re PR tree-optimization/68379 (BB vectorization: definition in block 13 follows the use for SSA_NAME)

2015-12-01  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/68379
	* tree-vect-stmts.c (vectorizable_load): For BB vectorization
	always base loads on the first used DR of a group.
	* tree-vect-data-refs.c (vect_slp_analyze_and_verify_node_alignment):
	Compute alignment of the first scalar element unconditionally.

	* gcc.dg/torture/pr68379.c: New testcase.
	* gfortran.dg/pr68379-1.f90: Likewise.
	* gfortran.dg/pr68379-2.f: Likewise.

From-SVN: r231111

7 files changed, 116 insertions, 2 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 79d8d92..8c8718b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,13 @@
 2015-12-01  Richard Biener  <rguenther@suse.de>
 
+	PR tree-optimization/68379
+	* tree-vect-stmts.c (vectorizable_load): For BB vectorization
+	always base loads on the first used DR of a group.
+	* tree-vect-data-refs.c (vect_slp_analyze_and_verify_node_alignment):
+	Compute alignment of the first scalar element unconditionally.
+
+2015-12-01  Richard Biener  <rguenther@suse.de>
+
 	PR middle-end/68590
 	* genmatch.c (struct capture_info): Add match_use_count.
 	(capture_info::walk_match): Increment match_use_count.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 9e9511d..e786fd8 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,10 @@
+2015-12-01  Richard Biener  <rguenther@suse.de>
+
+	PR tree-optimization/68379
+	* gcc.dg/torture/pr68379.c: New testcase.
+	* gfortran.dg/pr68379-1.f90: Likewise.
+	* gfortran.dg/pr68379-2.f: Likewise.
+
 2015-12-01  Christophe Lyon  <christophe.lyon@linaro.org>
 
 	* gcc.dg/pr46032.c: Add dg-require-effective-target fopenmp.
diff --git a/gcc/testsuite/gcc.dg/torture/pr68379.c b/gcc/testsuite/gcc.dg/torture/pr68379.c
new file mode 100644
index 0000000..6a3be7b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr68379.c
@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+
+int a, b[3], c[3][5];
+
+void
+fn1 ()
+{
+  int e;
+  for (a = 2; a >= 0; a--)
+    for (e = 0; e < 4; e++)
+      c[a][e] = b[a];
+}
diff --git a/gcc/testsuite/gfortran.dg/pr68379-1.f90 b/gcc/testsuite/gfortran.dg/pr68379-1.f90
new file mode 100644
index 0000000..2deaca0
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr68379-1.f90
@@ -0,0 +1,35 @@
+! { dg-do compile }
+! { dg-options "-O3" }
+MODULE qs_efield_berry
+  TYPE cp_error_type
+  END TYPE
+  INTEGER, PARAMETER :: dp=8
+  TYPE qs_energy_type
+    REAL(KIND=dp), POINTER :: efield
+  END TYPE
+  TYPE qs_environment_type
+  END TYPE
+  INTERFACE 
+    SUBROUTINE foo(qs_env,energy,error)
+       IMPORT 
+       TYPE(qs_environment_type), POINTER :: qs_env
+       TYPE(cp_error_type)      :: error
+       TYPE(qs_energy_type), POINTER   :: energy
+    END SUBROUTINE
+  END INTERFACE
+CONTAINS
+  SUBROUTINE qs_efield_mo_derivatives()
+    TYPE(qs_environment_type), POINTER :: qs_env
+    TYPE(cp_error_type)  :: error
+    COMPLEX(dp)          ::   zi(3), zphase(3)
+    REAL(dp)             :: ci(3)
+    TYPE(qs_energy_type), POINTER      :: energy
+    CALL foo(qs_env, energy, error)
+    zi = zi * zphase
+    ci = AIMAG(LOG(zi))
+    DO idir=1,3
+       ener_field=ener_field+ci(idir)*fieldfac(idir)
+    END DO
+    energy%efield=ener_field
+  END SUBROUTINE qs_efield_mo_derivatives
+END MODULE qs_efield_berry
diff --git a/gcc/testsuite/gfortran.dg/pr68379-2.f b/gcc/testsuite/gfortran.dg/pr68379-2.f
new file mode 100644
index 0000000..e26520e
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr68379-2.f
@@ -0,0 +1,24 @@
+! { dg-do compile }
+! { dg-additional-options "-Ofast" }
+! { dg-additional-options "-mavx" { target x86_64-*-* i?86-*-* } }
+
+      SUBROUTINE PASSB4 (IDO,L1,CC,CH,WA1,WA2,WA3)
+      IMPLICIT REAL(4) (A-H, O-Z)
+      DIMENSION CC(IDO,4,L1), CH(IDO,L1,4), WA1(*), WA2(*), WA3(*)
+  102 DO 104 K=1,L1
+         DO 103 I=2,IDO,2
+            TI1 = CC(I,1,K)-CC(I,3,K)
+            TI2 = CC(I,1,K)+CC(I,3,K)
+            TI3 = CC(I,2,K)+CC(I,4,K)
+            TR2 = CC(I-1,1,K)+CC(I-1,3,K)
+            TI4 = CC(I-1,2,K)-CC(I-1,4,K)
+            TR3 = CC(I-1,2,K)+CC(I-1,4,K)
+            CH(I-1,K,1) = TR2+TR3
+            CH(I,K,1) = TI2+TI3
+            CI4 = TI1-TI4
+            CH(I-1,K,4) = CI4
+            CH(I,K,4) = CI4
+  103    CONTINUE
+  104 CONTINUE
+      RETURN
+      END
diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c
index 7962e36..b59b40c 100644
--- a/gcc/tree-vect-data-refs.c
+++ b/gcc/tree-vect-data-refs.c
@@ -2102,11 +2102,16 @@ vect_slp_analyze_and_verify_node_alignment (slp_tree node)
      the node is permuted in which case we start from the first
      element in the group.  */
   gimple *first_stmt = SLP_TREE_SCALAR_STMTS (node)[0];
+  data_reference_p first_dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt));
   if (SLP_TREE_LOAD_PERMUTATION (node).exists ())
     first_stmt = GROUP_FIRST_ELEMENT (vinfo_for_stmt (first_stmt));
 
   data_reference_p dr = STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt));
   if (! vect_compute_data_ref_alignment (dr)
+      /* For creating the data-ref pointer we need alignment of the
+	 first element anyway.  */
+      || (dr != first_dr
+	  && ! vect_compute_data_ref_alignment (first_dr))
       || ! verify_data_ref_alignment (dr))
     {
       if (dump_enabled_p ())
diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c
index 5bb2289..db46eec 100644
--- a/gcc/tree-vect-stmts.c
+++ b/gcc/tree-vect-stmts.c
@@ -6148,6 +6148,7 @@ vectorizable_load (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt,
   bool grouped_load = false;
   bool load_lanes_p = false;
   gimple *first_stmt;
+  gimple *first_stmt_for_drptr = NULL;
   bool inv_p;
   bool negative = false;
   bool compute_in_loop = false;
@@ -6751,10 +6752,14 @@ vectorizable_load (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt,
   if (grouped_load)
     {
       first_stmt = GROUP_FIRST_ELEMENT (stmt_info);
-      /* For BB vectorization we directly vectorize a subchain
+      /* For SLP vectorization we directly vectorize a subchain
          without permutation.  */
       if (slp && ! SLP_TREE_LOAD_PERMUTATION (slp_node).exists ())
-        first_stmt = SLP_TREE_SCALAR_STMTS (slp_node)[0];
+	first_stmt = SLP_TREE_SCALAR_STMTS (slp_node)[0];
+      /* For BB vectorization always use the first stmt to base
+	 the data ref pointer on.  */
+      if (bb_vinfo)
+	first_stmt_for_drptr = SLP_TREE_SCALAR_STMTS (slp_node)[0];
 
       /* Check if the chain of loads is already vectorized.  */
       if (STMT_VINFO_VEC_STMT (vinfo_for_stmt (first_stmt))
@@ -6966,6 +6971,24 @@ vectorizable_load (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt,
 					      (DR_REF (first_dr)), 0);
 	      inv_p = false;
 	    }
+	  else if (first_stmt_for_drptr
+		   && first_stmt != first_stmt_for_drptr)
+	    {
+	      dataref_ptr
+		= vect_create_data_ref_ptr (first_stmt_for_drptr, aggr_type,
+					    at_loop, offset, &dummy, gsi,
+					    &ptr_incr, simd_lane_access_p,
+					    &inv_p, byte_offset);
+	      /* Adjust the pointer by the difference to first_stmt.  */
+	      data_reference_p ptrdr
+		= STMT_VINFO_DATA_REF (vinfo_for_stmt (first_stmt_for_drptr));
+	      tree diff = fold_convert (sizetype,
+					size_binop (MINUS_EXPR,
+						    DR_INIT (first_dr),
+						    DR_INIT (ptrdr)));
+	      dataref_ptr = bump_vector_ptr (dataref_ptr, ptr_incr, gsi,
+					     stmt, diff);
+	    }
 	  else
 	    dataref_ptr
 	      = vect_create_data_ref_ptr (first_stmt, aggr_type, at_loop,