Am 12.12.2007 um 16:21 schrieb Ian Lance Taylor:
Boris Boesler <[EMAIL PROTECTED]> writes:
I "implemented" branch delay slots (define_delay) for my
architecture and I use the command line option -fdelayed-branch. But
branch delay slot filling is done just for a few candidates. Even for
the same rule within the same compilation unit (C file) it is done in
a few cases but not in all. How can this happen?
There are many possible reasons. The first step is to look at the
dump file generated by -fdump-rtl-dbr.
Could have thought of this myself ..
Ok, I think I found it: GCC leaves control-flow operations as they
are, if it can not place other operations in branch delay slots
(represented as SEQUENCEs in GCC); or in other words: GCC does not
represent empty delay slots.
Is this correct?
Boris
