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/.
