-f

Align data in COMMON blocks.

SPARC: 77/90

Align double- and quad-precision data in COMMON blocks.

This flag changes the data layout in COMMON blocks (and EQUIVALENCE classes): double- and quad-precision data in COMMON blocks and EQUIVALENCE classes are laid out in memory along their "natural" alignment, which is on 8-byte boundaries (or on 16-byte boundaries for quad-precision when compiling for 64-bit environments with -xarch=v9 or v9a). The default alignment of data in COMMON blocks is on 4-byte boundaries.

-f may result in nonstandard alignment of data, which could cause problems with variables in EQUIVALENCE or COMMON and may render the program non-portable if -f is required.

Using -dbl with -f aligns all 64-bit integer data on 8-byte boundaries as well.

Compiling any part of a program with -f requires compiling all subprograms of that program with -f.

By itself, this option does not enable the compiler to generate faster multi-word fetch/store instructions on double and quad precision data. The -dalign option does this and invokes -f as well. Use of -dalign is preferred over the older -f. See -dalign, "-dalign". Because -dalign is part of the -fast option, so is -f.