From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Frank Ch. Eigler" To: Doug Evans Cc: Richard Sandiford , cgen@sources.redhat.com Subject: Re: Endianness and CGEN_INT_INSN_P Date: Tue, 02 Jan 2001 14:10:00 -0000 Message-id: <20010102170954.K19510@redhat.com> References: <20010102114852.D19510@redhat.com> <14930.4668.100918.407447@casey.transmeta.com> X-SW-Source: 2001-q1/msg00008.html Hi - dje wrote: : [...] : > I must admit that I would prefer to see a single general mechanism : > (byte strings) as opposed to that PLUS a reasonable but tricky : > optimization. Doug, do you have any sense of how much processing : > time the INT_INSN_P flag saves when present? : : The intent was in part to save processing time, but not of GAS per se. That's true -- the simulators also like to pass instruction words around. : [...] : When I did INT_INSN_P I was thinking of the various RISC chips : that all have 32 bit insns, and I wanted cgen to be used in _all_ the : various apps where people were encoding and decoding insns : (not that that is the only intended use of cgen of course). But none of these (future / mythical?) applications would be precluded if byte-strings were the canonical representation, and the apps were to use to/from-int32 conversions. I'm arguing more from a software engineering perspective. By having the INT_INSN_P option, two forks of target support runtimes must be kept functional with changes such as variable-length instructions. Where the option is not a clear & convincing optimization that justifies the burden of dual maintenance, it should be deprecated. : [...] : refresher: libcgen is a (still mythical) generalized and spiffed up : libopcodes To me, an important requirement would be to support multiple targets concurrently. The fewer compile-time target-dependent macros (INT_INSN_P) the better. :-) - FChE -- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE6UlGyVZbdDOm/ZT0RAnNqAJ9jTwFiEVUTKZPNeNh0ACafsU4o1gCdE92D 1Zn68BNG1If6oahSXPJCneY= =hlg1 -----END PGP SIGNATURE-----