Tested on x86_64-unknown-linux-gnu, applied. Richard.
2017-12-01 Richard Biener <rguent...@suse.de> * gfortran.dg/pr81303.f: New testcase. Index: gcc/testsuite/gfortran.dg/pr81303.f =================================================================== --- gcc/testsuite/gfortran.dg/pr81303.f (nonexistent) +++ gcc/testsuite/gfortran.dg/pr81303.f (working copy) @@ -0,0 +1,44 @@ +! { dg-do compile } +! { dg-options "-O3 -floop-interchange -fdump-tree-linterchange-details" } + + subroutine mat_times_vec(y,x,a,axp,ayp,azp,axm,aym,azm, + $ nb,nx,ny,nz) + implicit none + integer nb,nx,ny,nz,i,j,k,m,l,kit,im1,ip1,jm1,jp1,km1,kp1 + + real*8 y(nb,nx,ny,nz),x(nb,nx,ny,nz) + + real*8 a(nb,nb,nx,ny,nz), + 1 axp(nb,nb,nx,ny,nz),ayp(nb,nb,nx,ny,nz),azp(nb,nb,nx,ny,nz), + 2 axm(nb,nb,nx,ny,nz),aym(nb,nb,nx,ny,nz),azm(nb,nb,nx,ny,nz) + + + do k=1,nz + km1=mod(k+nz-2,nz)+1 + kp1=mod(k,nz)+1 + do j=1,ny + jm1=mod(j+ny-2,ny)+1 + jp1=mod(j,ny)+1 + do i=1,nx + im1=mod(i+nx-2,nx)+1 + ip1=mod(i,nx)+1 + do l=1,nb + y(l,i,j,k)=0.0d0 + do m=1,nb + y(l,i,j,k)=y(l,i,j,k)+ + 1 a(l,m,i,j,k)*x(m,i,j,k)+ + 2 axp(l,m,i,j,k)*x(m,ip1,j,k)+ + 3 ayp(l,m,i,j,k)*x(m,i,jp1,k)+ + 4 azp(l,m,i,j,k)*x(m,i,j,kp1)+ + 5 axm(l,m,i,j,k)*x(m,im1,j,k)+ + 6 aym(l,m,i,j,k)*x(m,i,jm1,k)+ + 7 azm(l,m,i,j,k)*x(m,i,j,km1) + enddo + enddo + enddo + enddo + enddo + return + end + +! { dg-final { scan-tree-dump-times "is interchanged" 1 "linterchange" } }