Stack Frame Description - Analog Devices VISUALDSP++ 3.5 Manual

For increased efficiency the ADSP-219x DSP run-time model assumes 32
words past the stack pointer are available for use within a leaf function
(functions that make no calls) and are protected from changes by an inter-
rupt handler. This provides easy access to temporary space for use within
simple leaf functions without the overhead of establishing a stack frame.

Stack Frame Description

This section describes the stack, as shown in
Incoming Arguments
The memory area for incoming arguments begins at the
+ . Argument words are mapped by ascending addresses, so the sec-
1
ond argument word is mapped at
Linkage Information
The return address is saved on the hardware stack by the
instruction. In the called function, the address can then be popped
from the hardware stack and saved as part of the stack frame. This
information is used by the debugger to generate call stack debug
information for source level debugging. Saving the return address
on the stack frame is also useful in avoiding overflowing the finite
hardware call stack, when using recursion for example. The value
stored on the stack gets pushed back on the hardware call stack
before the return of the function. The compiler detects recursive
routines and also offers a switch to avoid overflowing the hardware
call stack, called
for highly nested software.
Local Variables and Temporaries
Space for a register save area and local variables/temporaries is allo-
cated on the stack by the function prologue. Local variables and
temporaries are typically placed first in this area so they can be
VisualDSP++ 3.5 C/C++ Compiler and Library Manual
for ADSP-219x DSPs
FP+2
-no_hardware_pc_stack
Compiler
Figure 1-3 on page
.
, which might be required
1-156.
value
FP
CALL
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