When making COND_EXPR/VEC_COND_EXPR a gimple ternary op I forgot
to update ternary handling in gimple_fold_stmt_to_constant_1 to also
valueize and fold the embedded comparison. Done so. This also
adjusts SCCVN to accept a SSA name result from that folder, when
simplifying A > 1 ? 2 : C to C, which is certainly useful
(observed with a testcase which triggers vector lowering).
Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
Richard.
2011-10-05 Richard Guenther <rguent...@suse.de>
* gimple-fold.c (gimple_fold_stmt_to_constant_1): For
ternary ops with an embedded expression valueize and fold
that as well.
* tree-ssa-sccvn.c (try_to_simplify): Also allow SSA name
results from gimple_fold_stmt_to_constant_1.
Index: gcc/gimple-fold.c
===================================================================
*** gcc/gimple-fold.c (revision 179540)
--- gcc/gimple-fold.c (working copy)
*************** gimple_fold_stmt_to_constant_1 (gimple s
*** 2569,2574 ****
--- 2569,2587 ----
tree op1 = (*valueize) (gimple_assign_rhs2 (stmt));
tree op2 = (*valueize) (gimple_assign_rhs3 (stmt));
+ /* Fold embedded expressions in ternary codes. */
+ if ((subcode == COND_EXPR
+ || subcode == VEC_COND_EXPR)
+ && COMPARISON_CLASS_P (op0))
+ {
+ tree op00 = (*valueize) (TREE_OPERAND (op0, 0));
+ tree op01 = (*valueize) (TREE_OPERAND (op0, 1));
+ tree tem = fold_binary_loc (loc, TREE_CODE (op0),
+ TREE_TYPE (op0), op00, op01);
+ if (tem)
+ op0 = tem;
+ }
+
return fold_ternary_loc (loc, subcode,
gimple_expr_type (stmt), op0, op1, op2);
}
Index: gcc/tree-ssa-sccvn.c
===================================================================
*** gcc/tree-ssa-sccvn.c (revision 179539)
--- gcc/tree-ssa-sccvn.c (working copy)
*************** simplify_unary_expression (gimple stmt)
*** 2967,2993 ****
static tree
try_to_simplify (gimple stmt)
{
tree tem;
/* For stores we can end up simplifying a SSA_NAME rhs. Just return
in this case, there is no point in doing extra work. */
! if (gimple_assign_copy_p (stmt)
! && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME)
return NULL_TREE;
/* First try constant folding based on our current lattice. */
! tem = gimple_fold_stmt_to_constant (stmt, vn_valueize);
! if (tem)
return tem;
/* If that didn't work try combining multiple statements. */
! switch (TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)))
{
case tcc_reference:
! /* Fallthrough for some codes that can operate on registers. */
! if (!(TREE_CODE (gimple_assign_rhs1 (stmt)) == REALPART_EXPR
! || TREE_CODE (gimple_assign_rhs1 (stmt)) == IMAGPART_EXPR
! || TREE_CODE (gimple_assign_rhs1 (stmt)) == VIEW_CONVERT_EXPR))
break;
/* We could do a little more with unary ops, if they expand
into binary ops, but it's debatable whether it is worth it. */
--- 2967,2995 ----
static tree
try_to_simplify (gimple stmt)
{
+ enum tree_code code = gimple_assign_rhs_code (stmt);
tree tem;
/* For stores we can end up simplifying a SSA_NAME rhs. Just return
in this case, there is no point in doing extra work. */
! if (code == SSA_NAME)
return NULL_TREE;
/* First try constant folding based on our current lattice. */
! tem = gimple_fold_stmt_to_constant_1 (stmt, vn_valueize);
! if (tem
! && (TREE_CODE (tem) == SSA_NAME
! || is_gimple_min_invariant (tem)))
return tem;
/* If that didn't work try combining multiple statements. */
! switch (TREE_CODE_CLASS (code))
{
case tcc_reference:
! /* Fallthrough for some unary codes that can operate on registers. */
! if (!(code == REALPART_EXPR
! || code == IMAGPART_EXPR
! || code == VIEW_CONVERT_EXPR))
break;
/* We could do a little more with unary ops, if they expand
into binary ops, but it's debatable whether it is worth it. */
