Re: add h8sx support to h8300

[Alexandre Oliva <aoliva at redhat dot com>]

On Jul  8, 2004, Richard Sandiford <rsandifo@redhat.com> wrote:

> Alexandre Oliva <aoliva@redhat.com> writes:
>> +     - we would like 'D' to be be NO_REGS when the frame pointer isn't
>> +       live, but we the frame pointer may turn out to be needed after
>> +       we start reload, and then we may have already decided we don't
>> +       have a choice, so we can't do that.  Forcing the register
>> +       allocator to use er6 if possible might produce better code for
>> +       small functions: it's more efficient to save and restore er6 in
>> +       the prologue & epilogue than to do it in a define_split.
>> +       Hopefully disparaging 'D' will have a similar effect, without
>> +       forcing a reload failure if the frame pointer is found to be
>> +       needed too late.  */

> Not sure I understand this.  Do you have a testcase?

gcc.c-torture/execute/builtin-setjmp.c.  It *still* fails at -O3
-fomit-frame-pointer, but not at lower optimization levels, which it
did before.

-- 
Alexandre Oliva             http://www.ic.unicamp.br/~oliva/
Red Hat Compiler Engineer   aoliva@{redhat.com, gcc.gnu.org}
Free Software Evangelist  oliva@{lsd.ic.unicamp.br, gnu.org}