Re: [PING] RE: [Ping]FW: [PATCH] Cilk Plus merging to trunk (2 of n)

[Richard Biener <richard dot guenther at gmail dot com>]

On Tue, Dec 11, 2012 at 6:50 PM, Iyer, Balaji V <balaji.v.iyer@intel.com> wrote:
> Hello,
>         Did you get a chance to look at this patch? I submitted this ~1 month ago, so thought I would inquire its status.

Let me chime in from a release manager POV - I fear this needs to wait for
next stage1, we're way into stage3 to get such major features in.

Thanks,
Richard.

> Thanks,
>
> Balaji V. Iyer.
>
>> -----Original Message-----
>> From: Iyer, Balaji V
>> Sent: Monday, November 05, 2012 4:43 PM
>> To: Joseph Myers
>> Cc: gcc-patches@gcc.gnu.org
>> Subject: RE: [Ping]FW: [PATCH] Cilk Plus merging to trunk (2 of n)
>>
>> Hello Joseph,
>>       Here is the fixed patch with all your changes and the ChangeLog entries
>> below.
>>
>> gcc/ChangeLog
>> 2012-11-05  Balaji V. Iyer  <balaji.v.iyer@intel.com>
>>
>>         * Makefile.in (C_COMMON_OBJS): Added c-family/array-notation-
>> common.o.
>>         * doc/passes.texi (Cilk Plus Transformation): Documented array
>>         notation and overall transformations for Cilk Plus.
>>         * doc/invoke.texi (C Dialect Options): Documented -fcilkplus flag.
>>         * doc/generic.texi (Storage References): Documented
>> ARRAY_NOTATION_REF
>>         tree addition.
>>
>> gcc/c-family/ChangeLog
>> 2012-11-05  Balaji V. Iyer  <balaji.v.iyer@intel.com>
>>
>>         * c-common.h (build_array_notation_expr): New function declaration.
>>         (ARRAY_NOTATION_ARRAY): Added new #define.
>>         (ARRAY_NOTATION_CHECK): Likewise.
>>         (ARRAY_NOTATION_START): Likewise.
>>         (ARRAY_NOTATION_LENGTH): Likewise.
>>         (ARRAY_NOTATION_STRIDE): Likewise.
>>         (ARRAY_NOTATION_TYPE): Likewise.
>>         (enum array_notation_reduce_type): Added new enumerator.
>>         * c-common.def: Added new tree ARRAY_NOTATION_REF.
>>         * c-common.c (c_define_builtins): Added a call to initialize array
>>         notation builtin functions.
>>         (c_common_init_ts): Set ARRAY_NOTATION_REF as typed.
>>         * c-pretty-print.c (pp_c_postfix_expression): Added ARRAY_NOTATION_REF
>>         case.
>>         * c.opt (-fcilkplus): Define new command line switch.
>>         * array-notation-common.c: New file.
>>
>> gcc/c/ChangeLog
>> 2012-11-05  Balaji V. Iyer  <balaji.v.iyer@intel.com>
>>
>>         * c-typeck.c (build_array_ref): Added a check to see if array's index
>>         is greater than one.  If true, then emit an error.
>>         (build_function_call_vec): Exclude error reporting & checking for
>>         builtin array-notation functions.
>>         (convert_arguments): Likewise.
>>         (c_finish_return): Added a check for array notations as a return
>>         expression.  If true, then emit an error.
>>         (c_finish_loop): Added a check for array notations in a loop condition.
>>         If true then emit an error.
>>         (lvalue_p): Added a ARRAY_NOTATION_REF case.
>>         * Make-lang.in (C_AND_OBJC_OBJS): Added c-array-notation.o.
>>         * c-parser.c (c_parser_compound_statement): Check if array notation code
>>         is used in tree, if so, then transform them into appropriate C code.
>>         (c_parser_expr_no_commas): Check if array notation is used in LHS or
>>         RHS, if so, then build array notation expression instead of regular
>>         modify.
>>         (c_parser_postfix_expression_after_primary): Added a check for colon(s)
>>         after square braces, if so then handle it like an array notation.  Also,
>>         break up array notations in unary op if found.
>>         (c_parser_direct_declarator_inner): Added a check for array notation.
>>         (c_parser_compound_statement): Added a check for array notation in a
>>         stmt.  If one is present, then expand array notation expr.
>>         (c_parser_if_statement): Likewise.
>>         (c_parser_switch_statement): Added a check for array notations in a
>>         switch statement's condition.  If true, then output an error.
>>         (c_parser_while_statement): Same as switch statement, but for a while.
>>         (c_parser_do_statement): Same as switch statement, but for a do-while.
>>         (c_parser_for_statement): Same as switch statement, but for a for-loop.
>>         (c_parser_unary_expression): Check if array notation is used in a
>>         pre-increment or pre-decrement expression.  If true, then expand them.
>>         (c_parser_array_notation): New function.
>>         * c-array-notation.c: New file.
>>
>> gcc/testsuite/ChangeLog
>> 2012-11-05  Balaji V. Iyer  <balaji.v.iyer@intel.com>
>>
>>         * gcc.dg/cilk-plus/array_notation/execute/execute.exp: New script.
>>         * gcc.dg/cilk-plus/array_notation/compile/compile.exp: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/errors.exp: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/sec_implicit_ex.c: New test.
>>         * gcc.dg/cilk-plus/array_notation/execute/comma_exp.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/conditional.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/exec-once.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/if_test.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/n-ptr_test.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/gather_scatter.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/builtin_func_double2.c:
>>         Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/builtin_func_double.c:
>>         Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/builtin_fn_custom.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/builtin_fn_mutating.c:
>>         Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/array_test_ND.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/array_test2.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/execute/array_test1.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/compile/sec_implicit_ex.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/compile/gather_scatter.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/compile/builtin_func_double2.c:
>>         Likewise.
>>         * gcc.dg/cilk-plus/array_notation/compile/array_test_ND.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/compile/if_test.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/compile/builtin_func_double.c:
>>         Likewise.
>>         * gcc.dg/cilk-plus/array_notation/compile/array_test1.c: Likewise
>>         * gcc.dg/cilk-plus/array_notation/compile/array_test2.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/sec_implicit.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/sec_implicit2.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/rank_mismatch.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/parse_error.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/parse_error2.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/parse_error3.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/parse_error4.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/sec_reduce_max_min_ind.c:
>>         Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/decl-ptr-colon.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/fn_ptr.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/fn_triplet_values.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/gather-scatter.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/misc.c: Likewise.
>>         * gcc.dg/cilk-plus/array_notation/errors/vla.c: Likewise.
>>
>> Thanks,
>>
>> Balaji V. Iyer.
>>
>>
>> > -----Original Message-----
>> > From: Joseph Myers [mailto:joseph@codesourcery.com]
>> > Sent: Friday, October 19, 2012 5:38 PM
>> > To: Iyer, Balaji V
>> > Cc: Richard Guenther; gcc-patches@gcc.gnu.org
>> > Subject: RE: [Ping]FW: [PATCH] Cilk Plus merging to trunk (2 of n)
>> >
>> > On Thu, 4 Oct 2012, Iyer, Balaji V wrote:
>> >
>> > > >>>>Here is a link to the latest spec. This should clear several of
>> > > >>>>the questions you are seeking.
>> > > >>>>(http://software.intel.com/sites/default/files/m/4/e/7/3/1/40297
>> > > >>>>-
>> > > >>>>Intel_Cilk_plus_lang_spec_2.htm#array)
>> >
>> > This specification is much improved, especially as regards specifying
>> > the types of section expressions.  I'm not convinced that "the type of'
>> > the array being subscripted shall have a declared size" is properly
>> > defined in standard terms, but I can guess reasonable semantics - that
>> > if the array-to-pointer decay were considered not to occur in such a
>> > context, then the expressions for the array being subscripted shall
>> > have array type, not pointer type, and the array type shall not be one
>> > with unspecified size (array[]), although it may be a VLA.  For
>> > example, given "int a[10];", it would be valid to say a[:] or (a)[:]
>> > but not (+a)[:].  I don't, however, see any testcases at all in this
>> > patch for that particular requirements - not even for the completely clear-cut
>> cases, such as giving an error for "extern int a[]; a[:];" or "int *a; a[:];".
>> >
>> > Say expr1 through expr9 are expressions with side effects, and you have:
>> >
>> > expr1[expr2:expr3:expr4] = expr5[expr6:expr7:expr8] + expr9;
>> >
>> > The spec says "However, in such a statement, a sub-expression with
>> > rank zero is evaluated only once." - that is, each of the nine
>> > expressions is evaluated once.  I don't see any calls to save_expr to
>> > ensure these semantics, or any testcases that verify that they are adhered to.
>> >
>> > (Are multidimensional section expressions valid when what you have is
>> > pointers to pointers, e.g. "int ***p; p[0:10][0:10][0:10];"?  I don't
>> > see anything to rule them out, so I assume they are valid, but don't
>> > see testcases for them either.)
>> >
>> > Looking at the patch itself:
>> >
>> > In find_rank you have error ("Rank Mismatch!"); - this is not a
>> > properly formatted error message according to the GNU Coding standards
>> > (which typically would not have any uppercase).  I'd also suggest that
>> > when you find a rank, you store (through a location_t * pointer) the
>> > location of the first expression found with that rank, so if you then
>> > find a mismatching rank you can use error_at to point to that rank and
>> > then inform to point to the previous rank it didn't match.
>> >
>> > I'm not convinced that your logic, falling back to examining each
>> > operand for a generic expression, is correct to find the ranks of all
>> > kinds of expressions.  For example, there are rules:
>> >
>> > * "The rank of a simple subscript expression (postfix-expression [
>> > expression ]) is the sum of the ranks of its operand expressions. The
>> > rank of the subscript operand shall not be greater than one." - how do
>> > you ensure this rule?  Where do you test for errors if the subscript
>> > has too high a rank (both in the front-end code, and in the
>> > testsuite), and test (in the testsuite) for cases where the subscript has rank 1?
>> >
>> > * "The rank of a comma expression is the rank of its second operand."
>> > - I don't see anything special to handle that.  Are there testcases
>> > for rank of comma expressions?  Apart from testing rank, you may need
>> > to test how they are evaluated (that each part, with independent rank,
>> > gets fully evaluted in turn) - I don't see anything obvious in the code to handle
>> them appropriately.
>> >
>> > In general, I'd say you should have tests in the testsuite for each
>> > syntactic type of expression supported by GCC, both standard and GNU
>> > extensions, testing how it interacts with section expressions - both
>> > valid cases, and cases that are invalid because of rank mismatches.
>> > As another example, you don't have tests of conditional expressions.
>> >
>> > Where do you test (both in code, and testcases to verify errors) that
>> > "The rank of each expression in a section triplet shall be zero."?
>> > What about "The rank of the postfix expression identifying the
>> > function to call shall be zero."?  "A full expression shall have rank
>> > zero, unless it appears in an expression statement or as the
>> > controlling expression of an if statement."?  (This means, I suppose,
>> > that uses such as initializers or sizes in array declarators must be
>> > rejected.)  I'd advise going through each sentence in the relevant part of the
>> spec that says something is invalid and making sure you diagnose it and have a
>> test of this.
>> >
>> > Where in the patch you use int for the size of something (e.g. a list)
>> > on the host, please use size_t.
>> >
>> > In extract_array_notation_exprs you appear to be reallocating every
>> > time something is added to a list (with XRESIZEVEC).  It would
>> > probably be more efficient to use the vec.h infrastructure for an
>> > automatically resizing vector on which you push things.
>> >
>> > In c_parser_array_notation you appear to be converting indices to
>> > integer_type_node in some cases, not converting at all in other cases.
>> > But the spec says "The expressions in a triplet are converted to
>> > ptrdiff_t.", so you need to convert to target ptrdiff_t, not target int.
>> > And there's a requirement that "Each of the expressions in a section
>> > triplet shall have integer type.".  So you need to check that, and
>> > give an error if it doesn't have integer type, before converting - and
>> > of course add testcases for each of the possible positions for an
>> > expression having one that doesn't have integer type.
>> >
>> > In c-typeck.c you disable some errors and warnings for expressions
>> > containing array notations.  I don't know where the later point is at
>> > which you check for such errors - but in any case, you need testcases
>> > for these diagnostics on those cases to show that they aren't being lost.
>> >
>> > In invoke.texi you have:
>> >
>> > +@opindex flag_enable_cilkplus
>> >
>> > But @opindex is for the user-visible options, not for internal variables.
>> > That is,
>> >
>> > @opindex fcilkplus
>> >
>> > would be appropriate.
>> >
>> > In passes.texi you refer to "the Cilk runtime library (located in
>> > libcilkrts directory)".  But no such directory is added by this patch.
>> > Only add references to it in documentation with the patch that adds
>> > the directory.
>> >
>> > --
>> > Joseph S. Myers
>> > joseph@codesourcery.com