as: i386-Directives
9.15.2 x86 specific Directives
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'.lcomm SYMBOL , LENGTH[, ALIGNMENT]'
Reserve LENGTH (an absolute expression) bytes for a local common
denoted by SYMBOL. The section and value of SYMBOL are those of
the new local common. The addresses are allocated in the bss
section, so that at run-time the bytes start off zeroed. Since
SYMBOL is not declared global, it is normally not visible to 'ld'.
The optional third parameter, ALIGNMENT, specifies the desired
alignment of the symbol in the bss section.
This directive is only available for COFF based x86 targets.
'.largecomm SYMBOL , LENGTH[, ALIGNMENT]'
This directive behaves in the same way as the 'comm' directive
except that the data is placed into the .LBSS section instead of
the .BSS section 
Comm.
The directive is intended to be used for data which requires a
large amount of space, and it is only available for ELF based
x86_64 targets.
Info Catalog
as: i386-Options
as: i386-Dependent
as: i386-Syntax