The following alphabetical list defines the stack unwind directive operands listed in the table Stack Unwind Directives:
ar.pfs, ar.unat, and ar.lc are explicit register names.
br-location is the alternative branch register used to get the return link. By default, b0 is the return link.
ecount is the number of prologues -1 specified by the assembler if this field is not specified by the user.
gr-location is a general-purpose register that specifies the destination of the save operation. For example, registers r1 and loc1.
grsave saves the rp, ar.pfs, psp, and pr register contents to the first general-purpose register.
imm-location (immediate location) is the offset between the sp or psp, and the save_address, specified in bytes. This offset is always positive and specified as follows:
imm-mask (immediate mask) is an integer constant specifying a bit pattern for the preserved registers, as follows:
— The immediate mask (imm-mask)
of the .prologue
directive is specified as follows:
rp (return link) (bit 3), ar.pfs
register (bit 2), psp
(previous
stack pointer) (bit 1), pr
register (bit 0)
— The immediate mask (imm-frmask) of the .save.f and .save.gf directives refer to the preserved floating-point registers.
— The immediate mask (imm-grmask) of the .save.g and .save.gf directives refer to the preserved general registers.
— The immediate mask (imm-brmask) of the .save.b directive refers to the preserved branch registers.
os-type is one of @svr4, @hpux, or @nt. It specifies the operating system type.
phases is the number of phases, ranging from 0 to 3.
pr is an explicit register name.
@priunat is a predefined symbol and indicates a primary unat.
psp is the location of the previous stack frame.
psp_offset: imm-location = psp_address - save_address. See also imm-mask.
qp is one of the following predicate registers: p1-p63.
reg is one of the following registers: r4-r7, f2-f5, f16-f31, b1-b5, pr, @psp, @priunat, rp, ar.bsp, ar.bspstore, ar.rnat, ar.unat, ar.fpsr, ar.pfs, or ar.lc.
rp is an explicit register name.
size is the fixed frame size in bytes.
sp is an explicit register name.
sp_offset: imm-location = save_address - sp_address. See also imm-mask.
state_no is the state copied or restored.
symbol is an assembly label.
tag is an optional operand, which specifies a "when" attribute of the operation described by the directive.
treg is one of the following registers: r1-r127, f2-f127, or b0-b7.