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# BITFIELDS -- Routines for inserting and extracting bitfields into integers.
# BITPAK -- Pack an integer into a bitfield of an array. Set all nbits
# bits regardless of the value of the integer.
.text
.align 1
.globl _bitpak_
# bitpak (intval, array, offset, nbits)
.set INTVAL, 4
.set ARRAY, 8
.set OFFSET, 12 # one-indexed bit offset
.set NBITS, 16
_bitpak_:
.word 0x0
subl3 $1, *OFFSET(ap), r1
insv *INTVAL(ap), r1, *NBITS(ap), *ARRAY(ap)
ret
.data
# BITUPK -- Unpack a bitfield from an array and return as the function
# value, an integer. Do not sign extend.
.text
.align 1
.globl _bitupk_
# bitupk (array, offset, nbits)
.set ARRAY, 4
.set OFFSET, 8 # one-indexed bit offset
.set NBITS, 12
_bitupk_:
.word 0x0
subl3 $1, *OFFSET(ap), r1
extzv r1, *NBITS(ap), *ARRAY(ap), r0
ret
.data
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