llvm/lib/Target/Alpha/README.txt
Andrew Lenharth a697b8d83d Readme
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@35533 91177308-0d34-0410-b5e6-96231b3b80d8
2007-03-31 15:05:44 +00:00

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***
add gcc builtins for alpha instructions
***
custom expand byteswap into nifty
extract/insert/mask byte/word/longword/quadword low/high
sequences
***
see if any of the extract/insert/mask operations can be added
***
match more interesting things for cmovlbc cmovlbs (move if low bit clear/set)
***
lower srem and urem
remq(i,j): i - (j * divq(i,j)) if j != 0
remqu(i,j): i - (j * divqu(i,j)) if j != 0
reml(i,j): i - (j * divl(i,j)) if j != 0
remlu(i,j): i - (j * divlu(i,j)) if j != 0
***
add crazy vector instructions (MVI):
(MIN|MAX)(U|S)(B8|W4) min and max, signed and unsigned, byte and word
PKWB, UNPKBW pack/unpack word to byte
PKLB UNPKBL pack/unpack long to byte
PERR pixel error (sum accross bytes of bytewise abs(i8v8 a - i8v8 b))
cmpbytes bytewise cmpeq of i8v8 a and i8v8 b (not part of MVI extentions)
this has some good examples for other operations that can be synthesised well
from these rather meager vector ops (such as saturating add).
http://www.alphalinux.org/docs/MVI-full.html