Re: [PATCH]: Add new bytecode op `switch' for implementing branch tables.

[Paul Eggert <eggert@cs.ucla.edu>]

On 02/10/2017 10:25 AM, Vibhav Pant wrote:
> Are there any other issues before I merge this into master?

For the C code, please use the usual style: space before paren in calls, 
GNU style indenting for curly braces, "/* " at start of comments, main 
operator like "||" at start of next line rather than at end of previous 
line.

One of the 'if's is overparenthesized, i.e., "if ((E))" where E is an 
ordinary expression and "if (E)" will do.

Prefer "if (BYTE_CODE_SAFE)" to "#ifdef BYTE_CODE_SAFE", as these days 
it's better to avoid the preprocessor when it's easy.

This comment:

                     /* Hash tables for switch are declared with :size 
set to the
                        exact number of cases, thus
                        HASH_TABLE_SIZE (h) == h->count.  */

is something that could be checked, no? Perhaps replace the comment with 
"if (BYTE_CODE_SAFE) eassert (HASH_TABLE_SIZE (h) == h->count);" and do 
the latter even with large hash tables?

If you change the loop from "for (i = 0; i < h->count; i++)" to "for (i 
= h->count; 0 <= --i; )", then you can merge the two copies of "op = 
XINT (HASH_VALUE (h, i)); goto ob_branch;" into one copy that is after 
the surrounding "if".