re PR tree-optimization/45578 (The polyhedron test mdbx is miscompiled with -O2 -ftree-vectorize at revision 163915)

2010-09-08  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/45578
	* tree-ssa-loop-ivopts.c (rewrite_use_nonlinear_expr):
	Be more careful when transfering alignment information to
	the new induction variable.
	(copy_ref_info): Likewise.

	* gfortran.dg/pr45578.f90: New testcase.

From-SVN: r163997

4 files changed, 104 insertions, 11 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 347e0ae..6da2bc4 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,13 @@
 2010-09-08  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/45578
+	* tree-ssa-loop-ivopts.c (rewrite_use_nonlinear_expr):
+	Be more careful when transfering alignment information to
+	the new induction variable.
+	(copy_ref_info): Likewise.
+
+2010-09-08  Richard Guenther  <rguenther@suse.de>
+
 	* tree.h (TYPE_ORIG_SIZE_TYPE): Remove.
 	* c-typeck.c (comptypes_internal): Remove TYPE_ORIG_SIZE_TYPE
 	checks.
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4a8bc50..1f2cb92 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,10 @@
 2010-09-08  Richard Guenther  <rguenther@suse.de>
 
+	PR tree-optimization/45578
+	* gfortran.dg/pr45578.f90: New testcase.
+
+2010-09-08  Richard Guenther  <rguenther@suse.de>
+
 	PR testsuite/45590
 	* gcc.dg/graphite/pr44391.c: Remove -m32 option.
 
diff --git a/gcc/testsuite/gfortran.dg/pr45578.f90 b/gcc/testsuite/gfortran.dg/pr45578.f90
new file mode 100644
index 0000000..da8863d
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/pr45578.f90
@@ -0,0 +1,53 @@
+! { dg-do run }
+!*==CENTCM.spg  processed by SPAG 6.55Dc at 09:26 on 23 Sep 2005
+      SUBROUTINE CENTCM
+      IMPLICIT DOUBLE PRECISION(A-H,O-Z)
+      PARAMETER (NM=16384)
+      PARAMETER (NG=100)
+      PARAMETER (NH=100)
+      PARAMETER (MU=20)
+      PARAMETER (NL=1)
+      PARAMETER (LL=10*NM)
+      PARAMETER (KP=2001,KR=2001,KG=2001)
+      COMMON /LCS   / X0(3,-2:NM) , X(3,-2:NM,5) , XIN(3,-2:NM)
+      COMMON /MOLEC / LPBc(3) , MOLsp , MOLsa , NBX , NBY , NBZ , NPLa ,&
+     &                LPBcsm
+      cm1 = 0.D0
+      cm2 = 0.D0
+      cm3 = 0.D0
+      DO i = 1 , MOLsa
+         cm1 = cm1 + X0(1,i)
+         cm2 = cm2 + X0(2,i)
+         cm3 = cm3 + X0(3,i)
+      ENDDO
+      cm1 = cm1/MOLsa
+      cm2 = cm2/MOLsa
+      cm3 = cm3/MOLsa
+      IF ( (cm1.EQ.0.D0) .AND. (cm2.EQ.0.D0) .AND. (cm3.EQ.0.D0) )      &
+     &     RETURN
+      DO i = 1 , MOLsa
+        X0(1,i) = X0(1,i) - cm1
+        X0(2,i) = X0(2,i) - cm2
+        X0(3,i) = X0(3,i) - cm3
+        XIN(1,i) = XIN(1,i) - cm1
+        XIN(2,i) = XIN(2,i) - cm2
+        XIN(3,i) = XIN(3,i) - cm3
+      ENDDO
+      CONTINUE
+      END
+      PROGRAM test
+      IMPLICIT DOUBLE PRECISION(A-H,O-Z)
+      PARAMETER (NM=16384)
+      PARAMETER (NG=100)
+      PARAMETER (NH=100)
+      PARAMETER (MU=20)
+      PARAMETER (NL=1)
+      PARAMETER (LL=10*NM)
+      PARAMETER (KP=2001,KR=2001,KG=2001)
+      COMMON /LCS   / X0(3,-2:NM) , X(3,-2:NM,5) , XIN(3,-2:NM)
+      COMMON /MOLEC / LPBc(3) , MOLsp , MOLsa , NBX , NBY , NBZ , NPLa ,&
+     &                LPBcsm
+      MOLsa = 10
+      X0 = 1.
+      CALL CENTCM
+      END
diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index a2abc81..432b3f9 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -5863,7 +5863,16 @@ rewrite_use_nonlinear_expr (struct ivopts_data *data,
       comp = force_gimple_operand_gsi (&bsi, comp, true, NULL_TREE,
 				       true, GSI_SAME_STMT);
       if (POINTER_TYPE_P (TREE_TYPE (tgt)))
-	duplicate_ssa_name_ptr_info (comp, SSA_NAME_PTR_INFO (tgt));
+	{
+	  duplicate_ssa_name_ptr_info (comp, SSA_NAME_PTR_INFO (tgt));
+	  /* As this isn't a plain copy we have to reset alignment
+	     information.  */
+	  if (SSA_NAME_PTR_INFO (comp))
+	    {
+	      SSA_NAME_PTR_INFO (comp)->align = BITS_PER_UNIT;
+	      SSA_NAME_PTR_INFO (comp)->misalign = 0;
+	    }
+	}
     }
 
   if (gimple_code (use->stmt) == GIMPLE_PHI)
@@ -5891,26 +5900,44 @@ copy_ref_info (tree new_ref, tree old_ref)
   TREE_SIDE_EFFECTS (new_ref) = TREE_SIDE_EFFECTS (old_ref);
   TREE_THIS_VOLATILE (new_ref) = TREE_THIS_VOLATILE (old_ref);
 
-  if (TREE_CODE (new_ref) == TARGET_MEM_REF)
-    new_ptr_base = TMR_BASE (new_ref);
-  else if (TREE_CODE (new_ref) == MEM_REF)
-    new_ptr_base = TREE_OPERAND (new_ref, 0);
+  new_ptr_base = TREE_OPERAND (new_ref, 0);
 
   /* We can transfer points-to information from an old pointer
      or decl base to the new one.  */
   if (new_ptr_base
       && TREE_CODE (new_ptr_base) == SSA_NAME
-      && POINTER_TYPE_P (TREE_TYPE (new_ptr_base))
       && !SSA_NAME_PTR_INFO (new_ptr_base))
     {
       tree base = get_base_address (old_ref);
       if (!base)
 	;
-      else if ((INDIRECT_REF_P (base)
-		|| TREE_CODE (base) == MEM_REF)
-	       && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME)
-	duplicate_ssa_name_ptr_info
-	  (new_ptr_base, SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)));
+      else if ((TREE_CODE (base) == MEM_REF
+		|| TREE_CODE (base) == TARGET_MEM_REF)
+	       && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME
+	       && SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)))
+	{
+	  struct ptr_info_def *new_pi;
+	  duplicate_ssa_name_ptr_info
+	    (new_ptr_base, SSA_NAME_PTR_INFO (TREE_OPERAND (base, 0)));
+	  new_pi = SSA_NAME_PTR_INFO (new_ptr_base);
+	  /* We have to be careful about transfering alignment information.  */
+	  if (TREE_CODE (old_ref) == MEM_REF
+	      && !(TREE_CODE (new_ref) == TARGET_MEM_REF
+		   && (TMR_INDEX2 (new_ref)
+		       || (TMR_STEP (new_ref)
+			   && (TREE_INT_CST_LOW (TMR_STEP (new_ref))
+			       < new_pi->align)))))
+	    {
+	      new_pi->misalign += double_int_sub (mem_ref_offset (old_ref),
+						  mem_ref_offset (new_ref)).low;
+	      new_pi->misalign &= (new_pi->align - 1);
+	    }
+	  else
+	    {
+	      new_pi->align = BITS_PER_UNIT;
+	      new_pi->misalign = 0;
+	    }
+	}
       else if (TREE_CODE (base) == VAR_DECL
 	       || TREE_CODE (base) == PARM_DECL
 	       || TREE_CODE (base) == RESULT_DECL)