#include "ggc.h"
#include "hashtab.h"
#include "langhooks.h"
+#include "md5.h"
static void encode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT, HOST_WIDE_INT);
static void decode (HOST_WIDE_INT *, unsigned HOST_WIDE_INT *, HOST_WIDE_INT *);
}
return NULL_TREE;
}
-
+
/* Perform constant folding and related simplification of EXPR.
The related simplifications include x*1 => x, x*0 => 0, etc.,
and application of the associative law.
We cannot simplify through a CONVERT_EXPR, FIX_EXPR or FLOAT_EXPR,
but we can constant-fold them if they have constant operands. */
+#ifdef ENABLE_FOLD_CHECKING
+# define fold(x) fold_1 (x)
+static tree fold_1 (tree);
+static
+#endif
tree
fold (tree expr)
{
- tree t = expr;
+ tree t = expr, orig_t;
tree t1 = NULL_TREE;
tree tem;
tree type = TREE_TYPE (expr);
#ifdef MAX_INTEGER_COMPUTATION_MODE
check_max_integer_computation_mode (expr);
#endif
+ orig_t = t;
if (code == NOP_EXPR || code == FLOAT_EXPR || code == CONVERT_EXPR)
{
if ((code == PLUS_EXPR || code == MULT_EXPR || code == MIN_EXPR
|| code == MAX_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR
|| code == BIT_AND_EXPR)
- && (TREE_CODE (arg0) == INTEGER_CST || TREE_CODE (arg0) == REAL_CST))
+ && ((TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) != INTEGER_CST)
+ || (TREE_CODE (arg0) == REAL_CST && TREE_CODE (arg1) != REAL_CST)))
{
tem = arg0; arg0 = arg1; arg1 = tem;
- tem = TREE_OPERAND (t, 0); TREE_OPERAND (t, 0) = TREE_OPERAND (t, 1);
- TREE_OPERAND (t, 1) = tem;
+ if (t == orig_t)
+ t = copy_node (t);
+ TREE_OPERAND (t, 0) = arg0;
+ TREE_OPERAND (t, 1) = arg1;
}
/* Now WINS is set as described above,
/* Don't leave an assignment inside a conversion
unless assigning a bitfield. */
tree prev = TREE_OPERAND (t, 0);
+ if (t == orig_t)
+ t = copy_node (t);
TREE_OPERAND (t, 0) = TREE_OPERAND (prev, 1);
/* First do the assignment, then return converted constant. */
t = build (COMPOUND_EXPR, TREE_TYPE (t), prev, fold (t));
if (!wins)
{
- TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
+ if (TREE_CONSTANT (t) != TREE_CONSTANT (arg0))
+ {
+ if (t == orig_t)
+ t = copy_node (t);
+ TREE_CONSTANT (t) = TREE_CONSTANT (arg0);
+ }
return t;
}
return fold_convert (t, arg0);
return t;
case RANGE_EXPR:
- TREE_CONSTANT (t) = wins;
+ if (TREE_CONSTANT (t) != wins)
+ {
+ if (t == orig_t)
+ t = copy_node (t);
+ TREE_CONSTANT (t) = wins;
+ }
return t;
case NEGATE_EXPR:
RROTATE_EXPR by a new constant. */
if (code == LROTATE_EXPR && TREE_CODE (arg1) == INTEGER_CST)
{
+ if (t == orig_t)
+ t = copy_node (t);
TREE_SET_CODE (t, RROTATE_EXPR);
code = RROTATE_EXPR;
TREE_OPERAND (t, 1) = arg1
|| (TREE_CODE (arg0) == REAL_CST
&& TREE_CODE (arg0) != REAL_CST))
{
+ if (t == orig_t)
+ t = copy_node (t);
TREE_OPERAND (t, 0) = arg1;
TREE_OPERAND (t, 1) = arg0;
arg0 = TREE_OPERAND (t, 0);
arg0);
case GE_EXPR:
code = EQ_EXPR;
+ if (t == orig_t)
+ t = copy_node (t);
TREE_SET_CODE (t, EQ_EXPR);
break;
case LE_EXPR:
arg0);
case LT_EXPR:
code = NE_EXPR;
+ if (t == orig_t)
+ t = copy_node (t);
TREE_SET_CODE (t, NE_EXPR);
break;
arg0);
case LE_EXPR:
code = EQ_EXPR;
+ if (t == orig_t)
+ t = copy_node (t);
TREE_SET_CODE (t, EQ_EXPR);
break;
arg0);
case GT_EXPR:
code = NE_EXPR;
+ if (t == orig_t)
+ t = copy_node (t);
TREE_SET_CODE (t, NE_EXPR);
break;
|| ! HONOR_NANS (TYPE_MODE (TREE_TYPE (arg0))))
return constant_boolean_node (1, type);
code = EQ_EXPR;
+ if (t == orig_t)
+ t = copy_node (t);
TREE_SET_CODE (t, code);
break;
} /* switch (code) */
}
+#ifdef ENABLE_FOLD_CHECKING
+#undef fold
+
+static void fold_checksum_tree (tree, struct md5_ctx *, htab_t);
+static void fold_check_failed (tree, tree);
+void print_fold_checksum (tree);
+
+/* When --enable-checking=fold, compute a digest of expr before
+ and after actual fold call to see if fold did not accidentally
+ change original expr. */
+
+tree
+fold (tree expr)
+{
+ tree ret;
+ struct md5_ctx ctx;
+ unsigned char checksum_before[16], checksum_after[16];
+ htab_t ht;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (expr, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_before);
+ htab_empty (ht);
+
+ ret = fold_1 (expr);
+
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (expr, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum_after);
+ htab_delete (ht);
+
+ if (memcmp (checksum_before, checksum_after, 16))
+ fold_check_failed (expr, ret);
+
+ return ret;
+}
+
+void
+print_fold_checksum (tree expr)
+{
+ struct md5_ctx ctx;
+ unsigned char checksum[16], cnt;
+ htab_t ht;
+
+ ht = htab_create (32, htab_hash_pointer, htab_eq_pointer, NULL);
+ md5_init_ctx (&ctx);
+ fold_checksum_tree (expr, &ctx, ht);
+ md5_finish_ctx (&ctx, checksum);
+ htab_delete (ht);
+ for (cnt = 0; cnt < 16; ++cnt)
+ fprintf (stderr, "%02x", checksum[cnt]);
+ putc ('\n', stderr);
+}
+
+static void
+fold_check_failed (tree expr ATTRIBUTE_UNUSED, tree ret ATTRIBUTE_UNUSED)
+{
+ internal_error ("fold check: original tree changed by fold");
+}
+
+static void
+fold_checksum_tree (tree expr, struct md5_ctx *ctx, htab_t ht)
+{
+ void **slot;
+ enum tree_code code;
+ char buf[sizeof (struct tree_decl)];
+ int i, len;
+
+ if (sizeof (struct tree_exp) + 5 * sizeof (tree)
+ > sizeof (struct tree_decl)
+ || sizeof (struct tree_type) > sizeof (struct tree_decl))
+ abort ();
+ if (expr == NULL)
+ return;
+ slot = htab_find_slot (ht, expr, INSERT);
+ if (*slot != NULL)
+ return;
+ *slot = expr;
+ code = TREE_CODE (expr);
+ if (code == SAVE_EXPR && SAVE_EXPR_NOPLACEHOLDER (expr))
+ {
+ /* Allow SAVE_EXPR_NOPLACEHOLDER flag to be modified. */
+ memcpy (buf, expr, tree_size (expr));
+ expr = (tree) buf;
+ SAVE_EXPR_NOPLACEHOLDER (expr) = 0;
+ }
+ else if (TREE_CODE_CLASS (code) == 'd' && DECL_ASSEMBLER_NAME_SET_P (expr))
+ {
+ /* Allow DECL_ASSEMBLER_NAME to be modified. */
+ memcpy (buf, expr, tree_size (expr));
+ expr = (tree) buf;
+ SET_DECL_ASSEMBLER_NAME (expr, NULL);
+ }
+ else if (TREE_CODE_CLASS (code) == 't'
+ && (TYPE_POINTER_TO (expr) || TYPE_REFERENCE_TO (expr)))
+ {
+ /* Allow TYPE_POINTER_TO and TYPE_REFERENCE_TO to be modified. */
+ memcpy (buf, expr, tree_size (expr));
+ expr = (tree) buf;
+ TYPE_POINTER_TO (expr) = NULL;
+ TYPE_REFERENCE_TO (expr) = NULL;
+ }
+ md5_process_bytes (expr, tree_size (expr), ctx);
+ fold_checksum_tree (TREE_TYPE (expr), ctx, ht);
+ if (TREE_CODE_CLASS (code) != 't' && TREE_CODE_CLASS (code) != 'd')
+ fold_checksum_tree (TREE_CHAIN (expr), ctx, ht);
+ len = TREE_CODE_LENGTH (code);
+ switch (TREE_CODE_CLASS (code))
+ {
+ case 'c':
+ switch (code)
+ {
+ case STRING_CST:
+ md5_process_bytes (TREE_STRING_POINTER (expr),
+ TREE_STRING_LENGTH (expr), ctx);
+ break;
+ case COMPLEX_CST:
+ fold_checksum_tree (TREE_REALPART (expr), ctx, ht);
+ fold_checksum_tree (TREE_IMAGPART (expr), ctx, ht);
+ break;
+ case VECTOR_CST:
+ fold_checksum_tree (TREE_VECTOR_CST_ELTS (expr), ctx, ht);
+ break;
+ default:
+ break;
+ }
+ break;
+ case 'x':
+ switch (code)
+ {
+ case TREE_LIST:
+ fold_checksum_tree (TREE_PURPOSE (expr), ctx, ht);
+ fold_checksum_tree (TREE_VALUE (expr), ctx, ht);
+ break;
+ case TREE_VEC:
+ for (i = 0; i < TREE_VEC_LENGTH (expr); ++i)
+ fold_checksum_tree (TREE_VEC_ELT (expr, i), ctx, ht);
+ break;
+ default:
+ break;
+ }
+ break;
+ case 'e':
+ switch (code)
+ {
+ case SAVE_EXPR: len = 2; break;
+ case GOTO_SUBROUTINE_EXPR: len = 0; break;
+ case RTL_EXPR: len = 0; break;
+ case WITH_CLEANUP_EXPR: len = 2; break;
+ default: break;
+ }
+ /* FALLTHROUGH */
+ case 'r':
+ case '<':
+ case '1':
+ case '2':
+ case 's':
+ for (i = 0; i < len; ++i)
+ fold_checksum_tree (TREE_OPERAND (expr, i), ctx, ht);
+ break;
+ case 'd':
+ fold_checksum_tree (DECL_SIZE (expr), ctx, ht);
+ fold_checksum_tree (DECL_SIZE_UNIT (expr), ctx, ht);
+ fold_checksum_tree (DECL_NAME (expr), ctx, ht);
+ fold_checksum_tree (DECL_CONTEXT (expr), ctx, ht);
+ fold_checksum_tree (DECL_ARGUMENTS (expr), ctx, ht);
+ fold_checksum_tree (DECL_RESULT_FLD (expr), ctx, ht);
+ fold_checksum_tree (DECL_INITIAL (expr), ctx, ht);
+ fold_checksum_tree (DECL_ABSTRACT_ORIGIN (expr), ctx, ht);
+ fold_checksum_tree (DECL_SECTION_NAME (expr), ctx, ht);
+ fold_checksum_tree (DECL_ATTRIBUTES (expr), ctx, ht);
+ fold_checksum_tree (DECL_VINDEX (expr), ctx, ht);
+ break;
+ case 't':
+ fold_checksum_tree (TYPE_VALUES (expr), ctx, ht);
+ fold_checksum_tree (TYPE_SIZE (expr), ctx, ht);
+ fold_checksum_tree (TYPE_SIZE_UNIT (expr), ctx, ht);
+ fold_checksum_tree (TYPE_ATTRIBUTES (expr), ctx, ht);
+ fold_checksum_tree (TYPE_NAME (expr), ctx, ht);
+ fold_checksum_tree (TYPE_MIN_VALUE (expr), ctx, ht);
+ fold_checksum_tree (TYPE_MAX_VALUE (expr), ctx, ht);
+ fold_checksum_tree (TYPE_MAIN_VARIANT (expr), ctx, ht);
+ fold_checksum_tree (TYPE_BINFO (expr), ctx, ht);
+ fold_checksum_tree (TYPE_CONTEXT (expr), ctx, ht);
+ break;
+ default:
+ break;
+ }
+}
+
+#endif
+
/* Perform constant folding and related simplification of intializer
expression EXPR. This behaves identically to "fold" but ignores
potential run-time traps and exceptions that fold must preserve. */
projects / thirdparty / gcc.git / commitdiff
