tree.def

gcc库的原代码,对编程有很大帮助.

   to the values in the template.

   These "self-references" are doing using a PLACEHOLDER_EXPR.  This is a
   node that will later be replaced with the object being referenced.  Its type
   is that of the object and selects which object to use from a chain of
   references (see below).

   When we wish to evaluate a size or offset, we check it is contains a
   placeholder.  If it does, we construct a WITH_RECORD_EXPR that contains
   both the expression we wish to evaluate and an expression within which the
   object may be found.  The latter expression is the object itself in
   the simple case of an Ada record with discriminant, but it can be the
   array in the case of an unconstrained array.

   In the latter case, we need the fat pointer, because the bounds of the
   array can only be accessed from it.  However, we rely here on the fact that
   the expression for the array contains the dereference of the fat pointer
   that obtained the array pointer.

   Accordingly, when looking for the object to substitute in place of
   a PLACEHOLDER_EXPR, we look down the first operand of the expression
   passed as the second operand to WITH_RECORD_EXPR until we find something
   of the desired type or reach a constant.  */

/* Denotes a record to later be supplied with a WITH_RECORD_EXPR when
   evaluating this expression.  The type of this expression is used to
   find the record to replace it.  */
DEFTREECODE (PLACEHOLDER_EXPR, "placeholder_expr", "x", 0)

/* Provide an expression that references a record to be used in place
   of a PLACEHOLDER_EXPR.  The record to be used is the record within
   operand 1 that has the same type as the PLACEHOLDER_EXPR in
   operand 0.  */
DEFTREECODE (WITH_RECORD_EXPR, "with_record_expr", "e", 2)

/* Simple arithmetic.  Operands must have the same machine mode
   and the value shares that mode.  */
DEFTREECODE (PLUS_EXPR, "plus_expr", "2", 2)
DEFTREECODE (MINUS_EXPR, "minus_expr", "2", 2)
DEFTREECODE (MULT_EXPR, "mult_expr", "2", 2)

/* Division for integer result that rounds the quotient toward zero.  */
/* Operands must have the same machine mode.
   In principle they may be real, but that is not currently supported.
   The result is always fixed point, and it has the same type as the
   operands if they are fixed point.   */
DEFTREECODE (TRUNC_DIV_EXPR, "trunc_div_expr", "2", 2)

/* Division for integer result that rounds the quotient toward infinity.  */
DEFTREECODE (CEIL_DIV_EXPR, "ceil_div_expr", "2", 2)

/* Division for integer result that rounds toward minus infinity.  */
DEFTREECODE (FLOOR_DIV_EXPR, "floor_div_expr", "2", 2)

/* Division for integer result that rounds toward nearest integer.  */
DEFTREECODE (ROUND_DIV_EXPR, "round_div_expr", "2", 2)

/* Four kinds of remainder that go with the four kinds of division.  */
DEFTREECODE (TRUNC_MOD_EXPR, "trunc_mod_expr", "2", 2)
DEFTREECODE (CEIL_MOD_EXPR, "ceil_mod_expr", "2", 2)
DEFTREECODE (FLOOR_MOD_EXPR, "floor_mod_expr", "2", 2)
DEFTREECODE (ROUND_MOD_EXPR, "round_mod_expr", "2", 2)

/* Division for real result.  The two operands must have the same type.
   In principle they could be integers, but currently only real
   operands are supported.  The result must have the same type
   as the operands.  */
DEFTREECODE (RDIV_EXPR, "rdiv_expr", "2", 2)

/* Division which is not supposed to need rounding.
   Used for pointer subtraction in C.  */
DEFTREECODE (EXACT_DIV_EXPR, "exact_div_expr", "2", 2)

/* Conversion of real to fixed point: four ways to round,
   like the four ways to divide.
   CONVERT_EXPR can also be used to convert a real to an integer,
   and that is what is used in languages that do not have ways of
   specifying which of these is wanted.  Maybe these are not needed.  */
DEFTREECODE (FIX_TRUNC_EXPR, "fix_trunc_expr", "1", 1)
DEFTREECODE (FIX_CEIL_EXPR, "fix_ceil_expr", "1", 1)
DEFTREECODE (FIX_FLOOR_EXPR, "fix_floor_expr", "1", 1)
DEFTREECODE (FIX_ROUND_EXPR, "fix_round_expr", "1", 1)

/* Conversion of an integer to a real.  */
DEFTREECODE (FLOAT_EXPR, "float_expr", "1", 1)

/* Exponentiation.  Operands may have any types;
   constraints on value type are not known yet.  */
DEFTREECODE (EXPON_EXPR, "expon_expr", "2", 2)

/* Unary negation.  Value has same type as operand.  */
DEFTREECODE (NEGATE_EXPR, "negate_expr", "1", 1)

DEFTREECODE (MIN_EXPR, "min_expr", "2", 2)
DEFTREECODE (MAX_EXPR, "max_expr", "2", 2)
DEFTREECODE (ABS_EXPR, "abs_expr", "1", 1)
DEFTREECODE (FFS_EXPR, "ffs_expr", "1", 1)

/* Shift operations for shift and rotate.
   Shift is supposed to mean logical shift if done on an
   unsigned type, arithmetic shift on a signed type.
   The second operand is the number of bits to
   shift by, and must always have mode SImode.
   The result has the same mode as the first operand.  */
DEFTREECODE (LSHIFT_EXPR, "alshift_expr", "2", 2)
DEFTREECODE (RSHIFT_EXPR, "arshift_expr", "2", 2)
DEFTREECODE (LROTATE_EXPR, "lrotate_expr", "2", 2)
DEFTREECODE (RROTATE_EXPR, "rrotate_expr", "2", 2)

/* Bitwise operations.  Operands have same mode as result.  */
DEFTREECODE (BIT_IOR_EXPR, "bit_ior_expr", "2", 2)
DEFTREECODE (BIT_XOR_EXPR, "bit_xor_expr", "2", 2)
DEFTREECODE (BIT_AND_EXPR, "bit_and_expr", "2", 2)
DEFTREECODE (BIT_ANDTC_EXPR, "bit_andtc_expr", "2", 2)
DEFTREECODE (BIT_NOT_EXPR, "bit_not_expr", "1", 1)

/* Combination of boolean values or of integers considered only
   as zero or nonzero.  ANDIF and ORIF allow the second operand
   not to be computed if the value of the expression is determined
   from the first operand.  AND, OR, and XOR always compute the second
   operand whether its value is needed or not (for side effects).  */
DEFTREECODE (TRUTH_ANDIF_EXPR, "truth_andif_expr", "e", 2)
DEFTREECODE (TRUTH_ORIF_EXPR, "truth_orif_expr", "e", 2)
DEFTREECODE (TRUTH_AND_EXPR, "truth_and_expr", "e", 2)
DEFTREECODE (TRUTH_OR_EXPR, "truth_or_expr", "e", 2)
DEFTREECODE (TRUTH_XOR_EXPR, "truth_xor_expr", "e", 2)
DEFTREECODE (TRUTH_NOT_EXPR, "truth_not_expr", "e", 1)

/* Relational operators.
   `EQ_EXPR' and `NE_EXPR' are allowed for any types.
   The others are allowed only for integer (or pointer or enumeral)
   or real types.
   In all cases the operands will have the same type,
   and the value is always the type used by the language for booleans.  */
DEFTREECODE (LT_EXPR, "lt_expr", "<", 2)
DEFTREECODE (LE_EXPR, "le_expr", "<", 2)
DEFTREECODE (GT_EXPR, "gt_expr", "<", 2)
DEFTREECODE (GE_EXPR, "ge_expr", "<", 2)
DEFTREECODE (EQ_EXPR, "eq_expr", "<", 2)
DEFTREECODE (NE_EXPR, "ne_expr", "<", 2)

/* Operations for Pascal sets.  Not used now.  */
DEFTREECODE (IN_EXPR, "in_expr", "2", 2)
DEFTREECODE (SET_LE_EXPR, "set_le_expr", "<", 2)
DEFTREECODE (CARD_EXPR, "card_expr", "1", 1)
DEFTREECODE (RANGE_EXPR, "range_expr", "2", 2)

/* Represents a conversion of type of a value.
   All conversions, including implicit ones, must be
   represented by CONVERT_EXPR nodes.  */
DEFTREECODE (CONVERT_EXPR, "convert_expr", "1", 1)

/* Represents a conversion expected to require no code to be generated.  */
DEFTREECODE (NOP_EXPR, "nop_expr", "1", 1)

/* Value is same as argument, but guaranteed not an lvalue.  */
DEFTREECODE (NON_LVALUE_EXPR, "non_lvalue_expr", "1", 1)

/* Represents something we computed once and will use multiple times.
   First operand is that expression.  Second is the function decl
   in which the SAVE_EXPR was created.  The third operand is the RTL,
   nonzero only after the expression has been computed.  */
DEFTREECODE (SAVE_EXPR, "save_expr", "e", 3)

/* Represents something whose RTL has already been expanded
   as a sequence which should be emitted when this expression is expanded.
   The first operand is the RTL to emit.  It is the first of a chain of insns.
   The second is the RTL expression for the result.  */
DEFTREECODE (RTL_EXPR, "rtl_expr", "e", 2)

/* & in C.  Value is the address at which the operand's value resides.
   Operand may have any mode.  Result mode is Pmode.  */
DEFTREECODE (ADDR_EXPR, "addr_expr", "e", 1)

/* Non-lvalue reference or pointer to an object.  */
DEFTREECODE (REFERENCE_EXPR, "reference_expr", "e", 1)

/* Operand is a function constant; result is a function variable value
   of typeEPmode.  Used only for languages that need static chains.  */
DEFTREECODE (ENTRY_VALUE_EXPR, "entry_value_expr", "e", 1)

/* Given two real or integer operands of the same type,
   returns a complex value of the corresponding complex type.  */
DEFTREECODE (COMPLEX_EXPR, "complex_expr", "2", 2)

/* Complex conjugate of operand.  Used only on complex types.
   The value has the same type as the operand.  */
DEFTREECODE (CONJ_EXPR, "conj_expr", "1", 1)

/* Used only on an operand of complex type, these return
   a value of the corresponding component type.  */
DEFTREECODE (REALPART_EXPR, "realpart_expr", "1", 1)
DEFTREECODE (IMAGPART_EXPR, "imagpart_expr", "1", 1)

/* Nodes for ++ and -- in C.
   The second arg is how much to increment or decrement by.
   For a pointer, it would be the size of the object pointed to.  */
DEFTREECODE (PREDECREMENT_EXPR, "predecrement_expr", "e", 2)
DEFTREECODE (PREINCREMENT_EXPR, "preincrement_expr", "e", 2)
DEFTREECODE (POSTDECREMENT_EXPR, "postdecrement_expr", "e", 2)
DEFTREECODE (POSTINCREMENT_EXPR, "postincrement_expr", "e", 2)

/* These types of expressions have no useful value,
   and always have side effects.  */

/* A label definition, encapsulated as a statement.
   Operand 0 is the LABEL_DECL node for the label that appears here.
   The type should be void and the value should be ignored.  */
DEFTREECODE (LABEL_EXPR, "label_expr", "s", 1)

/* GOTO.  Operand 0 is a LABEL_DECL node.
   The type should be void and the value should be ignored.  */
DEFTREECODE (GOTO_EXPR, "goto_expr", "s", 1)

/* RETURN.  Evaluates operand 0, then returns from the current function.
   Presumably that operand is an assignment that stores into the
   RESULT_DECL that hold the value to be returned.
   The operand may be null.
   The type should be void and the value should be ignored.  */
DEFTREECODE (RETURN_EXPR, "return_expr", "s", 1)

/* Exit the inner most loop conditionally.  Operand 0 is the condition.
   The type should be void and the value should be ignored.  */
DEFTREECODE (EXIT_EXPR, "exit_expr", "s", 1)

/* A loop.  Operand 0 is the body of the loop.
   It must contain an EXIT_EXPR or is an infinite loop.
   The type should be void and the value should be ignored.  */
DEFTREECODE (LOOP_EXPR, "loop_expr", "s", 1)

/*
Local variables:
mode:c
version-control: t
End:
*/