opcodes: aarch64: add flags to denote subclasses of ldst insns
The existing iclass information tells us the general shape and purpose
of the instructions. In some cases, however, we need to further disect
the iclass on the basis of other finer-grain information. E.g., for the
purpose of SCFI, we need to know whether a given insn with iclass
of ldst_* is a load or a store.
At the moment, specify subclasses for only those iclasses relevant to
SCFI: ldst_imm9, ldst_pos, ldstpair_indexed, ldstpair_off and
ldstnapair_offs.
Some insns are best tagged with F_SUBCLASS_OTHER rather than F_LDST_LOAD
or F_LDST_STORE:
- stg* ops (as they store tag only),
- prfm,
- ldpsw, ldrsw (32-bit loads with signed extended value. Not useful
for restore operations in context of SCFI.)
- Use F_SUBCLASS_OTHER for all QL_LDST_R8 and QL_LDST_R16 operands.
Also use F_SUBLASS_OTHER for strb/ldrb, strh/ldrh opcodes.
These are not full loads and stores and cannot be allowed for
register save / restore for the purpose of SCFI.
opcodes/
* aarch64-tbl.h: Use the new F_LDST_* flags.
1 file changed
