re PR tree-optimization/35972 (load-PRE missed opportunities without SFTs)

2008-08-19  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/35972
	PR tree-optimization/23094
	* tree-ssa-sccvn.h (vn_reference_lookup_pieces): Add maywalk
	parameter.
	* tree-ssa-sccvn.c (copy_reference_ops_from_ref): Properly
	handle MISALIGNED_INDIRECT_REF.
	(get_ref_from_reference_ops): New helper.
	(vn_reference_lookup_pieces): Walk the use-def chain using the
	alias-oracle if requested.
	* tree-ssa-pre.c (phi_translate_1): Do reference lookup with
	walking the use-def chain.
	(compute_avail): But not here.
	(create_component_ref_by_pieces_1): Properly handle
	MISALIGNED_INDIRECT_REF.
	(do_regular_insertion): Handle fully redundant
	expressions after PHI-translation also for SSA_NAME values, not
	only constants.  Correctly use edoubleprime for that.

	* gcc.dg/tree-ssa/ssa-pre-19.c: New testcase.
	* gcc.dg/autopar/reduc-1.c: Move constant initialized arrays to
	global memory.
	* gcc.dg/autopar/reduc-1char.c: Likewise.
	* gcc.dg/autopar/reduc-1short.c: Likewise.
	* gcc.dg/autopar/reduc-2.c: Likewise.
	* gcc.dg/autopar/reduc-2char.c: Likewise.
	* gcc.dg/autopar/reduc-2short.c: Likewise.
	* gcc.dg/autopar/reduc-3.c: Likewise.
	* gcc.dg/tree-ssa/ifc-20040816-1.c: Likewise.
	* gcc.dg/vect/costmodel/i386/costmodel-vect-reduc-1char.c: Likewise.
	* gcc.dg/vect/costmodel/x86_64/costmodel-vect-reduc-1char.c: Likewise.
	* gcc.dg/vect/fast-math-vect-reduc-5.c: Likewise.
	* gcc.dg/vect/fast-math-vect-reduc-7.c: Likewise.
	* gcc.dg/vect/no-trapping-math-2.c: Likewise.
	* gcc.dg/vect/no-trapping-math-vect-111.c: Likewise.
	* gcc.dg/vect/no-trapping-math-vect-ifcvt-11.c: Likewise.
	* gcc.dg/vect/no-trapping-math-vect-ifcvt-12.c: Likewise.
	* gcc.dg/vect/no-trapping-math-vect-ifcvt-13.c: Likewise.
	* gcc.dg/vect/no-trapping-math-vect-ifcvt-14.c: Likewise.
	* gcc.dg/vect/no-trapping-math-vect-ifcvt-15.c: Likewise.
	* gcc.dg/vect/no-vfa-vect-37.c: Likewise.
	* gcc.dg/vect/no-vfa-vect-depend-1.c: Likewise.
	* gcc.dg/vect/pr18400.c: Likewise.
	* gcc.dg/vect/slp-12b.c: Likewise.
	* gcc.dg/vect/slp-14.c: Likewise.
	* gcc.dg/vect/slp-7.c: Likewise.
	* gcc.dg/vect/slp-15.c: Likewise.
	* gcc.dg/vect/slp-16.c: Likewise.
	* gcc.dg/vect/slp-17.c: Likewise.
	* gcc.dg/vect/slp-24.c: Likewise.
	* gcc.dg/vect/slp-28.c: Likewise.
	* gcc.dg/vect/slp-3.c: Likewise.
	* gcc.dg/vect/slp-34.c: Likewise.
	* gcc.dg/vect/slp-6.c: Likewise.
	* gcc.dg/vect/slp-8.c: Likewise.
	* gcc.dg/vect/vect-107.c: Likewise.
	* gcc.dg/vect/vect-108.c: Likewise.
	* gcc.dg/vect/vect-11.c: Likewise.
	* gcc.dg/vect/vect-112.c: Likewise.
	* gcc.dg/vect/vect-115.c: Likewise.
	* gcc.dg/vect/vect-11a.c: Likewise.
	* gcc.dg/vect/vect-34.c: Likewise.
	* gcc.dg/vect/vect-9.c: Likewise.
	* gcc.dg/vect/vect-97.c: Likewise.
	* gcc.dg/vect/vect-align-1.c: Likewise.
	* gcc.dg/vect/vect-float-extend-1.c: Likewise.
	* gcc.dg/vect/vect-floatint-conversion-1.c: Likewise.
	* gcc.dg/vect/vect-ifcvt-16.c: Likewise.
	* gcc.dg/vect/vect-ifcvt-17.c: Likewise.
	* gcc.dg/vect/vect-ifcvt-2.c: Likewise.
	* gcc.dg/vect/vect-ifcvt-3.c: Likewise.
	* gcc.dg/vect/vect-ifcvt-4.c: Likewise.
	* gcc.dg/vect/vect-ifcvt-5.c: Likewise.
	* gcc.dg/vect/vect-ifcvt-6.c: Likewise.
	* gcc.dg/vect/vect-ifcvt-7.c: Likewise.
	* gcc.dg/vect/vect-intfloat-conversion-1.c: Likewise.
	* gcc.dg/vect/vect-intfloat-conversion-2.c: Likewise.
	* gcc.dg/vect/vect-intfloat-conversion-3.c: Likewise.
	* gcc.dg/vect/vect-intfloat-conversion-4a.c: Likewise.
	* gcc.dg/vect/vect-intfloat-conversion-4b.c: Likewise.
	* gcc.dg/vect/vect-multitypes-2.c: Likewise.
	* gcc.dg/vect/vect-multitypes-5.c: Likewise.
	* gcc.dg/vect/vect-reduc-1.c: Likewise.
	* gcc.dg/vect/vect-reduc-1char.c: Likewise.
	* gcc.dg/vect/vect-reduc-1short.c: Likewise.
	* gcc.dg/vect/vect-reduc-2.c: Likewise.
	* gcc.dg/vect/vect-reduc-3.c: Likewise.
	* gcc.dg/vect/vect-shift-1.c: Likewise.
	* gcc.dg/vect/vect-strided-float.c: Likewise.
	* gcc.dg/vect/vect-strided-store-u32-i2.c: Likewise.
	* gcc.dg/vect/wrapv-vect-reduc-2char.c: Likewise.
	* gcc.dg/vect/wrapv-vect-reduc-2short.c: Likewise.
	* gcc.dg/tree-ssa/gen-vect-11.c: Likewise.
	* gcc.dg/tree-ssa/gen-vect-11a.c: Likewise.
	* gcc.dg/tree-ssa/gen-vect-2.c: Likewise.
	* gcc.dg/vect/costmodel/ppc/costmodel-vect-76c.c: Likewise.

From-SVN: r139226

1 files changed, 112 insertions, 2 deletions

diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c
index f502440..26a65f1 100644
--- a/gcc/tree-ssa-sccvn.c
+++ b/gcc/tree-ssa-sccvn.c
@@ -595,11 +595,13 @@ copy_reference_ops_from_ref (tree ref, VEC(vn_reference_op_s, heap) **result)
       switch (temp.opcode)
 	{
 	case ALIGN_INDIRECT_REF:
-	case MISALIGNED_INDIRECT_REF:
 	case INDIRECT_REF:
 	  /* The only operand is the address, which gets its own
 	     vn_reference_op_s structure.  */
 	  break;
+	case MISALIGNED_INDIRECT_REF:
+	  temp.op0 = TREE_OPERAND (ref, 1);
+	  break;
 	case BIT_FIELD_REF:
 	  /* Record bits and position.  */
 	  temp.op0 = TREE_OPERAND (ref, 1);
@@ -676,6 +678,92 @@ copy_reference_ops_from_ref (tree ref, VEC(vn_reference_op_s, heap) **result)
     }
 }
 
+/* Re-create a reference tree from the reference ops OPS.
+   Returns NULL_TREE if the ops were not handled.
+   This routine needs to be kept in sync with copy_reference_ops_from_ref.  */
+
+static tree
+get_ref_from_reference_ops (VEC(vn_reference_op_s, heap) *ops)
+{
+  vn_reference_op_t op;
+  unsigned i;
+  tree ref, *op0_p = &ref;
+
+  for (i = 0; VEC_iterate (vn_reference_op_s, ops, i, op); ++i)
+    {
+      switch (op->opcode)
+	{
+	case CALL_EXPR:
+	  return NULL_TREE;
+
+	case ALIGN_INDIRECT_REF:
+	case INDIRECT_REF:
+	  *op0_p = build1 (op->opcode, op->type, NULL_TREE);
+	  op0_p = &TREE_OPERAND (*op0_p, 0);
+	  break;
+
+	case MISALIGNED_INDIRECT_REF:
+	  *op0_p = build2 (MISALIGNED_INDIRECT_REF, op->type,
+			   NULL_TREE, op->op0);
+	  op0_p = &TREE_OPERAND (*op0_p, 0);
+	  break;
+
+	case BIT_FIELD_REF:
+	  *op0_p = build3 (BIT_FIELD_REF, op->type, NULL_TREE,
+			   op->op0, op->op1);
+	  op0_p = &TREE_OPERAND (*op0_p, 0);
+	  break;
+
+	case COMPONENT_REF:
+	  *op0_p = build3 (COMPONENT_REF, TREE_TYPE (op->op0), NULL_TREE,
+			   op->op0, op->op1);
+	  op0_p = &TREE_OPERAND (*op0_p, 0);
+	  break;
+
+	case ARRAY_RANGE_REF:
+	case ARRAY_REF:
+	  *op0_p = build4 (op->opcode, op->type, NULL_TREE,
+			   op->op0, op->op1, op->op2);
+	  op0_p = &TREE_OPERAND (*op0_p, 0);
+	  break;
+
+	case STRING_CST:
+	case INTEGER_CST:
+	case COMPLEX_CST:
+	case VECTOR_CST:
+	case REAL_CST:
+	case CONSTRUCTOR:
+	case VAR_DECL:
+	case PARM_DECL:
+	case CONST_DECL:
+	case RESULT_DECL:
+	case SSA_NAME:
+	  *op0_p = op->op0;
+	  break;
+
+	case ADDR_EXPR:
+	  if (op->op0 != NULL_TREE)
+	    {
+	      gcc_assert (is_gimple_min_invariant (op->op0));
+	      *op0_p = op->op0;
+	      break;
+	    }
+	  /* Fallthrough.  */
+	case IMAGPART_EXPR:
+	case REALPART_EXPR:
+	case VIEW_CONVERT_EXPR:
+	  *op0_p = build1 (op->opcode, op->type, NULL_TREE);
+	  op0_p = &TREE_OPERAND (*op0_p, 0);
+	  break;
+
+	default:
+	  return NULL_TREE;
+	}
+    }
+
+  return ref;
+}
+
 /* Copy the operations present in load/store/call REF into RESULT, a vector of
    vn_reference_op_s's.  */
 
@@ -895,7 +983,7 @@ vn_reference_lookup_1 (vn_reference_t vr, vn_reference_t *vnresult)
 tree
 vn_reference_lookup_pieces (VEC (tree, gc) *vuses,
 			    VEC (vn_reference_op_s, heap) *operands,
-			    vn_reference_t *vnresult) 
+			    vn_reference_t *vnresult, bool maywalk)
 {
   struct vn_reference_s vr1;
   tree result;
@@ -907,6 +995,28 @@ vn_reference_lookup_pieces (VEC (tree, gc) *vuses,
   vr1.hashcode = vn_reference_compute_hash (&vr1);
   result = vn_reference_lookup_1 (&vr1, vnresult);
 
+  /* If there is a single defining statement for all virtual uses, we can
+     use that, following virtual use-def chains.  */
+  if (!result
+      && maywalk
+      && vr1.vuses
+      && VEC_length (tree, vr1.vuses) >= 1)
+    {
+      tree ref = get_ref_from_reference_ops (operands);
+      gimple def_stmt;
+      if (ref
+	  && (def_stmt = get_def_ref_stmt_vuses (ref, vr1.vuses))
+	  && is_gimple_assign (def_stmt))
+	{
+	  /* We are now at an aliasing definition for the vuses we want to
+	     look up.  Re-do the lookup with the vdefs for this stmt.  */
+	  vdefs_to_vec (def_stmt, &vuses);
+	  vr1.vuses = valueize_vuses (vuses);
+	  vr1.hashcode = vn_reference_compute_hash (&vr1);
+	  result = vn_reference_lookup_1 (&vr1, vnresult);
+	}
+    }
+
   return result;
 }