On 10/22/2015 08:00 AM, Jakub Jelinek wrote: > On Thu, Oct 22, 2015 at 07:47:01AM -0700, Cesar Philippidis wrote: >>> But it is unclear from the parsing what from these is allowed: >> >> int v, w; >> ... >> gang(26) // equivalent to gang(num:26) >> gang(v) // gang(num:v) >> vector(length: 16) // vector(length: 16) >> vector(length: v) // vector(length: v) >> vector(16) // vector(length: 16) >> vector(v) // vector(length: v) >> worker(num: 16) // worker(num: 16) >> worker(num: v) // worker(num: 16) >> worker(16) // worker(num: 16) >> worker(v) // worker(num: 16) >> gang(16, 24) // technically gang(num:16, num:24) is acceptable but it >> // should be an error >> gang(v, w) // likewise >> gang(static: 16, num: 5) // gang(static: 16, num: 5) >> gang(static: v, num: w) // gang(static: v, num: w) >> gang(num: 5, static: 4) // gang(num: 5, static: 4) >> gang(num: v, static: w) // gang(num: v, static: w) >> >> Also note that the static argument can accept '*'. >> >>> and if the length: or num: part is really optional, then >>> int length, num; >>> vector(length) >>> worker(num) >>> gang(num, static: 6) >>> gang(static: 5, num) >>> should be also accepted (or subset thereof?). >> >> Interesting question. The spec is unclear. It defines gang, worker and >> vector as follows in section 2.7 in the OpenACC 2.0a spec: >> >> gang [( gang-arg-list )] >> worker [( [num:] int-expr )] >> vector [( [length:] int-expr )] >> >> where gang-arg is one of: >> >> [num:] int-expr >> static: size-expr >> >> and gang-arg-list may have at most one num and one static argument, >> and where size-expr is one of: >> >> * >> int-expr >> >> So I've interpreted that as a requirement that length and num must be >> followed by an int-expr, whatever that is. > > My reading of the above is that > vector(length) > is equivalent to > vector(length: length) > and > worker(num) > is equivalent to > vector(num: num) > etc. Basically, neither length nor num aren't reserved identifiers, > so you can use them for variable names, and if > vector(v) is equivalent to vector(length: v), then > vector(length) should be equivalent to vector(length:length) > or > vector(length + 1) should be equivalent to vector(length: length+1) > static is a keyword that can't start an integral expression, so I guess > it is fine if you issue an expected : diagnostics after it.
You're correct. I overlooked that 'int length, num' declaration. > In any case, please add a testcase (both C and C++) which covers all these > allowed variants (ideally one testcase) and rejected variants (another > testcase with dg-error). > > This is still an easy case, as even the C FE has 2 tokens lookup. > E.g. for OpenMP map clause where > map (always, tofrom: x) > means one thing and > map (always, tofrom, y) > another one (map (tofrom: always, tofrom, y)) > I had to do quite ugly things to get around this. I'll add more test cases. Thanks, Cesar
