Evan Cheng ffc0e73046 Change createAsmParser to take a MCSubtargetInfo instead of triple,
CPU, and feature string. Parsing some asm directives can change
subtarget state (e.g. .code 16) and it must be reflected in other
modules (e.g. MCCodeEmitter). That is, the MCSubtargetInfo instance
must be shared.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134795 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-09 05:47:46 +00:00
..

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add gcc builtins for alpha instructions


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custom expand byteswap into nifty 
extract/insert/mask byte/word/longword/quadword low/high
sequences

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see if any of the extract/insert/mask operations can be added

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match more interesting things for cmovlbc cmovlbs (move if low bit clear/set)

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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

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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 across bytes of bytewise abs(i8v8 a - i8v8 b))

cmpbytes bytewise cmpeq of i8v8 a and i8v8 b (not part of MVI extensions)

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