re PR middle-end/51285 (internal compiler error: in check_loop_closed_ssa_use, at tree-ssa-loop-manip.c)

        PR middle-end/51285
        * tree-vect-loop.c (vect_create_epilog_for_reduction): Create
        exit phi nodes for outer loop in case of double reduction.

From-SVN: r181990

4 files changed, 79 insertions, 3 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 222ff20..8a763f3 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2011-12-04  Ira Rosen  <ira.rosen@linaro.org>
+
+	PR middle-end/51285
+	* tree-vect-loop.c (vect_create_epilog_for_reduction): Create exit
+	phi nodes for outer loop in case of double reduction.
+
 2011-12-04  Jérémie Detrey  <Jeremie.Detrey@loria.fr>
 
 	PR target/51393
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7b048bf..ab8534e 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2011-12-04  Ira Rosen  <ira.rosen@linaro.org>
+
+	PR middle-end/51285
+	* gfortran.dg/vect/pr51285.f90: New test.
+
 2011-12-04  Uros Bizjak  <ubizjak@gmail.com>
 	    Jérémie Detrey  <Jeremie.Detrey@loria.fr>
 
diff --git a/gcc/testsuite/gfortran.dg/vect/pr51285.f90 b/gcc/testsuite/gfortran.dg/vect/pr51285.f90
new file mode 100644
index 0000000..92907f3
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/vect/pr51285.f90
@@ -0,0 +1,36 @@
+! { dg-do compile }
+
+   SUBROUTINE smm_dnn_4_10_10_1_1_2_1(A,B,C)
+      REAL   :: C(4,10), B(10,10), A(4,10)
+      DO j=           1 ,          10 ,           2
+      DO i=           1 ,           4 ,           1
+      DO l=           1 ,          10 ,           1
+        C(i+0,j+0)=C(i+0,j+0)+A(i+0,l+0)*B(l+0,j+0)
+        C(i+0,j+1)=C(i+0,j+1)+A(i+0,l+0)*B(l+0,j+1)
+      ENDDO
+      ENDDO
+      ENDDO
+    END SUBROUTINE
+   SUBROUTINE smm_dnn_4_10_10_6_4_1_1(A,B,C)
+      REAL   :: C(4,10), B(10,10), A(4,10)
+      DO l=           1 ,          10 ,           1
+      DO j=           1 ,          10 ,           1
+        C(i+0,j+0)=C(i+0,j+0)+A(i+0,l+0)*B(l+0,j+0)
+      ENDDO
+      ENDDO
+    END SUBROUTINE
+ SUBROUTINE S(A,B,C)
+    INTEGER :: Nmin=2,Niter=100
+    REAL, DIMENSION(:,:), ALLOCATABLE   :: A,B,C
+    DO imin=1,Nmin
+     DO i=1,Niter
+       CALL smm_dnn_4_10_10_1_1_2_1(A,B,C)
+     ENDDO
+     DO i=1,Niter
+       CALL smm_dnn_4_10_10_6_4_1_1(A,B,C)
+     ENDDO
+     CALL foo()
+    ENDDO
+ END SUBROUTINE
+
+! { dg-final { cleanup-tree-dump "vect" } }
diff --git a/gcc/tree-vect-loop.c b/gcc/tree-vect-loop.c
index fb15d6e..30d45c4 100644
--- a/gcc/tree-vect-loop.c
+++ b/gcc/tree-vect-loop.c
@@ -3462,6 +3462,7 @@ vect_create_epilog_for_reduction (VEC (tree, heap) *vect_defs, gimple stmt,
   gimple use_stmt, orig_stmt, reduction_phi = NULL;
   bool nested_in_vect_loop = false;
   VEC (gimple, heap) *new_phis = NULL;
+  VEC (gimple, heap) *inner_phis = NULL;
   enum vect_def_type dt = vect_unknown_def_type;
   int j, i;
   VEC (tree, heap) *scalar_results = NULL;
@@ -3470,6 +3471,7 @@ vect_create_epilog_for_reduction (VEC (tree, heap) *vect_defs, gimple stmt,
   VEC (gimple, heap) *phis;
   bool slp_reduc = false;
   tree new_phi_result;
+  gimple inner_phi = NULL;
 
   if (slp_node)
     group_size = VEC_length (gimple, SLP_TREE_SCALAR_STMTS (slp_node)); 
@@ -3626,11 +3628,36 @@ vect_create_epilog_for_reduction (VEC (tree, heap) *vect_defs, gimple stmt,
     }
 
   /* The epilogue is created for the outer-loop, i.e., for the loop being
-     vectorized.  */
+     vectorized.  Create exit phis for the outer loop.  */
   if (double_reduc)
     {
       loop = outer_loop;
       exit_bb = single_exit (loop)->dest;
+      inner_phis = VEC_alloc (gimple, heap, VEC_length (tree, vect_defs));
+      FOR_EACH_VEC_ELT (gimple, new_phis, i, phi)
+	{
+	  gimple outer_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (phi)),
+					      exit_bb);
+	  SET_PHI_ARG_DEF (outer_phi, single_exit (loop)->dest_idx,
+			   PHI_RESULT (phi));
+	  set_vinfo_for_stmt (outer_phi, new_stmt_vec_info (outer_phi,
+							    loop_vinfo, NULL));
+	  VEC_quick_push (gimple, inner_phis, phi);
+	  VEC_replace (gimple, new_phis, i, outer_phi);
+	  prev_phi_info = vinfo_for_stmt (outer_phi);
+          while (STMT_VINFO_RELATED_STMT (vinfo_for_stmt (phi)))
+            {
+	      phi = STMT_VINFO_RELATED_STMT (vinfo_for_stmt (phi));
+	      outer_phi = create_phi_node (SSA_NAME_VAR (PHI_RESULT (phi)),
+					   exit_bb);
+	      SET_PHI_ARG_DEF (outer_phi, single_exit (loop)->dest_idx,
+			       PHI_RESULT (phi));
+	      set_vinfo_for_stmt (outer_phi, new_stmt_vec_info (outer_phi,
+							loop_vinfo, NULL));
+	      STMT_VINFO_RELATED_STMT (prev_phi_info) = outer_phi;
+	      prev_phi_info = vinfo_for_stmt (outer_phi);
+	    }
+	}
     }
 
   exit_gsi = gsi_after_labels (exit_bb);
@@ -4040,6 +4067,8 @@ vect_finalize_reduction:
         {
           epilog_stmt = VEC_index (gimple, new_phis, k / ratio);
           reduction_phi = VEC_index (gimple, reduction_phis, k / ratio);
+	  if (double_reduc)
+	    inner_phi = VEC_index (gimple, inner_phis, k / ratio);
         }
 
       if (slp_reduc)
@@ -4123,7 +4152,7 @@ vect_finalize_reduction:
                      vs1 was created previously in this function by a call to
                        vect_get_vec_def_for_operand and is stored in
                        vec_initial_def;
-                     vs2 is defined by EPILOG_STMT, the vectorized EXIT_PHI;
+                     vs2 is defined by INNER_PHI, the vectorized EXIT_PHI;
                      vs0 is created here.  */
 
                   /* Create vector phi node.  */
@@ -4144,7 +4173,7 @@ vect_finalize_reduction:
                   add_phi_arg (vect_phi, vect_phi_init,
                                loop_preheader_edge (outer_loop),
                                UNKNOWN_LOCATION);
-                  add_phi_arg (vect_phi, PHI_RESULT (epilog_stmt),
+                  add_phi_arg (vect_phi, PHI_RESULT (inner_phi),
                                loop_latch_edge (outer_loop), UNKNOWN_LOCATION);
                   if (vect_print_dump_info (REPORT_DETAILS))
                     {