-@findex CONST_COSTS
-@item CONST_COSTS (@var{x}, @var{code}, @var{outer_code})
-A part of a C @code{switch} statement that describes the relative costs
-of constant RTL expressions. It must contain @code{case} labels for
-expression codes @code{const_int}, @code{const}, @code{symbol_ref},
-@code{label_ref} and @code{const_double}. Each case must ultimately
-reach a @code{return} statement to return the relative cost of the use
-of that kind of constant value in an expression. The cost may depend on
-the precise value of the constant, which is available for examination in
-@var{x}, and the rtx code of the expression in which it is contained,
-found in @var{outer_code}.
-
-@var{code} is the expression code---redundant, since it can be
-obtained with @code{GET_CODE (@var{x})}.
-
-@findex RTX_COSTS
-@findex COSTS_N_INSNS
-@item RTX_COSTS (@var{x}, @var{code}, @var{outer_code})
-Like @code{CONST_COSTS} but applies to nonconstant RTL expressions.
-This can be used, for example, to indicate how costly a multiply
-instruction is. In writing this macro, you can use the construct
-@code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast
-instructions. @var{outer_code} is the code of the expression in which
-@var{x} is contained.
-
-This macro is optional; do not define it if the default cost assumptions
-are adequate for the target machine.
-
-@findex DEFAULT_RTX_COSTS
-@item DEFAULT_RTX_COSTS (@var{x}, @var{code}, @var{outer_code})
-This macro, if defined, is called for any case not handled by the
-@code{RTX_COSTS} or @code{CONST_COSTS} macros. This eliminates the need
-to put case labels into the macro, but the code, or any functions it
-calls, must assume that the RTL in @var{x} could be of any type that has
-not already been handled. The arguments are the same as for
-@code{RTX_COSTS}, and the macro should execute a return statement giving
-the cost of any RTL expressions that it can handle. The default cost
-calculation is used for any RTL for which this macro does not return a
-value.
-
-This macro is optional; do not define it if the default cost assumptions
-are adequate for the target machine.
-
-@findex ADDRESS_COST
-@item ADDRESS_COST (@var{address})
-An expression giving the cost of an addressing mode that contains
-@var{address}. If not defined, the cost is computed from
-the @var{address} expression and the @code{CONST_COSTS} values.
-
-For most CISC machines, the default cost is a good approximation of the
-true cost of the addressing mode. However, on RISC machines, all
-instructions normally have the same length and execution time. Hence
-all addresses will have equal costs.
-
-In cases where more than one form of an address is known, the form with
-the lowest cost will be used. If multiple forms have the same, lowest,
-cost, the one that is the most complex will be used.
-
-For example, suppose an address that is equal to the sum of a register
-and a constant is used twice in the same basic block. When this macro
-is not defined, the address will be computed in a register and memory
-references will be indirect through that register. On machines where
-the cost of the addressing mode containing the sum is no higher than
-that of a simple indirect reference, this will produce an additional
-instruction and possibly require an additional register. Proper
-specification of this macro eliminates this overhead for such machines.
-
-Similar use of this macro is made in strength reduction of loops.
-
-@var{address} need not be valid as an address. In such a case, the cost
-is not relevant and can be any value; invalid addresses need not be
-assigned a different cost.
-
-On machines where an address involving more than one register is as
-cheap as an address computation involving only one register, defining
-@code{ADDRESS_COST} to reflect this can cause two registers to be live
-over a region of code where only one would have been if
-@code{ADDRESS_COST} were not defined in that manner. This effect should
-be considered in the definition of this macro. Equivalent costs should
-probably only be given to addresses with different numbers of registers
-on machines with lots of registers.
-
-This macro will normally either not be defined or be defined as a
-constant.
-