and 0 otherwise. */
static int
-uaddsub_overflow_check_p (gimple *stmt, gimple *use_stmt)
+uaddsub_overflow_check_p (gimple *stmt, gimple *use_stmt, tree maxval)
{
enum tree_code ccode = ERROR_MARK;
tree crhs1 = NULL_TREE, crhs2 = NULL_TREE;
{
case GT_EXPR:
case LE_EXPR:
+ if (maxval)
+ {
+ /* r = a + b; r > maxval or r <= maxval */
+ if (crhs1 == lhs
+ && TREE_CODE (crhs2) == INTEGER_CST
+ && tree_int_cst_equal (crhs2, maxval))
+ return ccode == GT_EXPR ? 1 : -1;
+ break;
+ }
/* r = a - b; r > a or r <= a
r = a + b; a > r or a <= r or b > r or b <= r. */
if ((code == MINUS_EXPR && crhs1 == lhs && crhs2 == rhs1)
break;
case LT_EXPR:
case GE_EXPR:
+ if (maxval)
+ break;
/* r = a - b; a < r or a >= r
r = a + b; r < a or r >= a or r < b or r >= b. */
if ((code == MINUS_EXPR && crhs1 == rhs1 && crhs2 == lhs)
x = REALPART_EXPR <_7>;
_8 = IMAGPART_EXPR <_7>;
if (_8)
- and similarly for addition. */
+ and similarly for addition.
+
+ Also recognize:
+ yc = (type) y;
+ zc = (type) z;
+ x = yc + zc;
+ if (x > max)
+ where y and z have unsigned types with maximum max
+ and there are other uses of x and all of those cast x
+ back to that unsigned type and again replace it with
+ _7 = ADD_OVERFLOW (y, z);
+ _9 = REALPART_EXPR <_7>;
+ _8 = IMAGPART_EXPR <_8>;
+ if (_8)
+ and replace (utype) x with _9. */
static bool
match_uaddsub_overflow (gimple_stmt_iterator *gsi, gimple *stmt,
bool use_seen = false;
bool ovf_use_seen = false;
gimple *use_stmt;
+ gimple *add_stmt = NULL;
+ bool add_first = false;
gcc_checking_assert (code == PLUS_EXPR || code == MINUS_EXPR);
if (!INTEGRAL_TYPE_P (type)
|| !TYPE_UNSIGNED (type)
|| has_zero_uses (lhs)
- || has_single_use (lhs)
- || optab_handler (code == PLUS_EXPR ? uaddv4_optab : usubv4_optab,
- TYPE_MODE (type)) == CODE_FOR_nothing)
+ || (code == MINUS_EXPR
+ && optab_handler (usubv4_optab,
+ TYPE_MODE (type)) == CODE_FOR_nothing))
return false;
FOR_EACH_IMM_USE_FAST (use_p, iter, lhs)
if (is_gimple_debug (use_stmt))
continue;
- if (uaddsub_overflow_check_p (stmt, use_stmt))
+ if (uaddsub_overflow_check_p (stmt, use_stmt, NULL_TREE))
ovf_use_seen = true;
else
use_seen = true;
break;
}
- if (!ovf_use_seen || !use_seen)
- return false;
-
- tree ctype = build_complex_type (type);
tree rhs1 = gimple_assign_rhs1 (stmt);
tree rhs2 = gimple_assign_rhs2 (stmt);
+ tree maxval = NULL_TREE;
+ if (!ovf_use_seen
+ || !use_seen
+ || (code == PLUS_EXPR
+ && optab_handler (uaddv4_optab,
+ TYPE_MODE (type)) == CODE_FOR_nothing))
+ {
+ if (code != PLUS_EXPR)
+ return false;
+ if (TREE_CODE (rhs1) != SSA_NAME
+ || !gimple_assign_cast_p (SSA_NAME_DEF_STMT (rhs1)))
+ return false;
+ rhs1 = gimple_assign_rhs1 (SSA_NAME_DEF_STMT (rhs1));
+ tree type1 = TREE_TYPE (rhs1);
+ if (!INTEGRAL_TYPE_P (type1)
+ || !TYPE_UNSIGNED (type1)
+ || TYPE_PRECISION (type1) >= TYPE_PRECISION (type)
+ || (TYPE_PRECISION (type1)
+ != GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (type1))))
+ return false;
+ if (TREE_CODE (rhs2) == INTEGER_CST)
+ {
+ if (wi::ne_p (wi::rshift (wi::to_wide (rhs2),
+ TYPE_PRECISION (type1),
+ UNSIGNED), 0))
+ return false;
+ rhs2 = fold_convert (type1, rhs2);
+ }
+ else
+ {
+ if (TREE_CODE (rhs2) != SSA_NAME
+ || !gimple_assign_cast_p (SSA_NAME_DEF_STMT (rhs2)))
+ return false;
+ rhs2 = gimple_assign_rhs1 (SSA_NAME_DEF_STMT (rhs2));
+ tree type2 = TREE_TYPE (rhs2);
+ if (!INTEGRAL_TYPE_P (type2)
+ || !TYPE_UNSIGNED (type2)
+ || TYPE_PRECISION (type2) >= TYPE_PRECISION (type)
+ || (TYPE_PRECISION (type2)
+ != GET_MODE_BITSIZE (SCALAR_INT_TYPE_MODE (type2))))
+ return false;
+ }
+ if (TYPE_PRECISION (type1) >= TYPE_PRECISION (TREE_TYPE (rhs2)))
+ type = type1;
+ else
+ type = TREE_TYPE (rhs2);
+
+ if (TREE_CODE (type) != INTEGER_TYPE
+ || optab_handler (uaddv4_optab,
+ TYPE_MODE (type)) == CODE_FOR_nothing)
+ return false;
+
+ maxval = wide_int_to_tree (type, wi::max_value (TYPE_PRECISION (type),
+ UNSIGNED));
+ ovf_use_seen = false;
+ use_seen = false;
+ basic_block use_bb = NULL;
+ FOR_EACH_IMM_USE_FAST (use_p, iter, lhs)
+ {
+ use_stmt = USE_STMT (use_p);
+ if (is_gimple_debug (use_stmt))
+ continue;
+
+ if (uaddsub_overflow_check_p (stmt, use_stmt, maxval))
+ {
+ ovf_use_seen = true;
+ use_bb = gimple_bb (use_stmt);
+ }
+ else
+ {
+ if (!gimple_assign_cast_p (use_stmt)
+ || gimple_assign_rhs_code (use_stmt) == VIEW_CONVERT_EXPR)
+ return false;
+ tree use_lhs = gimple_assign_lhs (use_stmt);
+ if (!INTEGRAL_TYPE_P (TREE_TYPE (use_lhs))
+ || (TYPE_PRECISION (TREE_TYPE (use_lhs))
+ > TYPE_PRECISION (type)))
+ return false;
+ use_seen = true;
+ }
+ }
+ if (!ovf_use_seen)
+ return false;
+ if (!useless_type_conversion_p (type, TREE_TYPE (rhs1)))
+ {
+ if (!use_seen)
+ return false;
+ tree new_rhs1 = make_ssa_name (type);
+ gimple *g = gimple_build_assign (new_rhs1, NOP_EXPR, rhs1);
+ gsi_insert_before (gsi, g, GSI_SAME_STMT);
+ rhs1 = new_rhs1;
+ }
+ else if (!useless_type_conversion_p (type, TREE_TYPE (rhs2)))
+ {
+ if (!use_seen)
+ return false;
+ tree new_rhs2 = make_ssa_name (type);
+ gimple *g = gimple_build_assign (new_rhs2, NOP_EXPR, rhs2);
+ gsi_insert_before (gsi, g, GSI_SAME_STMT);
+ rhs2 = new_rhs2;
+ }
+ else if (!use_seen)
+ {
+ /* If there are no uses of the wider addition, check if
+ forwprop has not created a narrower addition.
+ Require it to be in the same bb as the overflow check. */
+ FOR_EACH_IMM_USE_FAST (use_p, iter, rhs1)
+ {
+ use_stmt = USE_STMT (use_p);
+ if (is_gimple_debug (use_stmt))
+ continue;
+
+ if (use_stmt == stmt)
+ continue;
+
+ if (!is_gimple_assign (use_stmt)
+ || gimple_bb (use_stmt) != use_bb
+ || gimple_assign_rhs_code (use_stmt) != PLUS_EXPR)
+ continue;
+
+ if (gimple_assign_rhs1 (use_stmt) == rhs1)
+ {
+ if (!operand_equal_p (gimple_assign_rhs2 (use_stmt),
+ rhs2, 0))
+ continue;
+ }
+ else if (gimple_assign_rhs2 (use_stmt) == rhs1)
+ {
+ if (gimple_assign_rhs1 (use_stmt) != rhs2)
+ continue;
+ }
+ else
+ continue;
+
+ add_stmt = use_stmt;
+ break;
+ }
+ if (add_stmt == NULL)
+ return false;
+
+ /* If stmt and add_stmt are in the same bb, we need to find out
+ which one is earlier. If they are in different bbs, we've
+ checked add_stmt is in the same bb as one of the uses of the
+ stmt lhs, so stmt needs to dominate add_stmt too. */
+ if (gimple_bb (stmt) == gimple_bb (add_stmt))
+ {
+ gimple_stmt_iterator gsif = *gsi;
+ gimple_stmt_iterator gsib = *gsi;
+ int i;
+ /* Search both forward and backward from stmt and have a small
+ upper bound. */
+ for (i = 0; i < 128; i++)
+ {
+ if (!gsi_end_p (gsib))
+ {
+ gsi_prev_nondebug (&gsib);
+ if (gsi_stmt (gsib) == add_stmt)
+ {
+ add_first = true;
+ break;
+ }
+ }
+ else if (gsi_end_p (gsif))
+ break;
+ if (!gsi_end_p (gsif))
+ {
+ gsi_next_nondebug (&gsif);
+ if (gsi_stmt (gsif) == add_stmt)
+ break;
+ }
+ }
+ if (i == 128)
+ return false;
+ if (add_first)
+ *gsi = gsi_for_stmt (add_stmt);
+ }
+ }
+ }
+
+ tree ctype = build_complex_type (type);
gcall *g = gimple_build_call_internal (code == PLUS_EXPR
? IFN_ADD_OVERFLOW : IFN_SUB_OVERFLOW,
2, rhs1, rhs2);
tree ctmp = make_ssa_name (ctype);
gimple_call_set_lhs (g, ctmp);
gsi_insert_before (gsi, g, GSI_SAME_STMT);
- gassign *g2 = gimple_build_assign (lhs, REALPART_EXPR,
+ tree new_lhs = maxval ? make_ssa_name (type) : lhs;
+ gassign *g2 = gimple_build_assign (new_lhs, REALPART_EXPR,
build1 (REALPART_EXPR, type, ctmp));
- gsi_replace (gsi, g2, true);
+ if (maxval)
+ {
+ gsi_insert_before (gsi, g2, GSI_SAME_STMT);
+ if (add_first)
+ *gsi = gsi_for_stmt (stmt);
+ }
+ else
+ gsi_replace (gsi, g2, true);
tree ovf = make_ssa_name (type);
g2 = gimple_build_assign (ovf, IMAGPART_EXPR,
build1 (IMAGPART_EXPR, type, ctmp));
if (is_gimple_debug (use_stmt))
continue;
- int ovf_use = uaddsub_overflow_check_p (stmt, use_stmt);
+ int ovf_use = uaddsub_overflow_check_p (stmt, use_stmt, maxval);
if (ovf_use == 0)
- continue;
+ {
+ if (maxval)
+ {
+ tree use_lhs = gimple_assign_lhs (use_stmt);
+ gimple_assign_set_rhs1 (use_stmt, new_lhs);
+ if (useless_type_conversion_p (TREE_TYPE (use_lhs),
+ TREE_TYPE (new_lhs)))
+ gimple_assign_set_rhs_code (use_stmt, SSA_NAME);
+ update_stmt (use_stmt);
+ }
+ continue;
+ }
if (gimple_code (use_stmt) == GIMPLE_COND)
{
gcond *cond_stmt = as_a <gcond *> (use_stmt);
}
update_stmt (use_stmt);
}
+ if (maxval)
+ {
+ gimple_stmt_iterator gsi2 = gsi_for_stmt (stmt);
+ gsi_remove (&gsi2, true);
+ if (add_stmt)
+ {
+ gimple *g = gimple_build_assign (gimple_assign_lhs (add_stmt),
+ new_lhs);
+ gsi2 = gsi_for_stmt (add_stmt);
+ gsi_replace (&gsi2, g, true);
+ }
+ }
return true;
}
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