Summary:
This directive is used for setting up $gp in the beginning of a function.
It expands to three instructions if PIC is enabled:
lui $gp, %hi(_gp_disp)
addui $gp, $gp, %lo(_gp_disp)
addu $gp, $gp, $reg
_gp_disp is a special symbol that the linker sets to the distance between
the lui instruction and the context pointer (_gp).
Reviewers: dsanders
Reviewed By: dsanders
Differential Revision: http://reviews.llvm.org/D3480
llvm-svn: 207637
