UNW_GET_FPREG(3)
NAME
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/.