on responsible for this behavior seems to be
>> resource_conflicts_p in reorg.c. Sadly, I could not find any
>> comments
>> explaining why volatile accesses cannot be put into delay slots.
>>
>> What is the reason for this behavior? I am unable to think of any
cts_p in reorg.c. Sadly, I could not find any
> comments
> explaining why volatile accesses cannot be put into delay slots.
>
> What is the reason for this behavior? I am unable to think of any
> situation where allowing volatile memory accesses in branch delay
> slots leads
ion where allowing volatile memory accesses in branch delay slots
> leads to problems. Am I missing a case? Or are negative effects limited
> to other architectures?
Delay slot filling is a code movement optimization and such optimizations are
not valid for volatile memory accesses in the
esses cannot be put into delay slots.
What is the reason for this behavior? I am unable to think of any
situation where allowing volatile memory accesses in branch delay slots
leads to problems. Am I missing a case? Or are negative effects limited
to other architectures?
Regards,
Jakob
--
e no
> instructions which can be used to fill the branch delay slots. My
> first idea was to convert these control-flow cf to SEQUENCE(cf) and
> hope the GCC will invoke DBR_OUTPUT_SEQEND(), but it does not? My
> second idea was to add these NOP-instructions: SEQUENCE(cf,
>
Hi!
I have to insert NOP-instructions into the insn-stream in my back-
end. I do this with something ala emit_insn_after(gen_nop, xyz). This
works so far.
GCC leaves control-flow operations as they are, if it there are no
instructions which can be used to fill the branch delay slots. My
Boris Boesler <[EMAIL PROTECTED]> writes:
> 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 sl
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 candidat
> 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
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
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