This fixes PR50082 by completely defering to fold what kind of
overflow warning to emit from tree-ssa-forwprop.c. It also moves
overflow handling to the single place that decides whether and
what we optimize.
Bootstrapped and tested on x86_64-unknown-linux-gnu.
Ian, does this look ok?
Thanks,
Richard.
2011-08-16 Richard GUenther <rguent...@suse.de>
PR tree-optimization/50082
* tree-ssa-forwprop.c (combine_cond_expr_cond): Handle overflow
warnings here, instead of ...
(ssa_forward_propagate_and_combine): ... here.
(forward_propagate_into_comparison_1): Adjust.
(forward_propagate_into_comparison): Likewise.
(forward_propagate_into_gimple_cond): Likewise.
(forward_propagate_into_cond): Likewise.
Index: gcc/tree-ssa-forwprop.c
===================================================================
*** gcc/tree-ssa-forwprop.c (revision 177781)
--- gcc/tree-ssa-forwprop.c (working copy)
*************** rhs_to_tree (tree type, gimple stmt)
*** 369,384 ****
considered simplified. */
static tree
! combine_cond_expr_cond (location_t loc, enum tree_code code, tree type,
tree op0, tree op1, bool invariant_only)
{
tree t;
gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison);
! t = fold_binary_loc (loc, code, type, op0, op1);
if (!t)
! return NULL_TREE;
/* Require that we got a boolean type out if we put one in. */
gcc_assert (TREE_CODE (TREE_TYPE (t)) == TREE_CODE (type));
--- 369,388 ----
considered simplified. */
static tree
! combine_cond_expr_cond (gimple stmt, enum tree_code code, tree type,
tree op0, tree op1, bool invariant_only)
{
tree t;
gcc_assert (TREE_CODE_CLASS (code) == tcc_comparison);
! fold_defer_overflow_warnings ();
! t = fold_binary_loc (gimple_location (stmt), code, type, op0, op1);
if (!t)
! {
! fold_undefer_overflow_warnings (false, NULL, 0);
! return NULL_TREE;
! }
/* Require that we got a boolean type out if we put one in. */
gcc_assert (TREE_CODE (TREE_TYPE (t)) == TREE_CODE (type));
*************** combine_cond_expr_cond (location_t loc,
*** 388,394 ****
/* Bail out if we required an invariant but didn't get one. */
if (!t || (invariant_only && !is_gimple_min_invariant (t)))
! return NULL_TREE;
return t;
}
--- 392,403 ----
/* Bail out if we required an invariant but didn't get one. */
if (!t || (invariant_only && !is_gimple_min_invariant (t)))
! {
! fold_undefer_overflow_warnings (false, NULL, 0);
! return NULL_TREE;
! }
!
! fold_undefer_overflow_warnings (!gimple_no_warning_p (stmt), stmt, 0);
return t;
}
*************** combine_cond_expr_cond (location_t loc,
*** 398,404 ****
were no simplifying combines. */
static tree
! forward_propagate_into_comparison_1 (location_t loc,
enum tree_code code, tree type,
tree op0, tree op1)
{
--- 407,413 ----
were no simplifying combines. */
static tree
! forward_propagate_into_comparison_1 (gimple stmt,
enum tree_code code, tree type,
tree op0, tree op1)
{
*************** forward_propagate_into_comparison_1 (loc
*** 414,420 ****
if (def_stmt && can_propagate_from (def_stmt))
{
rhs0 = rhs_to_tree (TREE_TYPE (op1), def_stmt);
! tmp = combine_cond_expr_cond (loc, code, type,
rhs0, op1, !single_use0_p);
if (tmp)
return tmp;
--- 423,429 ----
if (def_stmt && can_propagate_from (def_stmt))
{
rhs0 = rhs_to_tree (TREE_TYPE (op1), def_stmt);
! tmp = combine_cond_expr_cond (stmt, code, type,
rhs0, op1, !single_use0_p);
if (tmp)
return tmp;
*************** forward_propagate_into_comparison_1 (loc
*** 428,434 ****
if (def_stmt && can_propagate_from (def_stmt))
{
rhs1 = rhs_to_tree (TREE_TYPE (op0), def_stmt);
! tmp = combine_cond_expr_cond (loc, code, type,
op0, rhs1, !single_use1_p);
if (tmp)
return tmp;
--- 437,443 ----
if (def_stmt && can_propagate_from (def_stmt))
{
rhs1 = rhs_to_tree (TREE_TYPE (op0), def_stmt);
! tmp = combine_cond_expr_cond (stmt, code, type,
op0, rhs1, !single_use1_p);
if (tmp)
return tmp;
*************** forward_propagate_into_comparison_1 (loc
*** 438,444 ****
/* If that wasn't successful either, try both operands. */
if (rhs0 != NULL_TREE
&& rhs1 != NULL_TREE)
! tmp = combine_cond_expr_cond (loc, code, type,
rhs0, rhs1,
!(single_use0_p && single_use1_p));
--- 447,453 ----
/* If that wasn't successful either, try both operands. */
if (rhs0 != NULL_TREE
&& rhs1 != NULL_TREE)
! tmp = combine_cond_expr_cond (stmt, code, type,
rhs0, rhs1,
!(single_use0_p && single_use1_p));
*************** forward_propagate_into_comparison (gimpl
*** 460,466 ****
tree rhs2 = gimple_assign_rhs2 (stmt);
/* Combine the comparison with defining statements. */
! tmp = forward_propagate_into_comparison_1 (gimple_location (stmt),
gimple_assign_rhs_code (stmt),
TREE_TYPE
(gimple_assign_lhs (stmt)),
--- 469,475 ----
tree rhs2 = gimple_assign_rhs2 (stmt);
/* Combine the comparison with defining statements. */
! tmp = forward_propagate_into_comparison_1 (stmt,
gimple_assign_rhs_code (stmt),
TREE_TYPE
(gimple_assign_lhs (stmt)),
*************** forward_propagate_into_comparison (gimpl
*** 491,497 ****
static int
forward_propagate_into_gimple_cond (gimple stmt)
{
- location_t loc = gimple_location (stmt);
tree tmp;
enum tree_code code = gimple_cond_code (stmt);
bool cfg_changed = false;
--- 500,505 ----
*************** forward_propagate_into_gimple_cond (gimp
*** 502,508 ****
if (TREE_CODE_CLASS (gimple_cond_code (stmt)) != tcc_comparison)
return 0;
! tmp = forward_propagate_into_comparison_1 (loc, code,
boolean_type_node,
rhs1, rhs2);
if (tmp)
--- 510,516 ----
if (TREE_CODE_CLASS (gimple_cond_code (stmt)) != tcc_comparison)
return 0;
! tmp = forward_propagate_into_comparison_1 (stmt, code,
boolean_type_node,
rhs1, rhs2);
if (tmp)
*************** static int
*** 541,553 ****
forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
{
gimple stmt = gsi_stmt (*gsi_p);
- location_t loc = gimple_location (stmt);
tree tmp = NULL_TREE;
tree cond = gimple_assign_rhs1 (stmt);
/* We can do tree combining on SSA_NAME and comparison expressions. */
if (COMPARISON_CLASS_P (cond))
! tmp = forward_propagate_into_comparison_1 (loc, TREE_CODE (cond),
boolean_type_node,
TREE_OPERAND (cond, 0),
TREE_OPERAND (cond, 1));
--- 549,560 ----
forward_propagate_into_cond (gimple_stmt_iterator *gsi_p)
{
gimple stmt = gsi_stmt (*gsi_p);
tree tmp = NULL_TREE;
tree cond = gimple_assign_rhs1 (stmt);
/* We can do tree combining on SSA_NAME and comparison expressions. */
if (COMPARISON_CLASS_P (cond))
! tmp = forward_propagate_into_comparison_1 (stmt, TREE_CODE (cond),
boolean_type_node,
TREE_OPERAND (cond, 0),
TREE_OPERAND (cond, 1));
*************** forward_propagate_into_cond (gimple_stmt
*** 559,565 ****
return 0;
rhs0 = gimple_assign_rhs1 (def_stmt);
! tmp = combine_cond_expr_cond (loc, NE_EXPR, boolean_type_node, rhs0,
build_int_cst (TREE_TYPE (rhs0), 0),
false);
}
--- 566,572 ----
return 0;
rhs0 = gimple_assign_rhs1 (def_stmt);
! tmp = combine_cond_expr_cond (stmt, NE_EXPR, boolean_type_node, rhs0,
build_int_cst (TREE_TYPE (rhs0), 0),
false);
}
*************** ssa_forward_propagate_and_combine (void)
*** 2440,2466 ****
{
/* In this case the entire COND_EXPR is in rhs1. */
int did_something;
- fold_defer_overflow_warnings ();
did_something = forward_propagate_into_cond (&gsi);
stmt = gsi_stmt (gsi);
if (did_something == 2)
cfg_changed = true;
- fold_undefer_overflow_warnings
- (!TREE_NO_WARNING (rhs1) && did_something, stmt,
- WARN_STRICT_OVERFLOW_CONDITIONAL);
changed = did_something != 0;
}
else if (TREE_CODE_CLASS (code) == tcc_comparison)
{
- bool no_warning = gimple_no_warning_p (stmt);
int did_something;
- fold_defer_overflow_warnings ();
did_something = forward_propagate_into_comparison (&gsi);
if (did_something == 2)
cfg_changed = true;
- fold_undefer_overflow_warnings
- (!no_warning && changed,
- stmt, WARN_STRICT_OVERFLOW_CONDITIONAL);
changed = did_something != 0;
}
else if (code == BIT_AND_EXPR
--- 2447,2464 ----
*************** ssa_forward_propagate_and_combine (void)
*** 2489,2500 ****
case GIMPLE_COND:
{
int did_something;
- fold_defer_overflow_warnings ();
did_something = forward_propagate_into_gimple_cond (stmt);
if (did_something == 2)
cfg_changed = true;
- fold_undefer_overflow_warnings
- (did_something, stmt, WARN_STRICT_OVERFLOW_CONDITIONAL);
changed = did_something != 0;
break;
}
--- 2487,2495 ----
