- ALLOCA_FRAME
Indicates that this procedure allocates temporary
storage by modifying the stack pointer (%r30).
A copy of the frame pointer is normally placed in %r3.
However, if this procedure also has a large frame (FRAME
> 8191), then
the copy of the frame pointer is placed in %r4
instead.
- ARGS_SAVED
Indicates that this procedure stores the arguments
into the stack frame.
- CALLER
or CALLS
Indicates that this procedure
calls other routines, so it requires space in the stack for a frame
marker and a fixed argument list. (When a program is assembled using
the -f option,
this becomes the default case.)
The Assembler allocates stack space when it encounters an
.ENTER pseudo-operation
and deallocates this space when it encounters a .LEAVE
pseudo-operation. The Assembler allocates 48 bytes for the PA-RISC
32-bit mode and 80 bytes for the PA-RISC 64-bit (2.0W) mode.
The frame marker and fixed argument list area occur at the
top of the stack so you must take this space into account when locating
local variables on the stack. You must allocate an area (using FRAME=)
for a variable argument list when this area is needed.
CALLER
does not imply the existence of the parameter SAVE_RP.
The CALLER
and CALLS parameters
are equivalent.
- NO_CALLS
Indicates that the procedure does not call other
procedures and, therefore, does not require a frame marker on the
stack. This is the default case unless the program is assembled
using the -f
option.
- CLEANUP
Indicates that this procedure requires cleanup during
unwind.
- ENTRY_FR= register
Specifies the high end boundary of the Entry/Save
floating-point register partition. The partition includes %fr12
through %fr15
for PA-RISC 1.0 and %fr12
through %fr21
for PA-RISC 1.1. The Assembler automatically saves these registers
when it encounters an .ENTER
pseudo-operation and restores them when it encounters a .LEAVE
pseudo-operation.
- ENTRY_GR= register
Specifies the high end boundary of the Entry/Save
register partition. The partition may extend over registers %r3
through %r18.
If you omit this parameter, no registers are saved.
When a procedure uses these registers, the Assembler saves
their values when it encounters an .ENTER
pseudo-operation and restores these values when it encounters a
.LEAVE pseudo-operation.
The called routine saves these registers upon entry and restores
them upon exit, so values in Entry/Save registers are preserved
across a procedure call.
Note: See the description of the FRAME
parameter regarding the use of %r3.
- ENTRY_SR= register
Specifies the high end boundary of the space register
partition. The partition currently contains only %sr3.
When the .CALLINFO
directive includes this parameter, the Assembler automatically saves
the Space Register when it encounters an .ENTER
pseudo-operation and restores this register when it encounters a
.LEAVE pseudo-operation.
- FRAME=number
Defines the combined size (in bytes) of the local
variable area and variable argument area needed by the procedure.
The .ENTER pseudo-operation
allocates the desired space for local variables below the frame
marker and the .LEAVE
pseudo-operation deallocates that space.
The number parameter must be a
multiple of eight bytes. If a .CALLINFO
directive lacks this parameter, the Assembler assumes a default
frame size of zero.
The stack frame includes space for local variables and the
variable argument area. The size specified for the frame should
not include space for the stack frame marker or the fixed argument
area. Allocation of these areas is controlled by the CALLER
and NO_CALLS
parameters. The inclusion of the CALLER
parameter always allocates space for the stack frame marker and
the fixed argument area. (See Table 4-1 “Assembler Directives”)
A frame marker is required if the assembly routine calls another
routine.
For PA-RISC 32-bit mode, the frame area is offset from the
Stack Pointer by 48 bytes because the frame marker contains 32 bytes
and the fixed argument list contains 16 bytes, when both of these
areas are present.
For PA-RISC 2.0W (64-bit mode), the frame area is offset from
the Stack Pointer by 80 bytes because the frame marker contains
16 bytes and the fixed argument list contains 64 bytes.
However, the Assembler does not allocate space for the frame
marker and fixed argument list if the procedure does not call any
other routines (see the NO_CALLS
parameter).
If the total frame size for a procedure exceeds 8191 bytes,
the Assembler uses %r3
to locate the previous frame marker when it encounters an .ENTER
or .LEAVE pseudo-operation.
Under these circumstances, changing the value of %r3
can cause serious consequences.
- HPUX_INT
Specifies that this procedure is an interrupt procedure.
This is necessary for the stack unwind mechanism.
- MILLICODE
Indicates to the unwind mechanism that this is a millicode
routine and it should follow the millicode calling conventions.
- NO_UNWIND
This is to be used only in the context of stand-alone
code or any procedure that does not need to be reliably
unwound.
- RP_IN_R31
Indicates that the return pointer has been moved
to register %r31 in order to make local millicode calls. This parameter
is only valid for the PA-RISC 2.0W (64-bit mode).
- SAVE_MRP
Indicates that this millicode procedure saves the Millicode
Return Pointer (MRP) in its frame marker at (SP-20).
- SAVE_RP
Specifies that the frame marker of the previous
routine stores the value of the Return Pointer (RP).
The Assembler automatically saves the Return Pointer when it encounters
an .ENTER pseudo-operation,
and it restores the RP
value when it encounters a .LEAVE
pseudo-operation. Generally, any procedure that calls other routines
should save the RP
value.
- SAVE_SP
Specifies that the current routine saves the value
of Previous_SP
in its frame marker at SP-4.
Because the Assembler does not automatically save the Stack Pointer
when it generates Entry/Exit code sequences, you must explicitly
save this value in your program when using this key word. You can
obtain the Previous_SP
value from the special register %previous_sp.
Programming languages, such as HP Pascal/HP-UX, typically
use this value for up-level display pointers to reference local
variables.
- SAVE_SR0
Indicates that this millicode procedure saves %sr0
in its frame marker at (SP-16).
This parameter is not valid for PA-RISC 2.0W (64-bit mode).
