[llvm-commits] [llvm] r73074 - in /llvm/trunk: docs/TableGenFundamentals.html test/TableGen/regmatch.td utils/TableGen/Record.cpp utils/TableGen/Record.h utils/TableGen/TGLexer.cpp utils/TableGen/TGLexer.h utils/TableGen/TGParser.cpp

[Török Edwin]

On 2009-06-08 20:00, David Greene wrote:
> Author: greened
> Date: Mon Jun  8 12:00:34 2009
> New Revision: 73074
>
> URL: http://llvm.org/viewvc/llvm-project?rev=73074&view=rev
> Log:
>
> Add a !regmatch operator to do pattern matching in TableGen.
>
>    }
> +  case REGMATCH: {
> +    StringInit *LHSs = dynamic_cast<StringInit*>(LHS);
> +    StringInit *RHSs = dynamic_cast<StringInit*>(RHS);
> +    if (LHSs && RHSs) {
> +      regex_t compiled;
> +      int err = regcomp (&compiled, LHSs->getValue().c_str(), REG_EXTENDED);
>   

Hi David,

If you are not using the nmatch/pmatch features of regexec(), you can
pass REG_NOSUB here.
In some situations it can result in a more efficient regular expression.

If REGMATCH is used often you could also compile the regular expression
just once (store it in a map?) and run it multiple times.

Best regards,
--Edwin