On Tue, 28 Feb 2017, Richard Biener wrote:
>
> Bootstrap / regtest running on x86_64-unknown-linux-gnu.
>
> Richard.
The following is what I committed.
Bootstrapped and tested on x86_64-unknown-linux-gnu.
Richard.
2017-02-28 Richard Biener <rguent...@suse.de>
PR tree-optimization/79740
* tree-ssa-sccvn.c (vn_nary_op_insert_into): Allow redundant
inserts.
(visit_nary_op): Insert the nary into the hashtable if we
pattern-matched sth.
* tree-ssa-pre.c (eliminate_insert): Robustify.
* gcc.dg/torture/pr79740.c: New testcase.
Index: gcc/tree-ssa-sccvn.c
===================================================================
*** gcc/tree-ssa-sccvn.c (revision 245772)
--- gcc/tree-ssa-sccvn.c (working copy)
*************** vn_nary_op_insert_into (vn_nary_op_t vno
*** 2820,2825 ****
--- 2820,2834 ----
vno->hashcode = vn_nary_op_compute_hash (vno);
slot = table->find_slot_with_hash (vno, vno->hashcode, INSERT);
+ /* While we do not want to insert things twice it's awkward to
+ avoid it in the case where visit_nary_op pattern-matches stuff
+ and ends up simplifying the replacement to itself. We then
+ get two inserts, one from visit_nary_op and one from
+ vn_nary_build_or_lookup.
+ So allow inserts with the same value number. */
+ if (*slot && (*slot)->result == vno->result)
+ return *slot;
+
gcc_assert (!*slot);
*slot = vno;
*************** visit_nary_op (tree lhs, gassign *stmt)
*** 3544,3550 ****
result = vn_nary_build_or_lookup (NOP_EXPR,
type, ops);
if (result)
! return set_ssa_val_to (lhs, result);
}
else
{
--- 3553,3563 ----
result = vn_nary_build_or_lookup (NOP_EXPR,
type, ops);
if (result)
! {
! bool changed = set_ssa_val_to (lhs, result);
! vn_nary_op_insert_stmt (stmt, result);
! return changed;
! }
}
else
{
*************** visit_nary_op (tree lhs, gassign *stmt)
*** 3555,3561 ****
TREE_TYPE (lhs),
ops);
if (result)
! return set_ssa_val_to (lhs, result);
}
}
}
--- 3568,3578 ----
TREE_TYPE (lhs),
ops);
if (result)
! {
! bool changed = set_ssa_val_to (lhs, result);
! vn_nary_op_insert_stmt (stmt, result);
! return changed;
! }
}
}
}
Index: gcc/tree-ssa-pre.c
===================================================================
*** gcc/tree-ssa-pre.c (revision 245772)
--- gcc/tree-ssa-pre.c (working copy)
*************** eliminate_push_avail (tree op)
*** 4099,4106 ****
static tree
eliminate_insert (gimple_stmt_iterator *gsi, tree val)
{
! gimple *stmt = gimple_seq_first_stmt (VN_INFO (val)->expr);
! if (!is_gimple_assign (stmt)
|| (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt))
&& gimple_assign_rhs_code (stmt) != VIEW_CONVERT_EXPR
&& gimple_assign_rhs_code (stmt) != BIT_FIELD_REF
--- 4099,4110 ----
static tree
eliminate_insert (gimple_stmt_iterator *gsi, tree val)
{
! /* We can insert a sequence with a single assignment only. */
! gimple_seq stmts = VN_INFO (val)->expr;
! if (!gimple_seq_singleton_p (stmts))
! return NULL_TREE;
! gassign *stmt = dyn_cast <gassign *> (gimple_seq_first_stmt (stmts));
! if (!stmt
|| (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt))
&& gimple_assign_rhs_code (stmt) != VIEW_CONVERT_EXPR
&& gimple_assign_rhs_code (stmt) != BIT_FIELD_REF
*************** eliminate_insert (gimple_stmt_iterator *
*** 4116,4123 ****
if (!leader)
return NULL_TREE;
- gimple_seq stmts = NULL;
tree res;
if (gimple_assign_rhs_code (stmt) == BIT_FIELD_REF)
res = gimple_build (&stmts, BIT_FIELD_REF,
TREE_TYPE (val), leader,
--- 4120,4127 ----
if (!leader)
return NULL_TREE;
tree res;
+ stmts = NULL;
if (gimple_assign_rhs_code (stmt) == BIT_FIELD_REF)
res = gimple_build (&stmts, BIT_FIELD_REF,
TREE_TYPE (val), leader,
Index: gcc/testsuite/gcc.dg/torture/pr79740.c
===================================================================
*** gcc/testsuite/gcc.dg/torture/pr79740.c (nonexistent)
--- gcc/testsuite/gcc.dg/torture/pr79740.c (working copy)
***************
*** 0 ****
--- 1,19 ----
+ /* { dg-do compile } */
+
+ int a;
+ short b;
+ short fn1(unsigned short p1) { return p1 << a; }
+
+ int main()
+ {
+ short c;
+ int d = 4;
+ for (; b;)
+ {
+ c = d + 1;
+ fn1(c);
+ d = 0;
+ }
+ d++;
+ return 0;
+ }
