[Patch] libffi-MIPS: More n64 fixes.
Fri Dec 7 10:32:00 GMT 2007
David Daney <firstname.lastname@example.org> writes:
> As with my patch from yesterday, this patch fixes several failures in
> the libffi testsuite caused by the use of a 32 bit add instruction on a
> 64 bit pointer value causing the upper 32 bits to be clobbered. At the
> same time I took the liberty of converting several 'add a,b,0' to 'move
> a,b'. Although these were not causing any immediate problems, I think
> it makes the code more understandable.
Agreed. It also saves worrying about whether the value we're moving
is really a 32-bit one. However, I couldn't help noticing that all
the moves could be folded into neighbouring instructions. E.g.:
REG_L t4, 3*FFI_SIZEOF_ARG($fp) # load the flags word
move t6, t4 # and copy it into t6
and t4, ((1<<FFI_FLAG_BITS)-1)
REG_L t6, 3*FFI_SIZEOF_ARG($fp) # load the flags word
and t4, t6, ((1<<FFI_FLAG_BITS)-1)
while things like:
move t4, t6
SRL t4, 1*FFI_FLAG_BITS
SRL t4, t6, 1*FFI_FLAG_BITS
As well as being more efficient, it seems slightly more readable
(at least to me).
OK with that change, thanks.
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