Hi,
I am currently working on adding native fixed-point support to the avr
backend. A lot of stuff is working, but there are a few things left,
one of them is conversions from fixed point to floating point.
I have conversions between all integer and fixed point types working
as well as SA to SF conversion.
I want to convert the fixed point types smaller than SA to float by
using define_split to convert to SA then to SF. I am first trying to
get QQ->SF working, one of the things I tried is:
(define_expand "fractqqsf2"
[(set (match_operand:SF 0 "register_operand" "")
(fract_convert:SF (match_operand:QQ 1 "register_operand" "")))
(clobber (match_operand:SA 2 "register_operand" ""))]
""
"")
(define_split
[(set (match_operand:SF 0 "register_operand" "")
(fract_convert:SF (match_operand:QQ 1 "register_operand" "")))
(clobber (match_operand:SA 2 "register_operand" ""))]
""
[(set (match_dup 2) (fract_convert:SA (match_dup 1)))
(set (match_dup 0) (fract_convert:SF (match_dup 2)))]
"")
This causes the compiler to crash with a segmentation fault. I have
tried a bunch of other strategies, and usually the compiler complains
about unrecognized instruction. I'm not sure what I'm doing wrong,
but I don't have a good reference example for this. I can implement
these routines in a library, that might end up being better in terms
of space, but I would like to know what I am doing wrong and how to
use define_split correctly.
Thanks,
Sean
