9.15.2 x86 specific Directives

.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.