From f90a8ab0705c18b33d4888e7a89c3a03f3f4e25a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Villemot?= <sebastien@dynare.org>
Date: Fri, 4 Jun 2021 12:05:59 +0200
Subject: [PATCH] Fortran MEX: mark array pointers returned by MEX functions as
contiguous
This can make a difference when the return value of those function is directly
passed to a BLAS/LAPACK function.
On the other hand, if the return value is first stored in a pointer variable,
then it seems necessary to explicitly say that this pointer is also contiguous.
---
mex/sources/matlab_mex.F08 | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/mex/sources/matlab_mex.F08 b/mex/sources/matlab_mex.F08
index 755b6d5403..fae9fd5958 100644
--- a/mex/sources/matlab_mex.F08
+++ b/mex/sources/matlab_mex.F08
@@ -23,8 +23,12 @@
! • remove the “use” declarations
! • remove the “value” keywords
! • convert input character arrays to character(kind=c_char, len=*)
+! • Fortran array pointers returned by the glue code must be marked
+! “contiguous” (which is always the case for C arrays). This will help the
+! Fortran compiler better optimize the code (in some cases, this will avoid
+! array copies)
-! Copyright © 2019-2020 Dynare Team
+! Copyright © 2019-2021 Dynare Team
!
! This file is part of Dynare.
!
@@ -281,21 +285,21 @@ contains
#if MX_HAS_INTERLEAVED_COMPLEX
function mxGetDoubles(pm)
type(c_ptr), intent(in) :: pm
- real(real64), dimension(:), pointer :: mxGetDoubles
+ real(real64), dimension(:), pointer, contiguous :: mxGetDoubles
call c_f_pointer(mxGetDoubles_internal(pm), mxGetDoubles, [ mxGetNumberOfElements(pm) ])
end function mxGetDoubles
#endif
function mxGetPr(pm)
type(c_ptr), intent(in) :: pm
- real(real64), dimension(:), pointer :: mxGetPr
+ real(real64), dimension(:), pointer, contiguous :: mxGetPr
call c_f_pointer(mxGetPr_internal(pm), mxGetPr, [ mxGetNumberOfElements(pm) ])
end function mxGetPr
#if MX_HAS_INTERLEAVED_COMPLEX
function mxGetInt32s(pa)
type(c_ptr), intent(in) :: pa
- integer(int32), dimension(:), pointer :: mxGetInt32s
+ integer(int32), dimension(:), pointer, contiguous :: mxGetInt32s
call c_f_pointer(mxGetInt32s_internal(pa), mxGetInt32s, [ mxGetNumberOfElements(pa) ])
end function mxGetInt32s
#endif
@@ -303,20 +307,20 @@ contains
#if MX_HAS_INTERLEAVED_COMPLEX
function mxGetComplexDoubles(pa)
type(c_ptr), intent(in) :: pa
- complex(real64), dimension(:), pointer :: mxGetComplexDoubles
+ complex(real64), dimension(:), pointer, contiguous :: mxGetComplexDoubles
call c_f_pointer(mxGetComplexDoubles_internal(pa), mxGetComplexDoubles, [ mxGetNumberOfElements(pa) ])
end function mxGetComplexDoubles
#else
function mxGetPi(pm)
type(c_ptr), intent(in) :: pm
- real(real64), dimension(:), pointer :: mxGetPi
+ real(real64), dimension(:), pointer, contiguous :: mxGetPi
call c_f_pointer(mxGetPi_internal(pm), mxGetPi, [ mxGetNumberOfElements(pm) ])
end function mxGetPi
#endif
function mxGetLogicals(array_ptr)
type(c_ptr), intent(in) :: array_ptr
- logical(mxLogical), dimension(:), pointer :: mxGetLogicals
+ logical(mxLogical), dimension(:), pointer, contiguous :: mxGetLogicals
call c_f_pointer(mxGetLogicals_internal(array_ptr), mxGetLogicals, [ mxGetNumberOfElements(array_ptr) ])
end function mxGetLogicals
@@ -342,7 +346,7 @@ contains
function mxArrayToString(pm)
type(c_ptr), intent(in) :: pm
character(kind=c_char, len=:), allocatable :: mxArrayToString
- character(kind=c_char), dimension(:), pointer :: chararray
+ character(kind=c_char), dimension(:), pointer, contiguous :: chararray
integer :: i
call c_f_pointer(mxArrayToString_internal(pm), chararray, [ mxGetNumberOfElements(pm) ])
! Convert the character array into a character scalar (of length > 1)
--
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