This was added in OpenACC PR #511 in the 3.4 branch. From an AST/Sema
perspective this is pretty trivial as the infrastructure for 'if'
already exists, however the atomic construct needed to be taught to take
clauses. This patch does that and adds some testing to do so.
This is the last item of the OpenACC 3.3 spec. It includes the
implicit-name version of 'routine', plus significant refactorings to
make the two work together. The implicit name version is represented as
an attribute on the function call. This patch also implements the
clauses for the implicit-name version, as well as the A.3.4 warning.
The 'bind' clause allows the renaming of a function during code
generation. There are a few rules about when this can/cannot happen,
and it takes either a string or identifier (previously mis-implemetned
as ID-expression) argument.
Note there are additional rules to this in the implicit-function routine
case, but that isn't implemented in this patch, as implicit-function
routine is not yet implemented either.
There is a slightly different list for routine on which clauses are
permitted after it (like the rest of the constructs), but this
implements and tests them to make sure we get them right.
'nohost' is only valid on routine, and states that the compiler
shouldn't compile this routine for the host. It has no arguments, so no
checking is required besides putting it in the AST.
These 4 clauses are mutually exclusive, AND require at least one of
them. Additionally, gang has some additional restrictions in that only
the 'dim' specifier is permitted. This patch implements all of this, and
ends up refactoring the handling of each of these clauses for
readabililty.
We previously allowed duplicates of auto/seq/independent on a 'loop'
construct. This is disallowed by the restriction (which says exactly one
of...), so this patch ensures they are disallowed.
The 'declare' construct is the first of two 'declaration' level
constructs, so it is legal in any place a declaration is, including as a
statement, which this accomplishes by wrapping it in a DeclStmt. All
clauses on this have a 'same scope' requirement, which this enforces as
declaration context instead, which makes it possible to implement these
as a template.
The 'link' and 'device_resident' clauses are also added, which have some
similar/small restrictions, but are otherwise pretty rote.
This patch implements all of the above.
The atomic construct is a particularly complicated one. The directive
itself is pretty simple, it has 5 options for the 'atomic-clause'.
However, the associated statement is fairly complicated.
'read' accepts:
v = x;
'write' accepts:
x = expr;
'update' (or no clause) accepts:
x++;
x--;
++x;
--x;
x binop= expr;
x = x binop expr;
x = expr binop x;
'capture' accepts either a compound statement, or:
v = x++;
v = x--;
v = ++x;
v = --x;
v = x binop= expr;
v = x = x binop expr;
v = x = expr binop x;
IF 'capture' has a compound statement, it accepts:
{v = x; x binop= expr; }
{x binop= expr; v = x; }
{v = x; x = x binop expr; }
{v = x; x = expr binop x; }
{x = x binop expr ;v = x; }
{x = expr binop x; v = x; }
{v = x; x = expr; }
{v = x; x++; }
{v = x; ++x; }
{x++; v = x; }
{++x; v = x; }
{v = x; x--; }
{v = x; --x; }
{x--; v = x; }
{--x; v = x; }
While these are all quite complicated, there is a significant amount
of similarity between the 'capture' and 'update' lists, so this patch
reuses a lot of the same functions.
This patch implements the entirety of 'atomic', creating a new Sema file
for the sema for it, as it is fairly sizable.
