On 10/20/2016 11:22 AM, Bernd Schmidt wrote:
On 10/20/2016 01:49 AM, David Malcolm wrote:
(b) for all codes for which rtx_equal_p requires pointer equality, add
some kind of extra ID to the dump, allowing the loader to reconstruct
the graph. This could be the pointer itself:
(scratch:DI [0x7ffff19ee150])
(scratch:DI [ptr:0x7ffff19ee150])
or somesuch, but it would perhaps be better to use some kind of more
human-friendly ID e.g.
(scratch:DI [ptr-idx: 42])
or similar, rather than subject ourselves to raw hex values. Probably
need an extra flag to print-rtl.c, to avoid making the dumps more
verbose for everyone who doesn't want this (if so, does "compact" mode
need renaming...)
Or just do this for SCRATCH, maybe?
Recognizing by SCRATCH wouldn't catch everything, I believe. You should
be able to check n_dups and dup_loc in recog_data to identify cases
where you need to ensure something is restored with pointer equality.
I'd hope you already have pointer equality for all instances of each
pseudo register.
As for the output format, I think you're on the right track assigning
IDs, but maybe the following would be easier to parse for machines and
humans:
(cinsn (set (mem/v:BLK {0}(scratch:DI) [0 A8])
(unspec:BLK [
(mem/v:BLK (match_dup 0) [0 A8])
] UNSPEC_MEMORY_BLOCKAGE)) "test.c":2
(nil))
where the {0} could be recognized as a prefix saying "store the address
of the next rtx into slot 0, with a finalization pass replacing
match_dups with the corresponding address.
Could also maybe do something like (0|scratch:DI), that ought to also be
unambiguous.
Bernd
