Call frame information directives for common blocks

In this section:

Common block directives:

CFI COMMON name USING namesblock

CFI ENDCOMMON name

CFI CODEALIGN codealignfactor

CFI DATAALIGN dataalignfactor

CFI DEFAULT { UNDEFINED | SAMEVALUE }

CFI RETURNADDRESS resource type

`codealignfactor`	The smallest common factor of all instruction sizes. Each CFI directive for a data block must be placed according to this alignment. 1 is the default and can always be used, but a larger value reduces the produced call frame information in size. The possible range is 1–256.
`commonblock`	The name of a previously defined common block.
`dataalignfactor`	The smallest common factor of all frame sizes. If the stack grows toward higher addresses, the factor is negative; if it grows toward lower addresses, the factor is positive. 1 is the default, but a larger value reduces the produced call frame information in size. The possible ranges are –256 to –1 and 1 to 256.
`name`	The name of the block.
`namesblock`	The name of a previously defined names block.
`resource`	The name of a resource.
`type`	The memory type, such as `CODE`, `CONST`, or `DATA`. In addition, any of the segment memory types supported by the linker. It is only used for denoting an address space.

Use these directives to define a common block:

Directive	Description
`CFI CODEALIGN`	Declares code alignment.
`CFI COMMON`	Starts or extends a common block.
`CFI DATAALIGN`	Declares data alignment.
`CFI DEFAULT`	Declares the default state of all resources.
`CFI ENDCOMMON`	Ends a common block.
`CFI RETURNADDRESS`	Declares a return address column.

Table 157. Call frame information directives common block

In addition to these directives you might also need the call frame information directives for specifying rules, or CFI expressions for resources and CFAs, see Call frame information directives for tracking resources and CFAs.

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