[PATCH] Fix followup for PR83963

[Richard Biener]

GRAPHITE has little testing coverage so only SPEC uncovered a latent
issue in scop_detection::harmful_loop_in_region.

Gets us some more testcases.

Bootstrap and regtest running on x86_64-unknown-linux-gnu.

Richard.

2018-01-22  Richard Biener  <rguent...@suse.de>

        PR tree-optimization/83963
        * graphite-scop-detection.c (scop_detection::harmful_loop_in_region):
        Properly terminate dominator walk when crossing the exit edge not
        when visiting its source block.

        * gfortran.dg/graphite/pr83963.f: New testcase.
        * gcc.dg/graphite/pr83963-2.c: Likewise.

Index: gcc/graphite-scop-detection.c
===================================================================
--- gcc/graphite-scop-detection.c       (revision 256947)
+++ gcc/graphite-scop-detection.c       (working copy)
@@ -677,10 +677,10 @@ scop_detection::harmful_loop_in_region (
        if (!stmt_simple_for_scop_p (scop, gsi_stmt (gsi), bb))
          return true;
 
-      if (bb != exit_bb)
-       for (basic_block dom = first_dom_son (CDI_DOMINATORS, bb);
-            dom;
-            dom = next_dom_son (CDI_DOMINATORS, dom))
+      for (basic_block dom = first_dom_son (CDI_DOMINATORS, bb);
+          dom;
+          dom = next_dom_son (CDI_DOMINATORS, dom))
+       if (dom != scop.exit->dest)
          worklist.safe_push (dom);
     }
 
Index: gcc/testsuite/gfortran.dg/graphite/pr83963.f
===================================================================
--- gcc/testsuite/gfortran.dg/graphite/pr83963.f        (nonexistent)
+++ gcc/testsuite/gfortran.dg/graphite/pr83963.f        (working copy)
@@ -0,0 +1,18 @@
+! { dg-do compile }
+! { dg-options "-O -floop-nest-optimize" }
+
+      SUBROUTINE DAVCI(NORB,NCOR,NCI,NA,NB,
+     *    CI,MAXP,MAXW1,
+     *      IHMCON,ISTRB,ISTRP,ISTAR,II)
+      DIMENSION EC(MAXP,MAXP),IWRK1(2*MAXW1)
+         EC(II,II) = 1.0D+00
+         DO 1396 II=1,MAXP
+            DO 1398 JJ=1,II-1
+               EC(II,JJ) = 0.0D+00
+ 1398       CONTINUE
+ 1396    CONTINUE
+      IF (NA.EQ.NB) THEN
+      CALL RINAB0(SI1,SI2,NORB,NCOR,NCI,NA,NB,CI(1,IP),IACON1,IBCON1,
+     *       IWRK1,IHMCON,ISTRB,ISTRP,ISTAR)
+      ENDIF
+      END
Index: gcc/testsuite/gcc.dg/graphite/pr83963-2.c
===================================================================
--- gcc/testsuite/gcc.dg/graphite/pr83963-2.c   (nonexistent)
+++ gcc/testsuite/gcc.dg/graphite/pr83963-2.c   (working copy)
@@ -0,0 +1,26 @@
+/* { dg-do compile } */
+/* { dg-options "-O -floop-nest-optimize" } */
+
+int Chv_countBigEntries (int npivot, int pivotsizes[], int countflag,
+                        double droptol, int nD)
+{
+  double absval ;
+  double *entries ;
+  int count;
+  int ii, jj, kinc, kk, kstart, stride ;
+  for ( ii = 0 ; ii < nD ; ii++ )
+    { 
+      kk = kstart ;  
+      kinc = stride ;
+      for ( jj = 0 ; jj < ii ; jj++ )
+       {
+         absval = __builtin_fabs(entries[kk]) ; 
+         if ( absval >= droptol )
+           count++ ;   
+         kk += kinc ;    
+         kinc -= 2 ; 
+       }
+      kstart-- ;   
+    }
+  return count;
+}