This fixes PR51363 - we can simplify the condition in DOM to not
use gimple_rhs_has_side_effects (a weird function which still contains
the checking code I removed from gimple_has_side_effects - the
LHS is never a side-effect considered by gimple_has_side_effects
anyway, side-effects are things not explicitely encoded in the
stmt itself).
Bootstrap & regtest running on x86_64-unknown-linux-gnu.
Richard.
2011-12-05 Richard Guenther <rguent...@suse.de>
PR tree-optimization/51363
* gimple.c (gimple_rhs_has_side_effects): Remove.
* gimple.h (gimple_rhs_has_side_effects): Likewise.
* tree-ssa-dom.c (optimize_stmt): Simplify conditional.
Index: gcc/gimple.c
===================================================================
*** gcc/gimple.c (revision 182010)
--- gcc/gimple.c (working copy)
*************** gimple_has_side_effects (const_gimple s)
*** 2484,2552 ****
return false;
}
- /* Return true if the RHS of statement S has side effects.
- We may use it to determine if it is admissable to replace
- an assignment or call with a copy of a previously-computed
- value. In such cases, side-effects due to the LHS are
- preserved. */
-
- bool
- gimple_rhs_has_side_effects (const_gimple s)
- {
- unsigned i;
-
- if (is_gimple_call (s))
- {
- unsigned nargs = gimple_call_num_args (s);
- tree fn;
-
- if (!(gimple_call_flags (s) & (ECF_CONST | ECF_PURE)))
- return true;
-
- /* We cannot use gimple_has_volatile_ops here,
- because we must ignore a volatile LHS. */
- fn = gimple_call_fn (s);
- if (fn && (TREE_SIDE_EFFECTS (fn) || TREE_THIS_VOLATILE (fn)))
- {
- gcc_assert (gimple_has_volatile_ops (s));
- return true;
- }
-
- for (i = 0; i < nargs; i++)
- if (TREE_SIDE_EFFECTS (gimple_call_arg (s, i))
- || TREE_THIS_VOLATILE (gimple_call_arg (s, i)))
- return true;
-
- return false;
- }
- else if (is_gimple_assign (s))
- {
- /* Skip the first operand, the LHS. */
- for (i = 1; i < gimple_num_ops (s); i++)
- if (TREE_SIDE_EFFECTS (gimple_op (s, i))
- || TREE_THIS_VOLATILE (gimple_op (s, i)))
- {
- gcc_assert (gimple_has_volatile_ops (s));
- return true;
- }
- }
- else if (is_gimple_debug (s))
- return false;
- else
- {
- /* For statements without an LHS, examine all arguments. */
- for (i = 0; i < gimple_num_ops (s); i++)
- if (TREE_SIDE_EFFECTS (gimple_op (s, i))
- || TREE_THIS_VOLATILE (gimple_op (s, i)))
- {
- gcc_assert (gimple_has_volatile_ops (s));
- return true;
- }
- }
-
- return false;
- }
-
/* Helper for gimple_could_trap_p and gimple_assign_rhs_could_trap_p.
Return true if S can trap. When INCLUDE_MEM is true, check whether
the memory operations could trap. When INCLUDE_STORES is true and
--- 2484,2489 ----
Index: gcc/gimple.h
===================================================================
*** gcc/gimple.h (revision 182010)
--- gcc/gimple.h (working copy)
*************** void gimple_cond_get_ops_from_tree (tree
*** 948,954 ****
gimple gimple_build_cond_from_tree (tree, tree, tree);
void gimple_cond_set_condition_from_tree (gimple, tree);
bool gimple_has_side_effects (const_gimple);
- bool gimple_rhs_has_side_effects (const_gimple);
bool gimple_could_trap_p (gimple);
bool gimple_could_trap_p_1 (gimple, bool, bool);
bool gimple_assign_rhs_could_trap_p (gimple);
--- 948,953 ----
Index: gcc/tree-ssa-dom.c
===================================================================
*** gcc/tree-ssa-dom.c (revision 182010)
--- gcc/tree-ssa-dom.c (working copy)
*************** optimize_stmt (basic_block bb, gimple_st
*** 2154,2165 ****
/* Check for redundant computations. Do this optimization only
for assignments that have no volatile ops and conditionals. */
! may_optimize_p = (!gimple_has_volatile_ops (stmt)
! && ((is_gimple_assign (stmt)
! && !gimple_rhs_has_side_effects (stmt))
|| (is_gimple_call (stmt)
! && gimple_call_lhs (stmt) != NULL_TREE
! && !gimple_rhs_has_side_effects (stmt))
|| gimple_code (stmt) == GIMPLE_COND
|| gimple_code (stmt) == GIMPLE_SWITCH));
--- 2154,2163 ----
/* Check for redundant computations. Do this optimization only
for assignments that have no volatile ops and conditionals. */
! may_optimize_p = (!gimple_has_side_effects (stmt)
! && (is_gimple_assign (stmt)
|| (is_gimple_call (stmt)
! && gimple_call_lhs (stmt) != NULL_TREE)
|| gimple_code (stmt) == GIMPLE_COND
|| gimple_code (stmt) == GIMPLE_SWITCH));
