re PR fortran/84270 (optimization bug with assumed size array argument)

2018-02-17  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/84270
	* frontend-passes (scalarized_expr):  If the expression
	is an assumed size array, leave in the last reference
	and pass AR_SECTION instead of AR_FULL to gfc_resolve
	in order to avoid an error.

2018-02-17  Thomas Koenig  <tkoenig@gcc.gnu.org>

	PR fortran/84270
	* gfortran.dg/inline_matmul_22.f90: New test.

From-SVN: r257783

gcc/fortran/ChangeLog

+2018-02-17  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	PR fortran/84270
+	* frontend-passes (scalarized_expr):  If the expression
+	is an assumed size array, leave in the last reference
+	and pass AR_SECTION instead of AR_FULL to gfc_resolve
+	in order to avoid an error.
+
 2018-02-17  Paul Thomas  <pault@gcc.gnu.org>
 
 	PR fortran/84115

gcc/fortran/frontend-passes.c

@@ -3567,10 +3567,26 @@ scalarized_expr (gfc_expr *e_in, gfc_expr **index, int count_index)
 			 is the lbound of a full ref.  */
 		      int j;
 		      gfc_array_ref *ar;
+		      int to;
 
 		      ar = &ref->u.ar;
-		      ar->type = AR_FULL;
-		      for (j = 0; j < ar->dimen; j++)
+
+		      /* For assumed size, we need to keep around the final
+			 reference in order not to get an error on resolution
+			 below, and we cannot use AR_FULL.  */
+			 
+		      if (ar->as->type == AS_ASSUMED_SIZE)
+			{
+			  ar->type = AR_SECTION;
+			  to = ar->dimen - 1;
+			}
+		      else
+			{
+			  to = ar->dimen;
+			  ar->type = AR_FULL;
+			}
+
+		      for (j = 0; j < to; j++)
 			{
 			  gfc_free_expr (ar->start[j]);
 			  ar->start[j] = NULL;

gcc/testsuite/ChangeLog

 2018-02-17  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
+	PR fortran/84270
+	* gfortran.dg/inline_matmul_22.f90: New test.
+
+2018-02-17  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
 	PR fortran/84381
 	* gfortran.dg/abort_shoulfail.f90: New test.
 	* gcc.target/powerpc/ppc-fortran/pr80108-1.f90: Replace CALL ABORT

gcc/testsuite/gfortran.dg/inline_matmul_22.f90

+! { dg-do compile }
+! { dg-additional-options "-ffrontend-optimize" }
+! PR 84270 - this used to be rejected.
+! Test case by Michael Weinert
+
+module fp_precision
+
+   integer, parameter   :: fp = selected_real_kind(13)
+
+end module fp_precision
+
+      subroutine lhcal(nrot,orth,ngpts,vgauss,vr_0)
+
+      use fp_precision  ! floating point precision
+
+      implicit none
+
+!--->    rotation matrices and rotations (input)
+      integer,          intent(in)  :: nrot
+!     real(kind=fp),    intent(in)  :: orth(3,3,nrot)  ! fine at all -O
+      real(kind=fp),    intent(in)  :: orth(3,3,*)
+
+!--->    gaussian integration points
+      integer,          intent(in)  :: ngpts
+      real(kind=fp),    intent(in)  :: vgauss(3,*)
+
+!--->    output results
+      real(kind=fp),    intent(out) :: vr_0(3)
+
+      real(kind=fp)     :: v(3),vr(3)
+      integer           :: n,nn
+
+      vr_0 = 0
+      do nn=1,ngpts
+         v(:) = vgauss(:,nn)
+!--->    apply rotations
+         do n=2,nrot
+            vr = matmul( orth(:,:,n), v )
+            vr_0 = vr_0 + vr
+         enddo
+      enddo
+
+      return
+      end subroutine lhcal