static tree fold_negate_const (tree, tree);
static tree fold_not_const (tree, tree);
static tree fold_relational_const (enum tree_code, tree, tree, tree);
-static bool tree_expr_nonzero_p (tree);
/* We know that A1 + B1 = SUM1, using 2's complement arithmetic and ignoring
overflow. Suppose A, B and SUM have the same respective signs as A1, B1,
}
}
\f
-/* Return false if expr can be assumed not to be an value, true
+/* Return false if expr can be assumed not to be an lvalue, true
otherwise. */
static bool
arg0 = op0;
if (arg0)
{
- if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
+ if (code == NOP_EXPR || code == CONVERT_EXPR
+ || code == FLOAT_EXPR || code == ABS_EXPR)
{
- /* Don't use STRIP_NOPS, because signedness of argument type matters. */
+ /* Don't use STRIP_NOPS, because signedness of argument type
+ matters. */
STRIP_SIGN_NOPS (arg0);
}
else
return fold_build1 (code, type, TREE_OPERAND (op0, 0));
}
+ /* Handle (T *)&A.B.C for A being of type T and B and C
+ living at offset zero. This occurs frequently in
+ C++ upcasting and then accessing the base. */
+ if (TREE_CODE (op0) == ADDR_EXPR
+ && POINTER_TYPE_P (type)
+ && handled_component_p (TREE_OPERAND (op0, 0)))
+ {
+ HOST_WIDE_INT bitsize, bitpos;
+ tree offset;
+ enum machine_mode mode;
+ int unsignedp, volatilep;
+ tree base = TREE_OPERAND (op0, 0);
+ base = get_inner_reference (base, &bitsize, &bitpos, &offset,
+ &mode, &unsignedp, &volatilep, false);
+ /* If the reference was to a (constant) zero offset, we can use
+ the address of the base if it has the same base type
+ as the result type. */
+ if (! offset && bitpos == 0
+ && TYPE_MAIN_VARIANT (TREE_TYPE (type))
+ == TYPE_MAIN_VARIANT (TREE_TYPE (base)))
+ return fold_convert (type, build_fold_addr_expr (base));
+ }
+
if (TREE_CODE (op0) == MODIFY_EXPR
&& TREE_CONSTANT (TREE_OPERAND (op0, 1))
/* Detect assigning a bitfield. */
goto bit_ior;
}
+ /* (X | Y) ^ X -> Y & ~ X*/
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 0), arg1, 0))
+ {
+ tree t2 = TREE_OPERAND (arg0, 1);
+ t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
+ arg1);
+ t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
+ fold_convert (type, t1));
+ return t1;
+ }
+
+ /* (Y | X) ^ X -> Y & ~ X*/
+ if (TREE_CODE (arg0) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg0, 1), arg1, 0))
+ {
+ tree t2 = TREE_OPERAND (arg0, 0);
+ t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg1),
+ arg1);
+ t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
+ fold_convert (type, t1));
+ return t1;
+ }
+
+ /* X ^ (X | Y) -> Y & ~ X*/
+ if (TREE_CODE (arg1) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg1, 0), arg0, 0))
+ {
+ tree t2 = TREE_OPERAND (arg1, 1);
+ t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
+ arg0);
+ t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
+ fold_convert (type, t1));
+ return t1;
+ }
+
+ /* X ^ (Y | X) -> Y & ~ X*/
+ if (TREE_CODE (arg1) == BIT_IOR_EXPR
+ && operand_equal_p (TREE_OPERAND (arg1, 1), arg0, 0))
+ {
+ tree t2 = TREE_OPERAND (arg1, 0);
+ t1 = fold_build1 (BIT_NOT_EXPR, TREE_TYPE (arg0),
+ arg0);
+ t1 = fold_build2 (BIT_AND_EXPR, type, fold_convert (type, t2),
+ fold_convert (type, t1));
+ return t1;
+ }
+
/* Convert ~X ^ ~Y to X ^ Y. */
if (TREE_CODE (arg0) == BIT_NOT_EXPR
&& TREE_CODE (arg1) == BIT_NOT_EXPR)
}
if ((code == EQ_EXPR || code == NE_EXPR)
- && !TREE_SIDE_EFFECTS (arg0)
&& integer_zerop (arg1)
&& tree_expr_nonzero_p (arg0))
- return constant_boolean_node (code==NE_EXPR, type);
+ {
+ tree res = constant_boolean_node (code==NE_EXPR, type);
+ return omit_one_operand (type, res, arg0);
+ }
t1 = fold_relational_const (code, type, arg0, arg1);
return t1 == NULL_TREE ? NULL_TREE : t1;
tree
fold_build1 (enum tree_code code, tree type, tree op0)
{
- tree tem = fold_unary (code, type, op0);
- if (tem)
- return tem;
+ tree tem;
+#ifdef ENABLE_FOLD_CHECKING
+ unsigned char checksum_before[16], checksum_after[16];
+ struct md5_ctx ctx;
+ htab_t ht;
- return build1 (code, type, op0);
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before);
+ htab_empty (ht);
+#endif
+
+ tem = fold_unary (code, type, op0);
+ if (!tem)
+ tem = build1 (code, type, op0);
+
+#ifdef ENABLE_FOLD_CHECKING
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after);
+ htab_delete (ht);
+
+ if (memcmp (checksum_before, checksum_after, 16))
+ fold_check_failed (op0, tem);
+#endif
+ return tem;
}
/* Fold a binary tree expression with code CODE of type TYPE with
tree
fold_build2 (enum tree_code code, tree type, tree op0, tree op1)
{
- tree tem = fold_binary (code, type, op0, op1);
- if (tem)
- return tem;
+ tree tem;
+#ifdef ENABLE_FOLD_CHECKING
+ unsigned char checksum_before_op0[16],
+ checksum_before_op1[16],
+ checksum_after_op0[16],
+ checksum_after_op1[16];
+ struct md5_ctx ctx;
+ htab_t ht;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op0);
+ htab_empty (ht);
- return build2 (code, type, op0, op1);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op1, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op1);
+ htab_empty (ht);
+#endif
+
+ tem = fold_binary (code, type, op0, op1);
+ if (!tem)
+ tem = build2 (code, type, op0, op1);
+
+#ifdef ENABLE_FOLD_CHECKING
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op0);
+ htab_empty (ht);
+
+ if (memcmp (checksum_before_op0, checksum_after_op0, 16))
+ fold_check_failed (op0, tem);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op1, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op1);
+ htab_delete (ht);
+
+ if (memcmp (checksum_before_op1, checksum_after_op1, 16))
+ fold_check_failed (op1, tem);
+#endif
+ return tem;
}
/* Fold a ternary tree expression with code CODE of type TYPE with
tree
fold_build3 (enum tree_code code, tree type, tree op0, tree op1, tree op2)
-{
- tree tem = fold_ternary (code, type, op0, op1, op2);
- if (tem)
- return tem;
+{ tree tem;
+#ifdef ENABLE_FOLD_CHECKING
+ unsigned char checksum_before_op0[16],
+ checksum_before_op1[16],
+ checksum_before_op2[16],
+ checksum_after_op0[16],
+ checksum_after_op1[16],
+ checksum_after_op2[16];
+ struct md5_ctx ctx;
+ htab_t ht;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op0);
+ htab_empty (ht);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op1, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op1);
+ htab_empty (ht);
- return build3 (code, type, op0, op1, op2);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op2, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before_op2);
+ htab_empty (ht);
+#endif
+
+ tem = fold_ternary (code, type, op0, op1, op2);
+ if (!tem)
+ tem = build3 (code, type, op0, op1, op2);
+
+#ifdef ENABLE_FOLD_CHECKING
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op0, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op0);
+ htab_empty (ht);
+
+ if (memcmp (checksum_before_op0, checksum_after_op0, 16))
+ fold_check_failed (op0, tem);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op1, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op1);
+ htab_empty (ht);
+
+ if (memcmp (checksum_before_op1, checksum_after_op1, 16))
+ fold_check_failed (op1, tem);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (op2, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after_op2);
+ htab_delete (ht);
+
+ if (memcmp (checksum_before_op2, checksum_after_op2, 16))
+ fold_check_failed (op2, tem);
+#endif
+ return tem;
}
/* Perform constant folding and related simplification of initializer
int
tree_expr_nonnegative_p (tree t)
{
+ if (TYPE_UNSIGNED (TREE_TYPE (t)))
+ return 1;
+
switch (TREE_CODE (t))
{
case ABS_EXPR:
/* We can't return 1 if flag_wrapv is set because
ABS_EXPR<INT_MIN> = INT_MIN. */
- if (!flag_wrapv)
+ if (!(flag_wrapv && INTEGRAL_TYPE_P (TREE_TYPE (t))))
return 1;
break;
For floating point we further ensure that T is not denormal.
Similar logic is present in nonzero_address in rtlanal.h. */
-static bool
+bool
tree_expr_nonzero_p (tree t)
{
tree type = TREE_TYPE (t);
return tree_expr_nonzero_p (TREE_OPERAND (t, 1))
|| tree_expr_nonzero_p (TREE_OPERAND (t, 0));
+ case CALL_EXPR:
+ return alloca_call_p (t);
+
default:
break;
}
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