwdm(axes(bc), axs)
     for i in axs[1]
-        dest.dv[i] = @inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i, i))
+        dest.dv[i] = @inbounds bc[CartesianIndex(i, i)]
     end
     for i = 1:size(dest, 1)-1
-        v = @inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i, i+1))
-        v == (@inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i+1, i))) || throw(ArgumentError(lazy"broadcasted assignment breaks symmetry between locations ($i, $(i+1)) and ($(i+1), $i)"))
+        v = @inbounds bc[CartesianIndex(i, i+1)]
+        v == (@inbounds bc[CartesianIndex(i+1, i)]) || throw(ArgumentError(lazy"broadcasted assignment breaks symmetry between locations ($i, $(i+1)) and ($(i+1), $i)"))
         dest.ev[i] = v
     end
     return dest
@@ -222,11 +222,11 @@ function copyto!(dest::Tridiagonal, bc::Broadcasted{<:StructuredMatrixStyle})
     axs = axes(dest)
     axes(bc) == axs || Broadcast.throwdm(axes(bc), axs)
     for i in axs[1]
-        dest.d[i] = @inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i, i))
+        dest.d[i] = @inbounds bc[CartesianIndex(i, i)]
     end
     for i = 1:size(dest, 1)-1
-        dest.du[i] = @inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i, i+1))
-        dest.dl[i] = @inbounds Broadcast._broadcast_getindex(bc, CartesianIndex(i+1, i))
+        dest.du[i] = @inbounds bc[CartesianIndex(i, i+1)]
+        dest.dl[i] = @inbounds bc[CartesianIndex(i+1, i)]
     end
     return dest
 end
@@ -237,7 +237,7 @@ function copyto!(dest::LowerTriangular, bc::Broadcasted{<:StructuredMatrixStyle}
     axes(bc) == axs || Broadcast.throwdm(axes(bc), axs)
     for j in axs[2]
         for i in j:axs[1][end]
-            @inbounds dest.data[i,j] = Broadcast._broadcast_getindex(bc, CartesianIndex(i, j))
+            @inbounds dest.data[i,j] = bc[CartesianIndex(i, j)]
         end
     end
     return dest
@@ -249,7 +249,7 @@ function copyto!(dest::UpperTriangular, bc::Broadcasted{<:StructuredMatrixStyle}
     axes(bc) == axs || Broadcast.throwdm(axes(bc), axs)
     for j in axs[2]
         for i in 1:j
-            @inbounds dest.data[i,j] = Broadcast._broadcast_getindex(bc, CartesianIndex(i, j))
+            @inbounds dest.data[i,j] = bc[CartesianIndex(i, j)]
         end
     end
     return dest