simplify workspace

Author: jalvesz

src/stdlib_linalg_iterative_solvers.fypp

@@ -19,10 +19,8 @@ module stdlib_linalg_iterative_solvers
     #:endfor
 
     #:for k, t, s in R_KINDS_TYPES
-    type, abstract, public :: solver_workspace_${s}$
-    end type
-    type, public, extends(solver_workspace_${s}$) :: cg_workspace_${s}$
-        ${t}$, allocatable :: r(:), p(:), Ap(:)
+    type, public :: solver_workspace_${s}$
+        ${t}$, allocatable :: tmp(:,:)
     end type 
 
     #:endfor
@@ -49,7 +47,7 @@ module stdlib_linalg_iterative_solvers
             ${t}$, intent(in) :: b(:), tol
             ${t}$, intent(inout) :: x(:)
             integer, intent(in) :: maxiter
-            type(cg_workspace_${s}$), intent(inout) :: workspace
+            type(solver_workspace_${s}$), intent(inout) :: workspace
         end subroutine
         #:endfor
     end interface
@@ -67,7 +65,7 @@ module stdlib_linalg_iterative_solvers
             ${t}$, intent(in) :: b(:), tol
             ${t}$, intent(inout) :: x(:)
             integer, intent(in), optional :: maxiter
-            type(cg_workspace_${s}$), optional, intent(inout), target :: workspace
+            type(solver_workspace_${s}$), optional, intent(inout), target :: workspace
         end subroutine
         #:endfor
         #:endfor

src/stdlib_linalg_iterative_solvers_cg.fypp

@@ -20,14 +20,14 @@ contains
         ${t}$, intent(in) :: b(:), tol
         ${t}$, intent(inout) :: x(:)
         integer, intent(in) :: maxiter
-        type(cg_workspace_${s}$), intent(inout) :: workspace
+        type(solver_workspace_${s}$), intent(inout) :: workspace
         !-------------------------
         integer :: iter
         ${t}$ :: rtr, rtrold, alpha, beta, norm0_sq
         !-------------------------
-        associate(  p => workspace%p, &
-                    r => workspace%r, &
-                    Ap => workspace%Ap)
+        associate(  p  => workspace%tmp(:,1), &
+                    r  => workspace%tmp(:,2), &
+                    Ap => workspace%tmp(:,3))
             x = zero_${s}$
             rtr = A%inner_product(r, r)
             norm0_sq = A%inner_product(b, b)
@@ -60,10 +60,10 @@ contains
         ${t}$, intent(in) :: b(:), tol
         ${t}$, intent(inout) :: x(:)
         integer, intent(in), optional :: maxiter
-        type(cg_workspace_${s}$), optional, intent(inout), target :: workspace
+        type(solver_workspace_${s}$), optional, intent(inout), target :: workspace
         !-------------------------
         type(linop_${s}$) :: op
-        type(cg_workspace_${s}$), pointer :: workspace_
+        type(solver_workspace_${s}$), pointer :: workspace_
         integer :: n, maxiter_
         !-------------------------
         n = size(b)
@@ -75,10 +75,7 @@ contains
         if(present(workspace)) then
             workspace_ => workspace
         else
-            allocate( workspace_%r(n), &
-                      workspace_%p(n), &
-                      workspace_%Ap(n))
-            
+            allocate( workspace_%tmp(n,3) )
         end if
         call solve_cg_generic(op,b,x,tol,maxiter_,workspace_)
         contains