https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103395
Jakub Jelinek <jakub at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |fche at redhat dot com
--- Comment #9 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
CCing Frank as this is systemtap sys/sdt.h
which has:
# ifndef STAP_SDT_ARG_CONSTRAINT
# if defined __powerpc__
# define STAP_SDT_ARG_CONSTRAINT nZr
# else
# define STAP_SDT_ARG_CONSTRAINT nor
# endif
# endif
All of n, o and r are generic constraints and const0_rtx is valid for the "n"
constraint, so why is the backend trying to put it into memory at all?
What is systemtap trying to do is not use those operands in any instruction,
but note for the debugger how to find out the value of the asm input operand
(read some register, some memory or the immediate constant).
