- operand of mode MODE.
-
- It usually pays to define several simpler macros to serve as subroutines for
- this one. Otherwise it may be too complicated to understand.
-
- This macro must exist in two variants: a strict variant and a non-strict
- one. The strict variant is used in the reload pass. It must be defined so
- that any pseudo-register that has not been allocated a hard register is
- considered a memory reference. In contexts where some kind of register is
- required, a pseudo-register with no hard register must be rejected.
-
- The non-strict variant is used in other passes. It must be defined to
- accept all pseudo-registers in every context where some kind of register is
- required.
-
- Compiler source files that want to use the strict variant of this macro
- define the macro `REG_OK_STRICT'. You should use an `#ifdef REG_OK_STRICT'
- conditional to define the strict variant in that case and the non-strict
- variant otherwise.
-
- Subroutines to check for acceptable registers for various purposes (one for
- base registers, one for index registers, and so on) are typically among the
- subroutines used to define `GO_IF_LEGITIMATE_ADDRESS'. Then only these
- subroutine macros need have two variants; the higher levels of macros may be
- the same whether strict or not.
-
- Normally, constant addresses which are the sum of a `symbol_ref' and an
- integer are stored inside a `const' RTX to mark them as constant.
- Therefore, there is no need to recognize such sums specifically as
- legitimate addresses. Normally you would simply recognize any `const' as
- legitimate.
-
- Usually `PRINT_OPERAND_ADDRESS' is not prepared to handle constant sums that
- are not marked with `const'. It assumes that a naked `plus' indicates
- indexing. If so, then you *must* reject such naked constant sums as
- illegitimate addresses, so that none of them will be given to
- `PRINT_OPERAND_ADDRESS'.
-
- On some machines, whether a symbolic address is legitimate depends on the
- section that the address refers to. On these machines, define the macro
- `ENCODE_SECTION_INFO' to store the information into the `symbol_ref', and
- then check for it here. When you see a `const', you will have to look
- inside it to find the `symbol_ref' in order to determine the section.
-
- The best way to modify the name string is by adding text to the beginning,
- with suitable punctuation to prevent any ambiguity. Allocate the new name
- in `saveable_obstack'. You will have to modify `ASM_OUTPUT_LABELREF' to
- remove and decode the added text and output the name accordingly, and define
- `STRIP_NAME_ENCODING' to access the original name string.
-
- You can check the information stored here into the `symbol_ref' in the
- definitions of the macros `GO_IF_LEGITIMATE_ADDRESS' and
- `PRINT_OPERAND_ADDRESS'. */