This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Use predicates for RTL objects


Hi,
I have posted a patch series [1] for converting some of the RTL code to
use predicate macros, as described in the suggestions for beginner GCC
projects [2]. Segher was kind enough to give some comments on the
initial posting [3].

The code has been bootstrapped natively on x86_64, and I have built
cross-compilers for all targets except tilegx which gave build errors
even on trunk. The compiler object files are identical with trunk except
for *-checksum.o and string tables in build/gen*.o which change from
GET_CODE (..) == .. etc to the predicate macro.

Not all possible changes have been made yet, I figured I'd send this out
to check first.

I am hoping one of the maintainers will be able to take some time to
review the patches -- a few are quite large but are mechanical.

I would also like to get some comments on the following idea to make the
code checks more readable: I am thinking of adding
	bool rtx_def::is_a (enum rtx_code) const
This would allow us to make all the rtx_code comparisons more readable
without having to define individual macros for each.
i.e.,
	REG_P (x)			   => x->is_a (REG)
	GET_CODE (x) == PLUS		   => x->is_a (PLUS)
	GET_CODE (PATTERN (x)) == SEQUENCE => PATTERN (x)->is_a (SEQUENCE)

More complex predicates could be left as macros or additional methods
could be defined like rtx_def::is_a_nondebug_insn etc. I think this
should mostly be an improvement, although the comparisons around INSN
may become slightly more confusing: currently, INSN_P (x) is different
from is_a <rtx_insn *> (x), and using something like x->is_a_insn () for
the former would probably increase confusion.

Thanks.

[1] https://gcc.gnu.org/ml/gcc-patches/2019-08/msg00327.html
[2] https://gcc.gnu.org/projects/beginner.html
[3] https://gcc.gnu.org/ml/gcc-patches/2019-08/msg00171.html


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]