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Re: Proposed targets to deprecate for 3.4

Nathanael, are you interested in coordinating the development of the
obsoleted targets list for this cycle?  I'll be quite happy to let you
do it. ;-)

(Note preferred terminology - "obsoleted" not "deprecated")

You might find this chart of interest.  I was meaning to follow it up
with a similar chart of properties for individual targets but I ran
out of spare time.


--- arch-obs-criteria.txt ---

I've begun to compile a giant table of criteria for deciding whether
or not any given architecture should be preserved.  The table lists
desirable characteristics for all architectures supported by gcc.
Each characteristic has a unique letter.  In all cases, a letter
appearing is the desirable case; no letter is the undesirable case;
and a question mark means I don't know whether the architecture has
the characteristic or not.

Characteristics describing fundamental properties of the architecture
or target use CAPITAL LETTERS; characteristics describing properties
of the GCC port to that architecture or target use small letters.

Yes, many of these things are quite trivial.

Architectures are identified by their gcc/config subdirectory, *not*
their CPU field in config.guess output.

Architecture characteristic key
H       A hardware implementation exists.
M       A hardware implementation is currently being manufactured.
S       A Free simulator exists.
L       Integer registers are at least 32 bits wide.
Q       Integer registers are at least 64 bits wide.
N       Memory is byte addressable and bytes are eight bits.
F       Floating point arithmetic is supported
        (not necessarily by all implementations)
I       IEEE floating point is supported
        (possibly with software assistance for full conformance)
C       Architecture does not have a single condition code register.
B       Architecture does not have delay slots.
D       Architecture has a stack that grows downward.

l       Port can use ILP32 mode integer arithmetic.
q       Port can use LP64 mode integer arithmetic.
r       Port can switch between ILP32 and LP64 at runtime.
        (Not necessarily supported by all subtargets.)
c       Port does not use cc0.
p       Port does not use define_peephole.
f       Port defines prologue and/or epilogue RTL expanders.
g       Port does not define TARGET_ASM_FUNCTION_(PRO|EPI)LOGUE.
m       Port uses define_constants.
b       Port does not use '"* ..."' notation for output template code.
d       Port uses DFA scheduler descriptions.
h       Port does not contain old scheduler descriptions.
a       Port generates multiple inheritance thunks using
t       All insns either produce exactly one assembly instruction, or
        trigger a define_split.
e       <arch>-elf is a supported target.
s       <arch>-elf is the correct target to use with the simulator
        in /cvs/src.

         | Characteristics
Target   | HMSLQNFICBD lqrcpfgmbdhates
alpha    | H??LQNFICBD lq cpfgmbdha
arc      | ???L N    D l  cp        e
arm      | HMSL NFI BD l  c f m dha es
avr      | H??  N   BD           h  e
c4x      | H??L  F     l  c fgm    t
cris     | ???L N    D l         ha e
d30v     | ??SL N  CBD l  cpf       es
dsp16xx  | ???      B
fr30     | ??SL N    D l  c fg   h tes
frv      | ??SL NFI  D l  cpf m dha es
h8300    | ??SL N   BD l   pf m  h  e
i370     | H ?L NF  B  l   p     h
i386     | HM?LQNFI BD lq cpf m d a e
i860     | H ?L NFI BD l   p  m  h
i960     | H SL NFI B  l  c       a
ia64     | HM?LQNFICBD lqrcpf m dha e
ip2k     | ???  N   BD         b h  e
iq2000   | ???L N  C D l  cpfgm    te
m32r     | ??SL N   BD l  c f       es
m68hc11  | ??S  N   BD      f m  h tes
m68k     | HM?L NFI BD l      m  ha e
mcore    | H?SL N   BD l  c fg      es
mips     | HMSLQNFIC D lqrc f mbd   es
mmix     |   SLQNFICBD lq cpf mb ha
mn10300  | ??SL NFI BD l    fgm  h  es
ns32k    | H ?L NFI BD l         h
pa       | HM?LQNFIC   lqrc f   dha
pdp11    | H ?  NF  BD     p     h
rs6000   | HMSLQNFI BD lqrc f m dha e
s390     | HM?LQNFI BD lqrcpfgmbd a
sh       | HMSLQNFIC D lqrc f m d a e
sparc    | HMSLQNFI  D lqrc f mbdha e
stormy16 | ???  N  CB     cpf    hate
v850     | ??SL N   BD l   pfg      es
vax      | H ?L NF  BD l   pf m  ha
xtensa   | HM?L NFICBD l  cpf mb    e

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