Re: [PATCH 0/9] RFC: selftests based on RTL dumps

[Bernd Schmidt <bschmidt at redhat dot com>]

On 09/12/2016 08:57 PM, David Malcolm wrote:

> I'm not sure I follow - this sounds like a dedicated target for
> selftesting.
>
> Would it be a separate configuration i.e. something like:
>    ../src/configure --target=rtl-selftest
> or somesuch?

The way I imagine it working, the top-level Makefile would create a 
selftest-gcc/ subdirectory, and run a configure line much like the above 
inside it. It would live independently of the real compiler we're 
building in gcc/.

That's not something I'm deciding, it needs a broader consensus. But I 
feel pretty strongly that this is how things should be organized.

> > > +  const char *input_dump
> > > +    = ("(insn 8 0 9 2 (set (reg:DI 78)\n"
> > > +       "        (lshiftrt:DI (reg:DI 76)\n"
> > > +       "            (const_int 32 [0x20])))\n"
> > > +       "        ../../src/gcc/testsuite/gcc.dg/asr_div1.c:14\n"
> > > +       "        641 {*aarch64_lshr_sisd_or_int_di3}\n"
> > > +       "     (expr_list:REG_DEAD (reg:DI 76)\n"
> > > +       "        (nil)))\n"
> > > +       "(insn 9 8 0 2 (set (reg:SI 79)\n"
> > > +       "        (ashiftrt:SI (subreg:SI (reg:DI 78) 0)\n"
> > > +       "            (const_int 3 [0x3])))\n"
> > > +       "        ../../src/gcc/testsuite/gcc.dg/asr_div1.c:14\n"
> > > +       "        642 {*aarch64_ashr_sisd_or_int_si3}\n"
> > > +       "     (expr_list:REG_DEAD (reg:DI 78)\n"
> > > +       "        (nil)))\n");
> >
> > I can sort of see the desire to just copy&paste dumps into this, but
> > this strikes me as really ugly. Especially if we end up using real
> > targets this hard-codes not just pattern structure but also pattern
> > names, which I think is too great a burden on target maintainers.
>
> Note that the loader now resets INSN_CODE to -1, regardless of the
> actual code passed in, to force re-recognition, and to isolate the
> dumps somewhat from changes to the .md files.  So although the above
> says insn 641 and 642 (for some snapshot of the aarch64 md file), it
> gets reset to -1.

Best to find out a way to avoid including it in the strings then, to 
avoid confusion.


Bernd