Re: Rework subreg_get_info

[Richard Sandiford <richard dot sandiford at arm dot com>]

Joseph Myers <joseph@codesourcery.com> writes:
> On Tue, 15 Nov 2016, Richard Sandiford wrote:
>> Richard Sandiford <richard.sandiford@arm.com> writes:
>> > This isn't intended to change the behaviour, just rewrite the
>> > existing logic in a different (and hopefully clearer) way.
>> > The new form -- particularly the part based on the "block"
>> > concept -- is easier to convert to polynomial sizes.
>> >
>> > Tested on aarch64-linux-gnu and x86_64-linux-gnu.  OK to install?
>> 
>> Sorry, I should have said: this was also tested by compiling the
>> testsuite before and after the change at -O2 -ftree-vectorize on:
>> 
>>     aarch64-linux-gnueabi alpha-linux-gnu arc-elf arm-linux-gnueabi
>>     arm-linux-gnueabihf avr-elf bfin-elf c6x-elf cr16-elf cris-elf
>>     epiphany-elf fr30-elf frv-linux-gnu ft32-elf h8300-elf
>>     hppa64-hp-hpux11.23 ia64-linux-gnu i686-pc-linux-gnu
>>     i686-apple-darwin iq2000-elf lm32-elf m32c-elf m32r-elf
>>     m68k-linux-gnu mcore-elf microblaze-elf mips-linux-gnu
>>     mipsisa64-linux-gnu mmix mn10300-elf moxie-rtems msp430-elf
>>     nds32le-elf nios2-linux-gnu nvptx-none pdp11 powerpc-linux-gnu
>>     powerpc-eabispe powerpc64-linux-gnu powerpc-ibm-aix7.0 rl78-elf
>
> e500 double (both DFmode and TFmode) was the case that motivated the 
> original creation of subreg_get_info.  I think powerpc-linux-gnuspe 
> --enable-e500-double would be a good case for verifying the patch doesn't 
> change generated code.  (Though when I tried building it from mainline 
> sources last week I got an ICE in LRA building __multc3, so testing it 
> might be problematic at present.)

Thanks for the pointer.  I've now tried comparing the testsuite
output on that combination and there were no differences.  31 tests
triggered an internal compiler error but >17800 compiled successfully,
so hopefully the test was at least somewhat meaningful.

(For the record: I got a build failure due to addsi3 FAILing,
but I hacked around that by converting it to a force_reg/DONE.)

Thanks,
Richard