Literal Directive - Using as
Description: Using as

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##### 9.46.5.4 literal

The `.literal` directive is used to define literal pool data, i.e., read-only 32-bit data accessed via `L32R` instructions.

             .literal label, value[, value...]

This directive is similar to the standard `.word` directive, except that the actual location of the literal data is determined by the assembler and linker, not by the position of the `.literal` directive. Using this directive gives the assembler freedom to locate the literal data in the most appropriate place and possibly to combine identical literals. For example, the code:

             entry sp, 40
             .literal .L1, sym
             l32r    a4, .L1

can be used to load a pointer to the symbol `sym` into register `a4`. The value of `sym` will not be placed between the `ENTRY` and `L32R` instructions; instead, the assembler puts the data in a literal pool.

Literal pools are placed by default in separate literal sections; however, when using the ‘`--text-section-literals`’ option (see Command Line Options), the literal pools for PC-relative mode `L32R` instructions are placed in the current section.1 These text section literal pools are created automatically before `ENTRY` instructions and manually after ‘`.literal_position`’ directives (see literal_position). If there are no preceding `ENTRY` instructions, explicit `.literal_position` directives must be used to place the text section literal pools; otherwise, `as` will report an error.

When literals are placed in separate sections, the literal section names are derived from the names of the sections where the literals are defined. The base literal section names are `.literal` for PC-relative mode `L32R` instructions and `.lit4` for absolute mode `L32R` instructions (see absolute-literals). These base names are used for literals defined in the default `.text` section. For literals defined in other sections or within the scope of a `literal_prefix` directive (see literal_prefix), the following rules determine the literal section name:

1. If the current section is a member of a section group, the literal section name includes the group name as a suffix to the base `.literal` or `.lit4` name, with a period to separate the base name and group name. The literal section is also made a member of the group.
2. If the current section name (or `literal_prefix` value) begins with “`.gnu.linkonce.`kind`.`”, the literal section name is formed by replacing “`.`kind” with the base `.literal` or `.lit4` name. For example, for literals defined in a section named `.gnu.linkonce.t.func`, the literal section will be `.gnu.linkonce.literal.func` or `.gnu.linkonce.lit4.func`.
3. If the current section name (or `literal_prefix` value) ends with `.text`, the literal section name is formed by replacing that suffix with the base `.literal` or `.lit4` name. For example, for literals defined in a section named `.iram0.text`, the literal section will be `.iram0.literal` or `.iram0.lit4`.
4. If none of the preceding conditions apply, the literal section name is formed by adding the base `.literal` or `.lit4` name as a suffix to the current section name (or `literal_prefix` value).

#### Footnotes

[1] Literals for the `.init` and `.fini` sections are always placed in separate sections, even when ‘`--text-section-literals`’ is enabled.