unw_get_fpreg man page

unw_get_fpreg -- get contents of floating-point register

Synopsis

#include <libunwind.h>

int unw_get_fpreg(unw_cursor_t *cp, unw_regnum_t reg, unw_fpreg_t *valp);

Description

The unw_get_fpreg() routine reads the value of floating-point  register reg in the stack frame identified by cursor cp and stores the value in the variable pointed to by valp.

The register numbering is target-dependent and described in separate  manual pages (e.g., libunwind-ia64(3) for the IA-64 target).  Furthermore, the exact set of accessible registers may depend on the  type of frame that cp is referring to. For ordinary stack  frames, it is normally possible to access only the preserved  (“callee-saved”) registers and frame-related registers (such as the  stack-pointer). However, for signal frames (see  unw_is_signal_frame(3)), it is usually possible to access  all registers.

Note that unw_get_fpreg() can only read the contents of  floating-point registers. See unw_get_fpreg(3) for a way to  read registers which fit in a single word.

Return Value

On successful completion, unw_get_fpreg() returns 0.  Otherwise the negative value of one of the error-codes below is  returned.

Thread and Signal Safety

unw_get_fpreg() is thread-safe as well as safe to use  from a signal handler.

Errors

UNW_EUNSPEC

An unspecified error occurred.

UNW_EBADREG

An attempt was made to read a register  that is either invalid or not accessible in the current frame.

In addition, unw_get_fpreg() may return any error returned by  the access_mem(), access_reg(), and  access_fpreg() call-backs (see  unw_create_addr_space(3)).

See Also

libunwind(3), libunwind-ia64(3), unw_get_reg(3), unw_is_fpreg(3), unw_is_signal_frame(3), unw_set_fpreg(3)

Author

David Mosberger-Tang
Email: dmosberger@gmail.com
WWW: http://www.nongnu.org/libunwind/.

Referenced By

libunwind(3), unw_get_reg(3), unw_is_fpreg(3), unw_is_signal_frame(3), unw_set_fpreg(3).

16 August 2007 Programming Library