(Oracle Solaris) This option causes the driver to include a special mapfile on the link line. The mapfile aligns the text, data, and bss segments to the value specified by n. When using very large pages, it is important that the heap and stack segments are aligned on an appropriate boundary. If these segments are not aligned, small pages will be used up to the next boundary, which could cause a performance degradation. The mapfile ensures that the segments are aligned on an appropriate boundary.
The n value must be one of the following:
SPARC: The following values are valid: 8K, 64K, 512K, 2M, 4M, 32M, 256M, 1G, and none.
x86: The following values are valid: 4K, 8K, 64K, 512K, 2M, 4M, 32M, 256M, 1G, and none.
The default for both SPARC and x86 is none.
Recommended usage is as follows:
SPARC 32-bit compilation: -xsegment_align=64K SPARC 64-bit compilation: -xsegment_align=4M x86 32-bit compilation: -xsegment_align=8K x86 64-bit compilation: -xsegment_align=4M
The driver will include the appropriate mapfile. For example, if the user specifies -xsegment_align=4M, the driver adds -M install-directory/lib/compilers/mapfiles/map.4M.align to the link line, where install-directory is the installation directory. The aforementioned segments will then be aligned on a 4M boundary.