[llvm-dev] About TableGen RangeList
陳韋任 via llvm-dev
llvm-dev at lists.llvm.org
Sat Apr 15 19:52:21 PDT 2017
Okay, a little experiment shows the order matters.
$ cat bits_4_0.td
def basic_bits {
bits<10> zz;
let zz{4-0} = 0b11001;
}
$ llvm-tblgen bits_4_0.td
def basic_bits {
bits<10> zz = { ?, ?, ?, ?, ?, 1, 1, 0, 0, 1 };
string NAME = ?;
}
$ cat bits_0_4.td
def basic_bits {
bits<10> zz;
let zz{0-4} = 0b11001;
}
$ llvm-tblgen bits_4_0.td
def basic_bits {
bits<10> zz = { ?, ?, ?, ?, ?, 1, 0, 0, 1, 1 };
string NAME = ?;
}
2017-04-15 23:55 GMT+08:00 陳韋任 <chenwj.cs97g at g2.nctu.edu.tw>:
> Hi All,
>
> One thing I believe also bothers someone else. Say we have the following
> code snippet:
>
> bits<32> insnEncoding;
> let insnEncoding{15-12} = 0b0100;
>
> Can we write the let expression with range list like this, with the same
> meaning?
>
> let insnEncoding{12-15} = 0b0100;
>
> I take a look on TGParser::ParseRangePiece (lib/TableGen/TGParser.cpp),
> seems the
> answer is YES. Can anyone confirm this?
>
> Thanks.
>
> Regards,
> chenwj
>
> --
> Wei-Ren Chen (陳韋任)
> Homepage: https://people.cs.nctu.edu.tw/~chenwj
--
Wei-Ren Chen (陳韋任)
Homepage: https://people.cs.nctu.edu.tw/~chenwj
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