This fixes an oversight in an earlier patch of mine (SLP of inductions).
Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk.
Richard.
2017-07-25 Richard Biener <rguent...@suse.de>
PR tree-optimization/81529
* tree-vect-stmts.c (process_use): Disregard live induction PHIs
when optimizing backedge uses.
* gfortran.dg/pr81529.f90: New testcase.
Index: gcc/tree-vect-stmts.c
===================================================================
--- gcc/tree-vect-stmts.c (revision 250494)
+++ gcc/tree-vect-stmts.c (working copy)
@@ -581,9 +583,11 @@ process_use (gimple *stmt, tree use, loo
}
/* We are also not interested in uses on loop PHI backedges that are
inductions. Otherwise we'll needlessly vectorize the IV increment
- and cause hybrid SLP for SLP inductions. */
+ and cause hybrid SLP for SLP inductions. Unless the PHI is live
+ of course. */
else if (gimple_code (stmt) == GIMPLE_PHI
&& STMT_VINFO_DEF_TYPE (stmt_vinfo) == vect_induction_def
+ && ! STMT_VINFO_LIVE_P (stmt_vinfo)
&& (PHI_ARG_DEF_FROM_EDGE (stmt, loop_latch_edge (bb->loop_father))
== use))
{
Index: gcc/testsuite/gfortran.dg/pr81529.f90
===================================================================
--- gcc/testsuite/gfortran.dg/pr81529.f90 (nonexistent)
+++ gcc/testsuite/gfortran.dg/pr81529.f90 (working copy)
@@ -0,0 +1,32 @@
+! { dg-do compile }
+! { dg-options "-std=gnu -fno-tree-scev-cprop -Ofast" }
+
+subroutine CalcCgr(C,rmax,ordgr_max)
+ integer, intent(in) :: rmax,ordgr_max
+ double complex :: Zadj(2,2), Zadj2(2,2)
+ double complex, intent(out) :: C(0:rmax,0:rmax,0:rmax)
+ double complex, allocatable :: Cexpgr(:,:,:,:)
+ double complex :: Caux
+ integer :: rmaxB,rmaxExp,r,n0,n1,n2,k,l,i,j,m,n,nn
+
+ rmaxB = 2*rmax
+ rmaxExp = rmaxB
+ allocate(Cexpgr(0:rmaxExp/2,0:rmaxExp,0:rmaxExp,0:ordgr_max))
+
+ rloop: do r=0,rmaxExp/2
+ do n0=r,1,-1
+ do nn=r-n0,0,-1
+ do i=1,2
+ Caux = Caux - Zadj(i,l)
+ end do
+ Cexpgr(n0,0,0,0) = Caux/(2*(nn+1))
+ end do
+ end do
+ do n1=0,r
+ n2 = r-n1
+ if (r.le.rmax) then
+ C(0,n1,n2) = Cexpgr(0,n1,n2,0)
+ end if
+ end do
+ end do rloop
+end subroutine CalcCgr
