This should fix PR59822, us creating in valid SSA form when
hoisting a[i_2] out of a loop where i_2 is defined inside the loop.
Bootstrap / regtest running on x86_64-unknown-linux-gnu.
Richard.
2014-01-15 Richard Biener <rguent...@suse.de>
PR tree-optimization/59822
* tree-vect-stmts.c (hoist_defs_of_uses): New function.
(vectorizable_load): Use it to hoist defs of uses of invariant
loads out of the loop.
* g++.dg/torture/pr59822.C: New testcase.
Index: gcc/tree-vect-stmts.c
===================================================================
*** gcc/tree-vect-stmts.c (revision 206624)
--- gcc/tree-vect-stmts.c (working copy)
*************** permute_vec_elements (tree x, tree y, tr
*** 5480,5485 ****
--- 5480,5538 ----
return data_ref;
}
+ /* Hoist the definitions of all SSA uses on STMT out of the loop LOOP,
+ inserting them on the loops preheader edge. Returns true if we
+ were successful in doing so (and thus STMT can be moved then),
+ otherwise returns false. */
+
+ static bool
+ hoist_defs_of_uses (gimple stmt, struct loop *loop)
+ {
+ ssa_op_iter i;
+ tree op;
+ bool any = false;
+
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE)
+ {
+ gimple def_stmt = SSA_NAME_DEF_STMT (op);
+ if (!gimple_nop_p (def_stmt)
+ && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt)))
+ {
+ /* Make sure we don't need to recurse. While we could do
+ so in simple cases when there are more complex use webs
+ we don't have an easy way to preserve stmt order to fulfil
+ dependencies within them. */
+ tree op2;
+ ssa_op_iter i2;
+ FOR_EACH_SSA_TREE_OPERAND (op2, def_stmt, i2, SSA_OP_USE)
+ {
+ gimple def_stmt2 = SSA_NAME_DEF_STMT (op2);
+ if (!gimple_nop_p (def_stmt2)
+ && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt2)))
+ return false;
+ }
+ any = true;
+ }
+ }
+
+ if (!any)
+ return true;
+
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE)
+ {
+ gimple def_stmt = SSA_NAME_DEF_STMT (op);
+ if (!gimple_nop_p (def_stmt)
+ && flow_bb_inside_loop_p (loop, gimple_bb (def_stmt)))
+ {
+ gimple_stmt_iterator gsi = gsi_for_stmt (def_stmt);
+ gsi_remove (&gsi, false);
+ gsi_insert_on_edge_immediate (loop_preheader_edge (loop), def_stmt);
+ }
+ }
+
+ return true;
+ }
+
/* vectorizable_load.
Check if STMT reads a non scalar data-ref (array/pointer/structure) that
*************** vectorizable_load (gimple stmt, gimple_s
*** 6384,6390 ****
/* If we have versioned for aliasing then we are sure
this is a loop invariant load and thus we can insert
it on the preheader edge. */
! if (LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo))
{
if (dump_enabled_p ())
{
--- 6437,6444 ----
/* If we have versioned for aliasing then we are sure
this is a loop invariant load and thus we can insert
it on the preheader edge. */
! if (LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo)
! && hoist_defs_of_uses (stmt, loop))
{
if (dump_enabled_p ())
{
Index: gcc/testsuite/g++.dg/torture/pr59822.C
===================================================================
*** gcc/testsuite/g++.dg/torture/pr59822.C (revision 0)
--- gcc/testsuite/g++.dg/torture/pr59822.C (working copy)
***************
*** 0 ****
--- 1,14 ----
+ // { dg-do compile }
+
+ typedef struct rtvec_def *rtvec;
+ enum machine_mode { VOIDmode };
+ struct rtvec_def { void *elem[1]; };
+ extern void *const_tiny_rtx[2];
+ void
+ ix86_build_const_vector (enum machine_mode mode, bool vect,
+ void *value, rtvec v, int n_elt)
+ {
+ int i;
+ for (i = 1; i < n_elt; ++i)
+ ((v)->elem[i]) = vect ? value : (const_tiny_rtx[(int) (mode)]);
+ }
