Intel i86W Manual page 126

FLOATING-POINT INSTRUCTIONS
6.6.2.4 OR WITH MERGE REGISTER
form.dd fsrc1, fdest
fdest
~
fsrc1 OR MERGE
MERGE
~
0
pform.dd fsrc1, fdest
fdest
~
last stage graphics result
last stage graphics result
~
fsrc1 OR MERGE
MERGE ~ 0
(OR with MERGE Register)
(Plpelined OR with MERGE Register)
For intensity interpolation, the
form
instruction fetches the partially completed pixels
from the MERGE register, sets any additional bits that may be needed in the pixels (e.g.
texture values), and loads the result into a floating-point register.
Fsrcl
(when a register)
and
fdest
are floating-point register pairs; the
fsrc2
field of the instruction should contain
zero.
For distance interpolation or for intensity interpolation that does not require further
modification of the value in the MERGE register, the
fsrcl
operand of
form
may be
fO,
thereby causing the instruction to simply load the MERGE register into a floating-point
register.
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