This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [GSoC] decision tree first steps


On Thu, Jun 19, 2014 at 7:53 PM, Prathamesh Kulkarni
<bilbotheelffriend@gmail.com> wrote:
> On Thu, Jun 19, 2014 at 4:12 PM, Prathamesh Kulkarni
> <bilbotheelffriend@gmail.com> wrote:
>> On Thu, Jun 19, 2014 at 2:37 PM, Prathamesh Kulkarni
>> <bilbotheelffriend@gmail.com> wrote:
>>> On Wed, Jun 18, 2014 at 4:27 PM, Richard Biener
>>> <richard.guenther@gmail.com> wrote:
>>>> On Wed, Jun 18, 2014 at 11:21 AM, Prathamesh Kulkarni
>>>> <bilbotheelffriend@gmail.com> wrote:
>>>>> On Tue, Jun 17, 2014 at 3:15 PM, Richard Biener
>>>>> <richard.guenther@gmail.com> wrote:
>>>>>>
>>>>>> On Tue, Jun 17, 2014 at 12:21 AM, Prathamesh Kulkarni
>>>>>> <bilbotheelffriend@gmail.com> wrote:
>>>>>> > On Mon, Jun 16, 2014 at 4:45 PM, Richard Biener
>>>>>> > <richard.guenther@gmail.com> wrote:
>>>>>> >>
>>>>>> >> > * Patterns requiring GENERIC support like cond_expr
>>>>>> >> > I am not sure about how to handle these patterns. I was thinking about
>>>>>> >> > handling them after we have
>>>>>> >> > GENERIC code generation in place.
>>>>>> >>
>>>>>> >> Yeah, though handling GENERIC for matching is as simple as
>>>>>> >> emitting the code check twice, the 2nd check off the an else
>>>>>> >> from the if (TREE_CODE (op) == SSA_NAME).  That is,
>>>>>> >> arrange for expr::gen_gimple_match_dt to emit
>>>>>> >>
>>>>>> >>    if (TREE_CODE (...) == SSA_NAME)
>>>>>> >>      {
>>>>>> >>         gimple def_stmt = SSA_NAME_DEF_STMT (...);
>>>>>> >>         if (is_gimple_assign (def_stmt) && gimple_assign_rhs_code
>>>>>> >> (def_stmt) == <code>)
>>>>>> >>           {
>>>>>> >>   ....
>>>>>> >>      }
>>>>>> >>    else (TREE_CODE (...) == <code>)
>>>>>> >>      {
>>>>>> >>   ....
>>>>>> >>      }
>>>>>> >>
>>>>>> >> which would require some refactoring in the generator.  As for refactoring
>>>>>> >> it I'd not hook the gen_gimple_match_dt off the AST operands but
>>>>>> >> inline it in the decision tree traversal routine - that also makes the
>>>>>> >> commoning above easier.
>>>>>> > Thanks, I shall get started on this.
>>>>>>
>>>>>> Good.  You also miss the special-casing of REALPART_EXPR,
>>>>>> IMAGPART_EXPR, VIEW_CONVERT_EXPR and BIT_FIELD_REF
>>>>>> operand extraction as you say below.
>>>>>>
>>>>>> >>
>>>>>> >> Btw, I checked what we generate for (bogus)
>>>>>> >>
>>>>>> >> (match_and_simplify
>>>>>> >>   (MINUS_EXPR (PLUS_EXPR@2 @0 @1) @2)
>>>>>> >>   @1)
>>>>>> >>
>>>>>> >> and the DT looks like
>>>>>> >>
>>>>>> >> root, 1
>>>>>> >> |--operand: MINUS_EXPR, 1
>>>>>> >> |----operand: true, 1
>>>>>> >> |------operand: PLUS_EXPR, 1
>>>>>> >> |--------operand: true, 1
>>>>>> >> |----------operand: true, 1
>>>>>> >> |------------operand: match(1), 1
>>>>>> >> |--------------simplify_0, 0
>>>>>> >>
>>>>>> >> though I expected
>>>>>> >>
>>>>>> >> root, 1
>>>>>> >> |--operand: MINUS_EXPR, 1
>>>>>> >> |----operand: PLUS_EXPR, 1
>>>>>> >> |------operand: true, 1
>>>>>> >> |--------operand: true, 1
>>>>>> >> |----------operand: match(1), 1
>>>>>> >> |------------simplify_0, 0
>>>>>> >>
>>>>>> >> that is, I wonder where the extra "true" comes from.
>>>>>> > Thanks, fixed it in the current patch.
>>>>>>
>>>>>> Thanks.
>>>>>>
>>>>>> >>
>>>>>> >>
>>>>>> >> For
>>>>>> >>
>>>>>> >> (match_and_simplify
>>>>>> >>   (MINUS_EXPR @2 (PLUS_EXPR@2 @0 @1))
>>>>>> >>   @1)
>>>>>> >>
>>>>>> >> I get
>>>>>> >>
>>>>>> >> root, 1
>>>>>> >> |--operand: MINUS_EXPR, 1
>>>>>> >> |----operand: true, 1
>>>>>> >> |------operand: match(1), 1
>>>>>> >> |--------operand: PLUS_EXPR, 1
>>>>>> >> |----------operand: true, 1
>>>>>> >> |------------operand: true, 1
>>>>>> >> |--------------simplify_0, 0
>>>>>> >>
>>>>>> >> which looks good to me.
>>>>>> >>
>>>>>> >> There is still a fallthru for all match failures but the DT should ensure
>>>>>> >> that once any of the checks is false we can terminate - that is,
>>>>>> >> we never have to backtrack.  Sth simple like
>>>>>> >>
>>>>>> >> --- genmatch.c.orig     2014-06-16 12:57:38.401890454 +0200
>>>>>> >> +++ genmatch.c  2014-06-16 12:58:03.451888730 +0200
>>>>>> >> @@ -816,6 +816,7 @@
>>>>>> >>    unsigned i;
>>>>>> >>    for (i = 0; i < kids.length (); ++i)
>>>>>> >>      kids[i]->gen_gimple (f);
>>>>>> >> +  fprintf (f, "return false;\n");
>>>>>> >>
>>>>>> >>
>>>>>> >>    for (i = 0; i < n_braces; ++i)
>>>>>> >>      fprintf (f, "}\n");
>>>>>> >>
>>>>>> >> So overall I think we are ok sofar and don't need major changes in
>>>>>> >> the algorithm.
>>>>>> >>
>>>>>> >> I'd say add the missing call support and we're good to go ripping out
>>>>>> >> the non-decision tree path.
>>>>>> >>
>>>>>> >> I'm happy to do some of the refactoring that I'd like to see myself
>>>>>> >> so you can concentrate on pattern implementing for phase 2.  But
>>>>>> >> feel free to do some of it yourself.
>>>>>> >>
>>>>>> >> > Small point: I was wondering if it's a good idea to slightly change
>>>>>> >> > the syntax of pattern to sth like:
>>>>>> >> > match-expression -> transform  ?
>>>>>> >> > eg:
>>>>>> >> > (minus (plus @0 @1) @1) -> @0
>>>>>> >> > Looks smaller -:)
>>>>>> >>
>>>>>> >> Well, I suppose we stay with what we have here.
>>>>>> > The attached patch, adds support for built-in functions, and fixes
>>>>>> > insertion bug in decision tree.
>>>>>> > The insertion in decision tree is carried out during preorder traversal
>>>>>> > of AST (insert_operand), so it avoids generating preorder traversal in
>>>>>> > vector (removed walk_operand_preorder and
>>>>>> > lower_capture). For now have put (parent, pos, preorder_level) in
>>>>>> > separate struct operand_info, and added instance
>>>>>> > of this struct to operand (struct operand_info opinfo). operand_info
>>>>>> > is computed during preorder traversal
>>>>>> > (insert_operand), so parsing routines are not concerned with it.
>>>>>> > Eventually we should probably move
>>>>>> > matching code on decision tree nodes. For convenience of tracking
>>>>>> > patterns, I have numbered them in match.pd.
>>>>>>
>>>>>> Ok.
>>>>>>
>>>>>> > * Testing
>>>>>> > Total patterns in match.pd - 58
>>>>>> > Total test cases: 4 (match-1.c), 32 (match-decision-tree.c), match-2.c
>>>>>> > is screwed.
>>>>>>
>>>>>> How is it screwed?  I see it all pass ...
>>>>> The regexes are not written correctly.
>>>>> Multiple patterns have same regex in scan-tree-dump, so even if a
>>>>> particular test-case fails in isolation,
>>>>> it shows PASS when placed with other tests that are known to PASS.
>>>>
>>>> Ah ... bummer.  Probably a good opportunity to split the testcase
>>>> into multiple files.
>>>>
>>>>>> > Out of 22 remaining patterns:
>>>>>> > Not supported yet (require GENERIC support or special handling): 31
>>>>>> > (convert), 33, 34, 35 (realpart/imagpart), 37 (cond)
>>>>>> > Not able to write test-cases: 2, 16, 31, 38
>>>>>>
>>>>>> Sth like
>>>>>>
>>>>>> char *foo (char *p)
>>>>>> {
>>>>>>   int i = 0;
>>>>>>   return p + i;
>>>>>> }
>>>>>>
>>>>>> for 2) and using -fdump-tree-ccp1-details and scanning the
>>>>>> ccp1 dump for "Match-and-simplified definition of _4 to p_3(D)"
>>>>>> (ok, that's a quite non-informative dump message and we should
>>>>>> improve it ... ok, changed now to "Match-and-simplified p_3(D) + _2 to p_3(D)")
>>>>>>
>>>>>> 16) is expected (it would be possible to write a testcase but I'm not sure
>>>>>> we want to retain that pattern).  31) has a testcases in gcc.dg/pr58742-[123].c
>>>>>> At some point (well, maybe now ...) we want to remove those patterns
>>>>>> we implemented in match.pd from the manual code in tree-ssa-forwprop.c
>>>>>> so we don't see "false" passing of testcases written for them.
>>>>>> For 38) I have no idea how to get a FMA_EXPR with integer types ... probably
>>>>>> the pattern (and the corresponding code in fold-const.c) is "dead".
>>>>>
>>>>> There's a serious flaw in the previous patch.
>>>>> For these two (match) expressions:
>>>>> (minus @0 @1)
>>>>> (minus negate @1)
>>>>>
>>>>> AST1:   minus - @0 - @1
>>>>> AST2:   minus - negate - @1
>>>>>
>>>>> the decision tree is:
>>>>>              minus
>>>>>              /       \
>>>>>           negate  true
>>>>>             |           |
>>>>>            true      true
>>>>>
>>>>> However, the way it's implemented, negate's parent (AST2's minus), is
>>>>> *not* present in the decision tree (because the minus of AST1 is
>>>>> present in decision tree, and both minus nodes compare equal). Because
>>>>> both minus nodes have same opinfo contents (pos, level), it "works". A
>>>>> change to opinfo contents, which is different for both minus nodes,
>>>>> would break it. This is rather ugly.
>>>>
>>>> Oops.
>>>>
>>>>> I guess we first need to decouple operand_info from AST.
>>>>>
>>>>> Approach 1:
>>>>> We have struct operand_info, which stores whatever information is
>>>>> required to generate code for that operand.
>>>>> Keep that in dt_operand, and add a "parent" node that points to the
>>>>> decision tree node that the AST parent is mapped to.
>>>>> We are not relying anymore on parent in AST, but on the decision tree
>>>>> node, the parent is mapped to,
>>>>> which is same for equal comparing AST nodes.
>>>>>
>>>>> struct dt_operand
>>>>> {
>>>>>   operand *op;
>>>>>   operand_info opinfo;
>>>>>   dt_operand *parent;
>>>>> };
>>>>>
>>>>> and pass opinfo to code-generators in AST.
>>>>>
>>>>> struct operand {
>>>>>   ...
>>>>>   virtual unsigned gen_gimple_match_dt (FILE *, const char *opname,
>>>>> const operand_info&);
>>>>> };
>>>>>
>>>>> Approach 2:
>>>>> Keep separate representation of decision tree from AST.
>>>>> This would require mirroring some AST classes (dt_predicate, dt_expr, etc.).
>>>>> But the code-gen for matching is off the decision tree, and only
>>>>> transform code-gen
>>>>> is off the AST.
>>>>>
>>>>> Sth like:
>>>>> struct dt_operand
>>>>> {
>>>>>   operand *op;
>>>>>   operand_info opinfo;
>>>>>   dt_operand *parent;
>>>>>
>>>>>   virtual void gen_gimple (FILE *)  = 0;  // generate matching code
>>>>> };
>>>>>
>>>>> struct dt_expr: public dt_operand
>>>>> {
>>>>>   virtual void gen_gimple (FILE *);
>>>>> };
>>>>>
>>>>> struct dt_pred: public dt_operand
>>>>> {
>>>>>   virtual void gen_gimple (FILE *);
>>>>> };
>>>>>
>>>>> struct dt_true: ...
>>>>> struct dt_match ...
>>>>
>>>> I like approach 2 more but I wonder if we really need to subclass
>>>> dt_operand.  I think that the actual code-gen is easier to follow
>>>> if we do sth like
>>>>
>>>> dt_operand::gen_gimple ()
>>>> {
>>>>   switch (op->op_type)
>>>>     {
>>>>     case OP_EXPR:
>>>> ...
>>>>
>>>> not sure why I thought that using virtual methods is a good design
>>>> for the matching part.
>>>>
>>>>> * GENERIC code-gen.
>>>>> Walk the expression node twice:
>>>>> (expr-code operand0 operand1)
>>>>>
>>>>> if (TREE_CODE (o<preorder level>) == SSA_NAME)
>>>>>   {
>>>>>     gimple def_stmt<preorder level> = SSA_NAME_DEF_STMT (o<preorder level>);
>>>>>     if (is_gimple_assign (def_stmt<level>) && gimple_assign_rhs_code
>>>>> (def_stmt<level>) == expr-code)
>>>>>       {
>>>>>            // generate code for children and get child with gimple_assign_rhs
>>>>>       }
>>>>>   }
>>>>> else if (TREE_CODE (o<preorder level>) == expr-code)
>>>>>   {
>>>>>           // generate code for children and get child with TREE_OPERAND
>>>>>   }
>>>>>
>>>>> However this duplicates the code of operands.
>>>>
>>>> Yeah, for very deep DTs this could badly explode exponentially ...
>>>>
>>>>> Maybe we can get children of expression when we generate code for
>>>>> expr-node and store it in a "temps" array
>>>>> and then assign element of temps array to o<operand-level> when we
>>>>> generate code for operand-node.
>>>>> This is because at expr-node we don't know the preorder level of the
>>>>> child, else,
>>>>> we would have done - o<level> = gimple_assign_rhs() or o<level> =
>>>>> TREE_OPERAND ()
>>>>>
>>>>> tree temps[level-max][3]; // 3 is max number of operands an expression can have
>>>>> Keeping it 2d array, to avoid value getting overwritten by an inner expression.
>>>>> level-max  = level of AST that is greater than level of all other
>>>>> AST's. (or maybe we can assign a value which shall be a sufficient
>>>>> upper-bound like 4 for captures).
>>>>>
>>>>> example:
>>>>> consider binary expression with two operands:
>>>>>
>>>>> if (TREE_CODE (o<expr-level>) == SSA_NAME)
>>>>>   {
>>>>>      gimple def_stmt<expr-level> = SSA_NAME_DEF_STMT (o<expr-level>);
>>>>>      if (is_gimple_assign (def_stmt<expr-level>) &&
>>>>> gimple_assign_rhs_code (def_stmt<expr-level>) == expr-code)
>>>>>         {
>>>>>            temps[expr-level][0] = gimple_assign_rhs1 (def_stmt<expr-level>);
>>>>>            temps[expr-level][1] = gimple_assign_rhs2 (def_stmt<expr-level>);
>>>>>         }
>>>>>   }
>>>>> else if (TREE_CODE o<level> == expr-code)
>>>>>   {
>>>>>      temps[expr-level][0] = TREE_OPERAND (o<expr-level>, 0);
>>>>>      temps[expr-level][1] = TREE_OPERAND (o<expr-level>, 1);
>>>>>   }
>>>>> else
>>>>>     goto L0;   // gimple/generic variant's don't match go for next
>>>>> "sibling" pattern
>>>>>
>>>>> if (do_valueize (temps[expr-level][0]))
>>>>>   if (do_valueize (temps[expr-level][1]))
>>>>>     {
>>>>>        tree o<operand-1 level> = temps[expr-level][0];  // instead of
>>>>> o<operand-1 level> = gimple_assign_rhs1 ();
>>>>>        // generate code for operand-1
>>>>>
>>>>>            tree o<operand-2 level> = temps[expr-level][1];
>>>>>            // generate code for operand-2
>>>>>
>>>>>                <simplify>
>>>>>                return true;
>>>>>     }
>>>>>
>>>>> L0:
>>>>> // next pattern
>>>>
>>>> Hmm.  Actually we know exactly when we want to match GENERIC
>>>> and when we want to match SSA GIMPLE.  We want to match
>>>> GENERIC when we want to match REALPART_EXPR, IMAGPART_EXPR,
>>>> VIEW_CONVERT_EXPR and BIT_FIELD_REF _or_ when the parent(!)
>>>> matched for COND_EXPR and we are looking at its first operand
>>>> (yeah, I know ...).
>>>>
>>>> So we can decide at code-gen time what code to emit.
>>> The attached patch separates decision tree from AST, (removes the
>>> "parent bug") and attempts to
>>> add support for special case patterns requiring GENERIC (however it
>>> fails one test in match-1.c, I am looking
>>> into that). Code-gen for matching is off the decision tree and
>>> code-gen for transform is off the AST.
>>>
>>> * Representation of decision tree
>>> dt_operand is used for representing AST operand / true / match in the
>>> decision tree,
>>> dt_operand::parent points to the decision tree node, the AST parent is
>>> mapped to, not the pre-order predecessor.
>>> dt_operand::pos gives the operand number (0th operand, 1st operand,
>>> etc. of parent etc.)
>>> I have also clubbed true and match in the same class, because true
>>> does not require additional fields,
>>> and match has only one additional field (unsigned m_level).
>>>
>>> For the following pairs of (bogus) patterns:
>>> (plus @0 (bit_not@2 @1))
>>> (plus @1 (bit_not@3 @0))
>>>
>>> It builds following decision tree:
>>> (type, address, level, n_kids)
>>>
>>> root (0x1513550), 0, 1
>>> |--PLUS_EXPR (0x1502370), 1, 1
>>> |----true (0x15023f0), 2, 1
>>> |------BIT_NOT_EXPR (0x1502470), 3, 1
>>> |--------true (0x15024f0), 4, 2
>>> |----------simplify_0 { 2, 4, 3, 4294967295,  }  (0x1512540), 5, 0
>>> |----------simplify_1 { 4, 2, 4294967295, 3,  }  (0x15125c0), 5, 0
>>>
>>> and for the following pairs of (bogus) patterns:
>>> (plus (minus@0 @1 @2) @3)
>>> (plus (minus @0 @1) @2)
>>>
>>> It builds following tree:
>>> root (0x10e2520), 0, 1
>>> |--PLUS_EXPR (0x10d1370), 1, 1
>>> |----MINUS_EXPR (0x10d13f0), 2, 1
>>> |------true (0x10d1470), 3, 1
>>> |--------true (0x10d14f0), 4, 1
>>> |----------true (0x10e1540), 5, 2
>>> |------------simplify_0 { 2, 3, 4, 5,  }  (0x10e15c0), 6, 0
>>> |------------simplify_1 { 3, 4, 5, 4294967295,  }  (0x10e1640), 6, 0
>>>
>>> Is that correct ?
>>>
>>> * Code-gen
>>> The code-gen is mostly same, with following changes:
>>>
>>> a) Generation of expressions:
>>> At expr-node, the children are immediately assigned in temporaries
>>> (t0, t1 ,...),
>>> and when we come at child node, the temporary is assigned to child
>>> node (o<level> = t<count>).
>>> Temporary names are stored in dt_operand::temps vector.
>>>
>>> b) Is the following condition correct  (considering for convert) ?:
>>>
>>> if (is_gimple_assign (def_stmt) &&
>>>     (gimple_assign_rhs_code (def_stmt) == <expr-code>
>>>     || CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))))
>>>  {
>>>      // generated code for operands
>>>  }
>> oops, that's only for CONVERT_EXPR and NOP_EXPR.
>> Fixed in the current patch
> This patch fixes some more mistakes of the previous patch, and removes
> .gen_gimple_match functions.
> It now passes all tests from match-1.c
> The test-case was failing because I didn't generate valueize code correctly.
> It should have been:
> if ((t<count> = do_valueize (valueize, t<count>)) != 0)
> and the code getting generated was:
> if (do_valueize (valueize, t<count>))
>
> This patch supports all the patterns in match.pd. What changes would I
> need to make to make it a commit-ready patch ?
Added line directives in this patch.
I am not sure where to output line directives for match operands
since, they are interleaved in the decision tree.
I put line directives of respecitve patterns,on top of
if (code == <expr-code>), for all patterns having root as <expr-code>

Thanks and Regards,
Prathamesh

>
> Thanks and Regards,
> Prathamesh
>
>>
>> Thanks and Regards,
>> Prathamesh
>>>
>>> Example:
>>> For the pattern:
>>> (match_and_simplify
>>>   (minus (plus @0 @1) @1)
>>>   @0)
>>>
>>> It generated following code: http://pastebin.com/5QdCiZNi
>>>
>>> c) REALPART_EXPR / IMAGPART_EXPR / VIEW_CONVERT_EXPR / BIT_FIELD_REF:
>>> For these patterns, we generate GENERIC instead of GIMPLE to obtain operands ?
>>>
>>> Example:
>>> for the pattern:
>>> (match_and_simplify
>>>   (complex (realpart @0) (imagpart @0))
>>>   @0)
>>>
>>> it generated following code: http://pastebin.com/qXjEavDu
>>>
>>> d) COND_EXPR
>>> We generate GENERIC for 1st operand of COND_EXPR and not for the other
>>> operands (2nd, 3rd).
>>> Is that correct ?
>>>
>>> for the pattern:
>>> (match_and_simplify
>>>   (cond (bit_not @0) @1 @2)
>>>   (cond @0 @2 @1))
>>>
>>> it generates following code: http://pastebin.com/vL1dcb2E
>>>
>>> * GENERIC code generation.
>>> So far we are generating code for match-and-simplify on gimple.
>>> How do we start with GENERIC code-gen ?
>>>
>>> a) generate in gimple-match.c (or keep a different generic-match.c) ?
>>> b) Interface to GENERIC match_and_simplify - I guess it would be same as
>>> fold_binary / fold_unary ?
>>> c) We already have matching code in place for GENERIC
>>> (dt_operand::gen_generic_expr),
>>> we shall need to add code for generating GENERIC transforms.
>>>
>>> Thanks and Regards,
>>> Prathamesh
>>>
>>>>
>>>> Richard.
>>>>
>>>>> Thanks and Regards,
>>>>> Prathamesh
>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>> Richard.
>>>>>>
>>>>>> > I will add test-cases for remaining patterns shortly.
>>>>>> >
>>>>>> > Thanks and Regards,
>>>>>> > Prathamesh
>>>>>> >>
>>>>>> >> Thanks,
>>>>>> >> Richard.
>>>>>> >>
>>>>>> >> > Thanks and Regards
>>>>>> >> > Prathamesh
>>>>>> >> >>
>>>>>> >> >> Richard.
>>>>>> >> >>
>>>>>> >> >>>and for the commutative variant:
>>>>>> >> >>>(plus (negate@0 @1) @0) S
>>>>>> >> >>>
>>>>>> >> >>>the decision tree would be the following: ?
>>>>>> >> >>>plus - negate - true - true - match (3) - simplify
>>>>>> >> >>>
>>>>>> >> >>>Thanks and Regards,
>>>>>> >> >>>Prathamesh
>>>>>> >> >>>>
>>>>>> >> >>>> Richard.
>>>>>> >> >>>>
>>>>>> >> >>>>>> Richard.
>>>>>> >> >>>>>>
>>>>>> >> >>>>>>>> There are also opportunities to optimize the generated code, but
>>>>>> >> >>>>>>>> basic correctness first I guess.
>>>>>> >> >>>>>>>>
>>>>>> >> >>>>>>>> I suppose we have to work a bit on the capture stuff.
>>>>>> >> >>>>>>>>
>>>>>> >> >>>>>>>> Btw, you can easily play with the code generator by doing inside
>>>>>> >> >>>>>>>> the gcc build directory
>>>>>> >> >>>>>>>>
>>>>>> >> >>>>>>>> obj/gcc> build/genmatch test.pd > test.c
>>>>>> >> >>>>>>>>
>>>>>> >> >>>>>>>> with a small test.pd. I used the following for the above
>>>>>> >> >>>examples:
>>>>>> >> >>>>>>>>
>>>>>> >> >>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>   (MINUS_EXPR (PLUS_EXPR @0 @1) @0)
>>>>>> >> >>>>>>>>   @1)
>>>>>> >> >>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>   (MINUS_EXPR (PLUS_EXPR @1 @0) @0)
>>>>>> >> >>>>>>>>   @1)
>>>>>> >> >>>>>>
>>>>>> >> >>>>>>>> Richard.
>>>>>> >> >>>>>>>>
>>>>>> >> >>>>>>>>>> I will change this to have capture per pattern
>>>>>> >> >>>>>>>>>> tree captures1[4] = {};  // for pattern-1
>>>>>> >> >>>>>>>>>> tree captures2[4] = {};
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> Hmm, is this the matching captures issue I mentioned?  Btw, I
>>>>>> >> >>>see
>>>>>> >> >>>>>>>>> you do
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> +void
>>>>>> >> >>>>>>>>> +walk_operand_preorder(vec<operand *>& operands, operand *op)
>>>>>> >> >>>>>>>>> +{
>>>>>> >> >>>>>>>>> +  if (op->type == operand::OP_CAPTURE || op->type ==
>>>>>> >> >>>>>>>>> operand::OP_PREDICATE || op->type == operand::OP_C_EXPR)
>>>>>> >> >>>>>>>>> +    {
>>>>>> >> >>>>>>>>> +      operands.safe_push (op);
>>>>>> >> >>>>>>>>> +      return;
>>>>>> >> >>>>>>>>> +    }
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> but that leaves captured expressions as a single operand?
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> (plus (minus@1 @2 @3) @2)
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> would have a decision tree
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>>  plus -> minus -> @2
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> correct?
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>>> d) Matching multiple patterns.
>>>>>> >> >>>>>>>>>> Code for patterns with same match, but different transforms is
>>>>>> >> >>>>>>>>>> generated as follows:
>>>>>> >> >>>>>>>>>> code for match operand.
>>>>>> >> >>>>>>>>>> if (if-expr of pattern-1)
>>>>>> >> >>>>>>>>>> {
>>>>>> >> >>>>>>>>>>   code for result of pattern-1
>>>>>> >> >>>>>>>>>>   return true;
>>>>>> >> >>>>>>>>>> }
>>>>>> >> >>>>>>>>>> if (if-expr of pattern-2)
>>>>>> >> >>>>>>>>>> {
>>>>>> >> >>>>>>>>>>   code for result of pattern-2
>>>>>> >> >>>>>>>>>>   return true;
>>>>>> >> >>>>>>>>>> }
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> good.
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>>> ...
>>>>>> >> >>>>>>>>>> Should we emit a warning for patterns that have same match
>>>>>> >> >>>operand but
>>>>>> >> >>>>>>>>>> no if-expr and no manual transform ?
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> for eg:
>>>>>> >> >>>>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>>>   (plus (minus @0 @1) @1)
>>>>>> >> >>>>>>>>>>   @0
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>>>   (plus (minus @0 @1) @1)
>>>>>> >> >>>>>>>>>>   @1  // just for illustration
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> Since the matching is ambiguous (same match, no if-expr, no
>>>>>> >> >>>manual
>>>>>> >> >>>>>>>>>> transform).
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> Yeah, I suppose we should.
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>>> we are left to choose between result of pattern-1 and result of
>>>>>> >> >>>>>>>>>> pattern-2.
>>>>>> >> >>>>>>>>>> We can emit warning and choose result of pattern-1 (first-match
>>>>>> >> >>>rule
>>>>>> >> >>>>>>>>>> as in flex).
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> e) Non-matching captures:
>>>>>> >> >>>>>>>>>> Haven't thought about this yet.
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> * Should we add "negative" predicates that match only if the
>>>>>> >> >>>predicate
>>>>>> >> >>>>>>>>>> fails ?
>>>>>> >> >>>>>>>>>> for eg:
>>>>>> >> >>>>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>>>   trunc_mod integer_zerop@0 !integer_zerop)
>>>>>> >> >>>>>>>>>>   @0)
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> well, there could simply be a integer_not_zerop predicate.
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>>> * Testing
>>>>>> >> >>>>>>>>>> Sorry to bring this up again, but I am still not clear what
>>>>>> >> >>>regex to
>>>>>> >> >>>>>>>>>> write in scan-tree-dump.
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> Suppose we have these two patterns in match.pd:
>>>>>> >> >>>>>>>>>> /* (x + y) - y -> x */
>>>>>> >> >>>>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>>>   (minus (plus @0 @1) @1)
>>>>>> >> >>>>>>>>>>   @0)
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> /* (x - y) + y -> x */
>>>>>> >> >>>>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>>>   (plus (minus @0 @1) @1)
>>>>>> >> >>>>>>>>>>   @0)
>>>>>> >> >>>>>>>>>> scan-tree-dump "gimple_match_and_simplified to \[^\n\r\]*=
>>>>>> >> >>>>>>>>>> x_\\d\+\\(D\\)"
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> I have following test-cases:
>>>>>> >> >>>>>>>>>> int f1(int x, int y)
>>>>>> >> >>>>>>>>>> {
>>>>>> >> >>>>>>>>>>   int t1 = x + y;
>>>>>> >> >>>>>>>>>>   return t1 - y;
>>>>>> >> >>>>>>>>>> }
>>>>>> >> >>>>>>>>>> scan-tree-dump "gimple_match_and_simplified to \[^\n\r\]*=
>>>>>> >> >>>>>>>>>> x_\\d\+\\(D\\)"
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> int f2(int x, int y)
>>>>>> >> >>>>>>>>>> {
>>>>>> >> >>>>>>>>>>   int t1 = x - y;
>>>>>> >> >>>>>>>>>>   return t1 + y;
>>>>>> >> >>>>>>>>>> }
>>>>>> >> >>>>>>>>>> scan-tree-dump "gimple_match_and_simplified to \[^\n\r\]*=
>>>>>> >> >>>>>>>>>> x_\\d\+\\(D\\)"
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> both the test-cases have same regex.
>>>>>> >> >>>>>>>>>> Tested in isolation f1 passes (first pattern if fired) and f2
>>>>>> >> >>>fails
>>>>>> >> >>>>>>>>>> (second pattern doesn't fire, it does after
>>>>>> >> >>>>>>>>>> adding it's commutative variant, but that's irrelevant for this
>>>>>> >> >>>case).
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> However when both test-cases are put in one file both the test
>>>>>> >> >>>cases
>>>>>> >> >>>>>>>>>> PASS.
>>>>>> >> >>>>>>>>>> I think that's because both of them have same regex:
>>>>>> >> >>>\[^\n\r\]*=
>>>>>> >> >>>>>>>>>> x_\\d\+\\(D\\)
>>>>>> >> >>>>>>>>>> so in f1 and f2's regex both match the dump for f1 function in
>>>>>> >> >>>>>>>>>> forwprop dump file:
>>>>>> >> >>>>>>>>>> "gimple_match_and_simplified to \[^\n\r\]*= x_\\d\+\\(D\\)
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> As a quick hack i rewrote f1 and f2 as:
>>>>>> >> >>>>>>>>>> int f1(int x, int y)
>>>>>> >> >>>>>>>>>> {
>>>>>> >> >>>>>>>>>>   int t1 = x + y;
>>>>>> >> >>>>>>>>>>   int f1_val = t1 - y;
>>>>>> >> >>>>>>>>>>   return f1_val;
>>>>>> >> >>>>>>>>>> }
>>>>>> >> >>>>>>>>>> scan-tree-dump "gimple_match_and_simplified to f1_val_\\d\+ =
>>>>>> >> >>>>>>>>>> x_\\d\+\\(D\\)"
>>>>>> >> >>>>>>>>>>
>>>>>> >> >>>>>>>>>> int f2(int x, int y)
>>>>>> >> >>>>>>>>>> {
>>>>>> >> >>>>>>>>>>   int t1 = x - y;
>>>>>> >> >>>>>>>>>>   int f2_val = t1 + y;
>>>>>> >> >>>>>>>>>>   return f2_val;
>>>>>> >> >>>>>>>>>> }
>>>>>> >> >>>>>>>>>> scan-tree-dump "gimple_match_and_simplified to f2_val_\\d\+ =
>>>>>> >> >>>>>>>>>> x_\\d\+\\(D\\)"
>>>>>> >> >>>>>>>>>> so both f1 and f2's scan-tree-dump have different regexes.
>>>>>> >> >>>>>>>>>> and f2's regex does not match dump of f1's function.
>>>>>> >> >>>>>>>>>> This matches all patterns in match-decision-tree.c however this
>>>>>> >> >>>is not
>>>>>> >> >>>>>>>>>> ideal,
>>>>>> >> >>>>>>>>>> since it does not check for matching dump across newlines.
>>>>>> >> >>>>>>>>>> Could you suggest a better way ?
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> There isn't a good better way (the others explicitely do _not_
>>>>>> >> >>>match
>>>>>> >> >>>>>>>>> against
>>>>>> >> >>>>>>>>> a newline - see the ^ in the \[\] group).  Well, apart from
>>>>>> >> >>>splitting
>>>>>> >> >>>>>>>>> the testcase
>>>>>> >> >>>>>>>>> into multiple files of course.
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>> Richard.
>>>>>> >> >>>>>>>>>
>>>>>> >> >>>>>>>>>> Thanks and Regards,
>>>>>> >> >>>>>>>>>> Prathamesh
>>>>>> >> >>>>>>>>>>>
>>>>>> >> >>>>>>>>>>> Thanks,
>>>>>> >> >>>>>>>>>>> Richard.
>>>>>> >> >>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>> Thanks and Regards,
>>>>>> >> >>>>>>>>>>>>> Prathamesh
>>>>>> >> >>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>> Richard.
>>>>>> >> >>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> * Code generation.
>>>>>> >> >>>>>>>>>>>>>>> Code shall be generated by walking the decision tree.
>>>>>> >> >>>>>>>>>>>>>>> The way it's constructed, there's no difference between
>>>>>> >> >>>code
>>>>>> >> >>>>>>>>>>>>>>> generation
>>>>>> >> >>>>>>>>>>>>>>> for "matching" and code generation for "transform". For
>>>>>> >> >>>>>>>>>>>>>>> non-simplificaton
>>>>>> >> >>>>>>>>>>>>>>> operands, "matching" code is generated, and for
>>>>>> >> >>>"simplification"
>>>>>> >> >>>>>>>>>>>>>>> operands,
>>>>>> >> >>>>>>>>>>>>>>> "transform" code is generated. The tree shall be walked
>>>>>> >> >>>twice,
>>>>>> >> >>>>>>>>>>>>>>> once to generate GIMPLE code and second time for GENERIC.
>>>>>> >> >>>>>>>>>>>>>>> For simplicity, I currently return false whenever there's
>>>>>> >> >>>a fail
>>>>>> >> >>>>>>>>>>>>>>> in match,
>>>>>> >> >>>>>>>>>>>>>>> instead of trying to match the next pattern.
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Code-gen for capture - same as capture::gen_gimple_match.
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Code-gen for predicate -  I haven't added support for
>>>>>> >> >>>predicate
>>>>>> >> >>>>>>>>>>>>>>> in
>>>>>> >> >>>>>>>>>>>>>>> decision tree yet, but I guess that would be the same as
>>>>>> >> >>>>>>>>>>>>>>> predicate::gen_gimple_match
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Code-gen for expr.
>>>>>> >> >>>>>>>>>>>>>>> There are two types of code-gen for expr.
>>>>>> >> >>>>>>>>>>>>>>> The patch generates following code:
>>>>>> >> >>>>>>>>>>>>>>> Type 1 - expr is child of root node.
>>>>>> >> >>>>>>>>>>>>>>> the only code that gets generated is (in
>>>>>> >> >>>>>>>>>>>>>>> decision_tree::gen_gimple):
>>>>>> >> >>>>>>>>>>>>>>> if (code == <expr code>)
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>> tree captures[4] = {}
>>>>>> >> >>>>>>>>>>>>>>> <generated code for children>
>>>>>> >> >>>>>>>>>>>>>>> }
>>>>>> >> >>>>>>>>>>>>>>> This is similar to generating matching code in
>>>>>> >> >>>>>>>>>>>>>>> write_nary_simplifiers.
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Type 2 - expr_1 is a child of another expr_0 node.
>>>>>> >> >>>>>>>>>>>>>>> The code gets generated as follows (dt_expr::gen_gimple):
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>> gimple def_stmt = SSA_NAME_DEF_STMT (op);
>>>>>> >> >>>>>>>>>>>>>>> if (is_gimple_assign (def_stmt)
>>>>>> >> >>>>>>>>>>>>>>>     && gimple_assign_rhs_code (def_stmt) == <expr_1-code>)
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>> tree op = gimple_assign_rhs1 (def_stmt);
>>>>>> >> >>>>>>>>>>>>>>> if (valueize && TREE_CODE (op) == SSA_NAME)
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>>   op = valueize (op);
>>>>>> >> >>>>>>>>>>>>>>>   if (!op) return false;
>>>>>> >> >>>>>>>>>>>>>>> }
>>>>>> >> >>>>>>>>>>>>>>> <code-gen for children of expr_1 node>
>>>>>> >> >>>>>>>>>>>>>>> }
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Example:
>>>>>> >> >>>>>>>>>>>>>>> (negate (negate @0))
>>>>>> >> >>>>>>>>>>>>>>> S1
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> (negate (bit_not @0))
>>>>>> >> >>>>>>>>>>>>>>> S2
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> decision tree:
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>>                 dummy/root
>>>>>> >> >>>>>>>>>>>>>>>                         |
>>>>>> >> >>>>>>>>>>>>>>>            NEGATE_EXPR
>>>>>> >> >>>>>>>>>>>>>>>              /                  \
>>>>>> >> >>>>>>>>>>>>>>>      BIT_NOT           NEGATE_EXPR
>>>>>> >> >>>>>>>>>>>>>>>            |                         |
>>>>>> >> >>>>>>>>>>>>>>>          @0                     @0
>>>>>> >> >>>>>>>>>>>>>>>            |                         |
>>>>>> >> >>>>>>>>>>>>>>>          S1                      S2
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> // code-gen for NEGATE_EXPR (child of root):
>>>>>> >> >>>>>>>>>>>>>>> if (code == NEGATE_EXPR)
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>> tree captures[4] = {};
>>>>>> >> >>>>>>>>>>>>>>> // code gen for BIT_NOT_EXPR
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>> gimple def_stmt = SSA_NAME_DEF_STMT (op0);
>>>>>> >> >>>>>>>>>>>>>>> if (is_gimple_assign (def_stmt)
>>>>>> >> >>>>>>>>>>>>>>>     && gimple_assign_rhs_code (def_stmt) == BIT_NOT_EXPR)
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>> tree op = gimple_assign_rhs1 (def_stmt);
>>>>>> >> >>>>>>>>>>>>>>> if (valueize && TREE_CODE (op) == SSA_NAME)
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>>   op = valueize (op);
>>>>>> >> >>>>>>>>>>>>>>>   if (!op) return false;
>>>>>> >> >>>>>>>>>>>>>>> }
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> // code-gen for @0, child of BIT_NOT_EXPR
>>>>>> >> >>>>>>>>>>>>>>> if (!captures[0])
>>>>>> >> >>>>>>>>>>>>>>>   captures[0] = op;
>>>>>> >> >>>>>>>>>>>>>>> else if (captures[0] != op)
>>>>>> >> >>>>>>>>>>>>>>>   return false;
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> // code-gen for S1, child of @0
>>>>>> >> >>>>>>>>>>>>>>> < same as code generated by .gen_gimple_transform >
>>>>>> >> >>>>>>>>>>>>>>> return true;
>>>>>> >> >>>>>>>>>>>>>>> }
>>>>>> >> >>>>>>>>>>>>>>> // code gen for inner NEGATE_EXPR
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>> gimple def_stmt = SSA_NAME_DEF_STMT (op0);
>>>>>> >> >>>>>>>>>>>>>>> if (is_gimple_assign (def_stmt)
>>>>>> >> >>>>>>>>>>>>>>>     && gimple_assign_rhs_code (def_stmt) == NEGATE_EXPR)
>>>>>> >> >>>>>>>>>>>>>>> <rest similar to the BIT_NOT case>
>>>>>> >> >>>>>>>>>>>>>>> }
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> The following gets duplicated with the patch:
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>> gimple_def_stmt = SSA_NAME_DEF_STMT (op0);
>>>>>> >> >>>>>>>>>>>>>>> if (TREE_CODE (op0) != SSA_NAME)
>>>>>> >> >>>>>>>>>>>>>>>   return false;
>>>>>> >> >>>>>>>>>>>>>>> if (is_gimple_assign (def_stmt)
>>>>>> >> >>>>>>>>>>>>>>>     && gimple_assign_rhs_code (def_stmt) == <expr-code>)
>>>>>> >> >>>>>>>>>>>>>>> ...
>>>>>> >> >>>>>>>>>>>>>>> }
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Improving code-gen for expr:
>>>>>> >> >>>>>>>>>>>>>>> "gimple def_stmt = ..." and "if (TREE_CODE (op0)" get
>>>>>> >> >>>duplicated,
>>>>>> >> >>>>>>>>>>>>>>> while they could be factored out, similar to this:
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>> gimple def_stmt = SSA_NAME_DEF_STMT (op0);
>>>>>> >> >>>>>>>>>>>>>>> if (TREE_CODE (op0) != SSA_NAME)
>>>>>> >> >>>>>>>>>>>>>>>   return false;
>>>>>> >> >>>>>>>>>>>>>>> if (!is_gimple_assign (def_stmt))
>>>>>> >> >>>>>>>>>>>>>>>   return false;
>>>>>> >> >>>>>>>>>>>>>>> if (gimple_assign_rhs_code (def_stmt) == BIT_NOT_EXPR)
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>>   // code-gen for BIT_NOT_EXPR subtree
>>>>>> >> >>>>>>>>>>>>>>> }
>>>>>> >> >>>>>>>>>>>>>>> else if (gimple_assign_rhs_code (def_stmt) == NEGATE_EXPR)
>>>>>> >> >>>>>>>>>>>>>>> {
>>>>>> >> >>>>>>>>>>>>>>>   // code-gen for NEGATE_EXPR subtree
>>>>>> >> >>>>>>>>>>>>>>> }
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> For factoring "gimple def_stmt ..." and "if (TREE_CODE
>>>>>> >> >>>(op0) !=
>>>>>> >> >>>>>>>>>>>>>>> SSA_NAME"
>>>>>> >> >>>>>>>>>>>>>>> we could have that generated at the parent of expr's node
>>>>>> >> >>>rather
>>>>>> >> >>>>>>>>>>>>>>> than
>>>>>> >> >>>>>>>>>>>>>>> at expr. However that would be incorrect for cases where
>>>>>> >> >>>not all
>>>>>> >> >>>>>>>>>>>>>>> children
>>>>>> >> >>>>>>>>>>>>>>> of a node are expressions:
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Example:
>>>>>> >> >>>>>>>>>>>>>>> // patterns only for illustration
>>>>>> >> >>>>>>>>>>>>>>> (negate (bit_not @0))
>>>>>> >> >>>>>>>>>>>>>>> (negate @0)
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>>                    root
>>>>>> >> >>>>>>>>>>>>>>>                      |
>>>>>> >> >>>>>>>>>>>>>>>                   negate
>>>>>> >> >>>>>>>>>>>>>>>                     /       \
>>>>>> >> >>>>>>>>>>>>>>>                 bit_not   @0
>>>>>> >> >>>>>>>>>>>>>>>                     |
>>>>>> >> >>>>>>>>>>>>>>>                   @0
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> we cannot have the above code generated at negate,
>>>>>> >> >>>>>>>>>>>>>>> since it's not applicable negate's 2nd child (@0).
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> This can be done by grouping together children that are
>>>>>> >> >>>>>>>>>>>>>>> expressions.
>>>>>> >> >>>>>>>>>>>>>>> However the patch does not do that.
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> * Code-gen for simplification operand
>>>>>> >> >>>>>>>>>>>>>>> This involves code-gen for ifexpr and result of pattern.
>>>>>> >> >>>>>>>>>>>>>>> Calls gen_gimple_transform of ifexpr and result
>>>>>> >> >>>>>>>>>>>>>>> (dt_simplify::gen_gimple)
>>>>>> >> >>>>>>>>>>>>>>> So this is really code-gen off AST
>>>>>> >> >>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>> Right (modulo replacing captures with their replacements).
>>>>>> >> >>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> * Matching multiple patterns
>>>>>> >> >>>>>>>>>>>>>>> A pattern has following parts: match, ifexpr and result.
>>>>>> >> >>>>>>>>>>>>>>> If pattern fails in match operand, I guess we can safely
>>>>>> >> >>>return
>>>>>> >> >>>>>>>>>>>>>>> false ?
>>>>>> >> >>>>>>>>>>>>>>> We "club" together patterns that have same match operand,
>>>>>> >> >>>>>>>>>>>>>>> and use goto, if one of them fails in their
>>>>>> >> >>>(ifexpr/result) and
>>>>>> >> >>>>>>>>>>>>>>> then goto the
>>>>>> >> >>>>>>>>>>>>>>> (ifexpr/result) of the next operand.
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Example:
>>>>>> >> >>>>>>>>>>>>>>> /* x & 0 -> 0 */
>>>>>> >> >>>>>>>>>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>>>>>>>>   (bit_and @0 @1)
>>>>>> >> >>>>>>>>>>>>>>>   if (INTEGRAL_TYPE_P (TREE_TYPE (@0)) && (@1 ==
>>>>>> >> >>>>>>>>>>>>>>> integer_zero_node))
>>>>>> >> >>>>>>>>>>>>>>>   { integer_zero_node; })
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> /* x & -1 -> x */
>>>>>> >> >>>>>>>>>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>>>>>>>>   (bit_and @0 @1)
>>>>>> >> >>>>>>>>>>>>>>>   if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
>>>>>> >> >>>>>>>>>>>>>>>      && (@1 == integer_minus_one_node)
>>>>>> >> >>>>>>>>>>>>>>>   @0)
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> For both patterns match is same.
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Decision Tree:
>>>>>> >> >>>>>>>>>>>>>>>                 bit_and
>>>>>> >> >>>>>>>>>>>>>>>                 /        \
>>>>>> >> >>>>>>>>>>>>>>>              @0      @1
>>>>>> >> >>>>>>>>>>>>>>>                            |
>>>>>> >> >>>>>>>>>>>>>>>                         S1,  S2
>>>>>> >> >>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>> I think it's worth adding a diagnostic to genmach whenever
>>>>>> >> >>>exactly
>>>>>> >> >>>>>>>>>>>>>> same matches appear.  But I'd say generally we'd support
>>>>>> >> >>>this
>>>>>> >> >>>>>>>>>>>>>> by testing the ifexpr of the next pattern.
>>>>>> >> >>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> S1 represents <ifexpr, result> of pattern-1, and S2
>>>>>> >> >>>represents
>>>>>> >> >>>>>>>>>>>>>>> <ifexpr, result>
>>>>>> >> >>>>>>>>>>>>>>> of pattern-2 respectively.
>>>>>> >> >>>>>>>>>>>>>>> S1, S2 would be stored as children of @1 (the last operand
>>>>>> >> >>>of
>>>>>> >> >>>>>>>>>>>>>>> n-ary operator),
>>>>>> >> >>>>>>>>>>>>>>> in dt_operand::kids vector.
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> The code would be generated as:
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> matching code.
>>>>>> >> >>>>>>>>>>>>>>> if (! pattern-1 ifexpr condition)
>>>>>> >> >>>>>>>>>>>>>>>   goto simplify2;  // next pattern with the same "match"
>>>>>> >> >>>operand.
>>>>>> >> >>>>>>>>>>>>>>> transform code for pattern 1
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> simplify2:
>>>>>> >> >>>>>>>>>>>>>>> if (! pattern-2 ifexpr condition)
>>>>>> >> >>>>>>>>>>>>>>>   return false;  // last pattern
>>>>>> >> >>>>>>>>>>>>>>> transform code for pattern 2.
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> If matching itself fails, that is neither of the decisions
>>>>>> >> >>>get
>>>>>> >> >>>>>>>>>>>>>>> matched,
>>>>>> >> >>>>>>>>>>>>>>> I believe we can then return false as it cannot match any
>>>>>> >> >>>other
>>>>>> >> >>>>>>>>>>>>>>> pattern ?
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> * patterns needing hacks like cond_expr or GENERIC support
>>>>>> >> >>>>>>>>>>>>>>> I haven't given thought to this yet. I suppose we can look
>>>>>> >> >>>to
>>>>>> >> >>>>>>>>>>>>>>> handle
>>>>>> >> >>>>>>>>>>>>>>> these after adding support for GENERIC. Instead of
>>>>>> >> >>>generating
>>>>>> >> >>>>>>>>>>>>>>> GENERIC
>>>>>> >> >>>>>>>>>>>>>>> matching in
>>>>>> >> >>>>>>>>>>>>>>> gimple_match_and_simplify, could we then call
>>>>>> >> >>>>>>>>>>>>>>> generic_match_and_simplify from
>>>>>> >> >>>>>>>>>>>>>>> within gimple_match_and_simplify ?
>>>>>> >> >>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>> Yes (that's what's currently done btw).
>>>>>> >> >>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> * Tests
>>>>>> >> >>>>>>>>>>>>>>> The patch transformed the following patterns:
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>>>>>>>>   (negate (bit_not @0))
>>>>>> >> >>>>>>>>>>>>>>>   if (INTEGRAL_TYPE_P (TREE_TYPE (@0)))
>>>>>> >> >>>>>>>>>>>>>>>   (plus @0 { build_int_cst (TREE_TYPE (@0)), 1); }))
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> (match_and_simplify
>>>>>> >> >>>>>>>>>>>>>>>   (negate (negate @0))
>>>>>> >> >>>>>>>>>>>>>>>   @0)
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> I have attached test-case I tried it with (negate.c)
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> * Conclusion
>>>>>> >> >>>>>>>>>>>>>>> Does it sound reasonable ? I am going to be re-writing the
>>>>>> >> >>>>>>>>>>>>>>> decision tree from scratch, but is the basic idea fine ?
>>>>>> >> >>>Or should
>>>>>> >> >>>>>>>>>>>>>>> we
>>>>>> >> >>>>>>>>>>>>>>> take a different approach ?
>>>>>> >> >>>>>>>>>>>>>>>
>>>>>> >> >>>>>>>>>>>>>>> Thanks and Regards,
>>>>>> >> >>>>>>>>>>>>>>> Prathamesh
>>>>>> >> >>>>>>
>>>>>> >> >>
>>>>>> >> >>
Index: gcc/genmatch.c
===================================================================
--- gcc/genmatch.c	(revision 211732)
+++ gcc/genmatch.c	(working copy)
@@ -29,7 +29,8 @@ along with GCC; see the file COPYING3.
 #include "hashtab.h"
 #include "hash-table.h"
 #include "vec.h"
-
+#include <stdlib.h>
+#include <limits.h>
 
 /* libccp helpers.  */
 
@@ -205,7 +206,6 @@ struct operand {
   enum op_type { OP_PREDICATE, OP_EXPR, OP_CAPTURE, OP_C_EXPR };
   operand (enum op_type type_) : type (type_) {}
   enum op_type type;
-  virtual void gen_gimple_match (FILE *f, const char *, const char * = NULL) = 0;
   virtual void gen_gimple_transform (FILE *f, const char *, const char *) = 0;
 };
 
@@ -213,7 +213,6 @@ struct predicate : public operand
 {
   predicate (const char *ident_) : operand (OP_PREDICATE), ident (ident_) {}
   const char *ident;
-  virtual void gen_gimple_match (FILE *f, const char *, const char *);
   virtual void gen_gimple_transform (FILE *, const char *, const char *) { gcc_unreachable (); }
 };
 
@@ -230,7 +229,6 @@ struct expr : public operand
   void append_op (operand *op) { ops.safe_push (op); }
   e_operation *operation;
   vec<operand *> ops;
-  virtual void gen_gimple_match (FILE *f, const char *, const char *);
   virtual void gen_gimple_transform (FILE *f, const char *, const char *);
 };
 
@@ -243,7 +241,6 @@ struct c_expr : public operand
   vec<cpp_token> code;
   unsigned nr_stmts;
   char *fname;
-  virtual void gen_gimple_match (FILE *, const char *, const char *) { gcc_unreachable (); }
   virtual void gen_gimple_transform (FILE *f, const char *, const char *);
 };
 
@@ -253,7 +250,6 @@ struct capture : public operand
       : operand (OP_CAPTURE), where (where_), what (what_) {}
   const char *where;
   operand *what;
-  virtual void gen_gimple_match (FILE *f, const char *, const char *);
   virtual void gen_gimple_transform (FILE *f, const char *, const char *);
 };
 
@@ -322,145 +318,6 @@ gen_gimple_match_fail (FILE *f, const ch
 }
 
 void
-predicate::gen_gimple_match (FILE *f, const char *op, const char *label)
-{
-  fprintf (f, "if (!%s (%s)) ", ident, op);
-  gen_gimple_match_fail (f, label);
-}
-
-void
-expr::gen_gimple_match (FILE *f, const char *name, const char *label)
-{
-  if (operation->op->kind == id_base::CODE)
-    {
-      operator_id *op = static_cast <operator_id *> (operation->op);
-      /* The GIMPLE variant.  */
-      fprintf (f, "if (TREE_CODE (%s) == SSA_NAME)\n", name);
-      fprintf (f, "  {\n");
-      fprintf (f, "gimple def_stmt = SSA_NAME_DEF_STMT (%s);\n", name);
-      fprintf (f, "if (!is_gimple_assign (def_stmt)\n");
-      if (op->code == NOP_EXPR
-	  || op->code == CONVERT_EXPR)
-	fprintf (f, "    || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))) ");
-      else
-	fprintf (f, "    || gimple_assign_rhs_code (def_stmt) != %s) ",  op->id);
-      gen_gimple_match_fail (f, label);
-      if (op->code == REALPART_EXPR
-	  || op->code == IMAGPART_EXPR
-	  || op->code == VIEW_CONVERT_EXPR
-	  || op->code == BIT_FIELD_REF)
-	{
-	  fprintf (f, "    tree rhs = gimple_assign_rhs1 (def_stmt);\n");
-	  for (unsigned i = 0; i < ops.length (); ++i)
-	    {
-	      fprintf (f, "   {\n");
-	      fprintf (f, "     tree op = TREE_OPERAND (rhs, %d);\n", i);
-	      fprintf (f, "     if (valueize && TREE_CODE (op) == SSA_NAME)\n");
-	      fprintf (f, "       {\n");
-	      fprintf (f, "         op = valueize (op);\n");
-	      fprintf (f, "         if (!op) ");
-	      gen_gimple_match_fail (f, label);
-	      fprintf (f, "       }\n");
-	      ops[i]->gen_gimple_match (f, "op", label);
-	      fprintf (f, "   }\n");
-	    }
-	}
-      else
-	{
-	  for (unsigned i = 0; i < ops.length (); ++i)
-	    {
-	      fprintf (f, "   {\n");
-	      fprintf (f, "     tree op = gimple_assign_rhs%d (def_stmt);\n", i + 1);
-	      fprintf (f, "     if (valueize && TREE_CODE (op) == SSA_NAME)\n");
-	      fprintf (f, "       {\n");
-	      fprintf (f, "         op = valueize (op);\n");
-	      fprintf (f, "         if (!op) ");
-	      gen_gimple_match_fail (f, label);
-	      fprintf (f, "       }\n");
-	      ops[i]->gen_gimple_match (f, "op", label);
-	      fprintf (f, "   }\n");
-	    }
-	}
-      fprintf (f, "  }\n");
-      /* The GENERIC variant.  */
-      fprintf (f, "else if (TREE_CODE (%s) == %s)\n", name, op->id);
-      fprintf (f, "  {\n");
-      for (unsigned i = 0; i < ops.length (); ++i)
-	{
-	  fprintf (f, "   {\n");
-	  fprintf (f, "     tree op_ = %s;\n", name);
-	  fprintf (f, "     tree op = TREE_OPERAND (op_, %d);\n", i);
-	  fprintf (f, "     if (valueize && TREE_CODE (op) == SSA_NAME)\n");
-	  fprintf (f, "       {\n");
-	  fprintf (f, "         op = valueize (op);\n");
-	  fprintf (f, "         if (!op) ");
-	  gen_gimple_match_fail (f, label);
-	  fprintf (f, "       }\n");
-	  ops[i]->gen_gimple_match (f, "op", label);
-	  fprintf (f, "   }\n");
-	}
-      fprintf (f, "  }\n");
-      fprintf (f, "else ");
-      gen_gimple_match_fail (f, label);
-    }
-  else if (operation->op->kind == id_base::FN)
-    {
-      fn_id *op = static_cast <fn_id *> (operation->op);
-      /* The GIMPLE variant.  */
-      fprintf (f, "if (TREE_CODE (%s) == SSA_NAME)\n", name);
-      fprintf (f, "  {\n");
-      fprintf (f, "gimple def_stmt = SSA_NAME_DEF_STMT (%s);\n", name);
-      fprintf (f, "if (!gimple_call_builtin_p (def_stmt, %s)) ", op->id);
-      gen_gimple_match_fail (f, label);
-      for (unsigned i = 0; i < ops.length (); ++i)
-	{
-	  fprintf (f, "   {\n");
-	  fprintf (f, "     tree op = gimple_call_arg (def_stmt, %d);\n", i);
-	  fprintf (f, "     if (valueize && TREE_CODE (op) == SSA_NAME)\n");
-	  fprintf (f, "       {\n");
-	  fprintf (f, "         op = valueize (op);\n");
-	  fprintf (f, "         if (!op) ");
-	  gen_gimple_match_fail (f, label);
-	  fprintf (f, "       }\n");
-	  ops[i]->gen_gimple_match (f, "op", label);
-	  fprintf (f, "   }\n");
-	}
-      fprintf (f, "  }\n");
-      /* GENERIC handling for calls.  */
-      fprintf (f, "else if (TREE_CODE (%s) == CALL_EXPR\n"
-	       "    && TREE_CODE (CALL_EXPR_FN (%s)) == ADDR_EXPR\n"
-	       "    && TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (%s), 0)) == FUNCTION_DECL\n"
-	       "    && DECL_BUILT_IN_CLASS (TREE_OPERAND (CALL_EXPR_FN (%s), 0)) == BUILT_IN_NORMAL\n"
-	       "    && DECL_FUNCTION_CODE (TREE_OPERAND (CALL_EXPR_FN (%s), 0)) == %s)\n",
-	       name, name, name, name, name, op->id);
-      fprintf (f, "  {\n");
-      for (unsigned i = 0; i < ops.length (); ++i)
-	{
-	  fprintf (f, "   {\n");
-	  fprintf (f, "     tree op = CALL_EXPR_ARG (%s, %d);\n", name, i);
-	  fprintf (f, "     if (valueize && TREE_CODE (op) == SSA_NAME)\n");
-	  fprintf (f, "       {\n");
-	  fprintf (f, "         op = valueize (op);\n");
-	  fprintf (f, "         if (!op) ");
-	  gen_gimple_match_fail (f, label);
-	  fprintf (f, "       }\n");
-	  ops[i]->gen_gimple_match (f, "op", label);
-	  fprintf (f, "   }\n");
-	}
-      fprintf (f, "  }\n");
-      fprintf (f, "else ");
-      gen_gimple_match_fail (f, label);
-    }
-  /* ???  Specifically COND_EXPR could also match on CFG diamonds.
-     (cond@3 @0 @1 @2) is
-     if (@0) goto bb2;
-     bb3:
-     bb2:
-     @3 = PHI <@1(2), @2(3)>
-   */
-}
-
-void
 expr::gen_gimple_transform (FILE *f, const char *label, const char *dest)
 {
   fprintf (f, "{\n");
@@ -546,63 +403,583 @@ capture::gen_gimple_transform (FILE *f,
   fprintf (f, "%s = captures[%s];\n", dest, this->where);
 }
 
+bool
+cmp_operand (operand *o1, operand *o2)
+{
+  if (!o1 || !o2 || o1->type != o2->type)
+    return false;
+
+  if (o1->type == operand::OP_PREDICATE)
+    {
+      predicate *p1 = static_cast<predicate *>(o1);
+      predicate *p2 = static_cast<predicate *>(o2);
+      return strcmp (p1->ident, p2->ident) == 0;
+    }
+  else if (o1->type == operand::OP_EXPR)
+    {
+      expr *e1 = static_cast<expr *>(o1);
+      expr *e2 = static_cast<expr *>(o2);
+      return strcmp (e1->operation->op->id, e2->operation->op->id) == 0;
+    }
+  else
+    return false;
+}
+
 void
-capture::gen_gimple_match (FILE *f, const char *op, const char *label)
+print_flattened_operand (operand *o, FILE *f = stderr)
 {
-  if (this->what)
-    this->what->gen_gimple_match (f, op, label);
-  fprintf (f, "if (!captures[%s])\n"
-	   "  captures[%s] = %s;\n"
-	   "else if (captures[%s] != %s)\n  ",
-	   this->where, this->where, op, this->where, op);
-  gen_gimple_match_fail (f, label);
+  if (o->type == operand::OP_CAPTURE)
+    fprintf (f, "@%s", (static_cast<capture *>(o))->where);
+  else if (o->type == operand::OP_PREDICATE)
+    fprintf (f, "%s", (static_cast<predicate *>(o))->ident);
+  else if (o->type == operand::OP_EXPR)
+    {
+      expr *e = static_cast <expr *>(o);
+      fprintf (f, "%s", e->operation->op->id);
+    }
+  else if (o->type == operand::OP_C_EXPR)
+    fprintf (f, "c_expr");
+  else
+    gcc_unreachable ();
 }
 
+struct dt_node
+{
+  enum dt_type { DT_NODE, DT_OPERAND, DT_TRUE, DT_MATCH, DT_SIMPLIFY };
+
+  enum dt_type type;
+  unsigned level;
+  vec<dt_node *> kids;
+  vec<source_location> match_locations;
+
+  dt_node (enum dt_type type_): type (type_), level (0), kids (vNULL), match_locations (vNULL)  {} 
+  
+  dt_node *append_node (dt_node *); 
+  dt_node *append_op (operand *, dt_node *parent = 0, unsigned pos = 0); 
+  dt_node *append_true_op (dt_node *parent = 0, unsigned pos = 0);
+  dt_node *append_match_op (unsigned, dt_node *parent = 0, unsigned pos = 0);
+  dt_node *append_simplify (simplify *, unsigned, unsigned *); 
 
-static void
-write_nary_simplifiers (FILE *f, vec<simplify *>& simplifiers, unsigned n)
+  virtual void gen_gimple (FILE *) {}
+};
+
+struct dt_operand: public dt_node
+{
+  operand *op;
+  unsigned m_level; // for match
+  dt_operand *parent;
+  unsigned pos;
+  vec<unsigned> temps;
+  static unsigned temp_count;
+ 
+  dt_operand (enum dt_type type, operand *op_, unsigned m_level_, dt_operand *parent_ = 0, unsigned pos_ = 0)
+	: dt_node (type), op (op_), m_level (m_level_), parent (parent_), pos (pos_), temps (vNULL) {}
+
+  virtual void gen_gimple (FILE *);
+  unsigned gen_gimple_predicate (FILE *, const char *);
+  unsigned gen_gimple_match_op (FILE *, const char *);
+
+  unsigned gen_gimple_expr (FILE *, const char *);
+  void gen_gimple_expr_expr (FILE *, expr *);
+  void gen_gimple_expr_fn (FILE *, expr *);
+
+  unsigned gen_generic_expr (FILE *, const char *);
+  void gen_generic_expr_expr (FILE *, expr *, const char *);
+  void gen_generic_expr_fn (FILE *, expr *, const char *);
+};
+
+unsigned dt_operand::temp_count = 0;
+
+struct dt_simplify: public dt_node
+{
+  static const unsigned level_max = UINT_MAX;
+  static const unsigned capture_max = 4;
+  simplify *s; 
+  unsigned pattern_no;
+  unsigned indexes[capture_max]; 
+  
+  dt_simplify (simplify *s_, unsigned pattern_no_, unsigned *indexes_)
+	: dt_node (DT_SIMPLIFY), s (s_), pattern_no (pattern_no_)
+  {
+    for (unsigned i = 0; i < capture_max; ++i)
+      indexes[i] = indexes_[i];
+  }
+
+  virtual void gen_gimple (FILE *f);
+};
+
+struct decision_tree
+{
+  dt_node *root;
+  
+  void insert (struct simplify *, unsigned);
+  void gen_gimple (FILE *f = stderr);
+  void print (FILE *f = stderr);
+
+  decision_tree () { root = new dt_node (dt_node::DT_NODE); }
+
+  static dt_node *insert_operand (dt_node *, operand *, unsigned *indexes, unsigned pos = 0, dt_node *parent = 0); 
+  static dt_node *find_node (vec<dt_node *>&, dt_node *);
+  static bool cmp_node (dt_node *, dt_node *);
+  static void print_node (dt_node *, FILE *f = stderr, unsigned = 0);
+};
+
+bool
+decision_tree::cmp_node (dt_node *n1, dt_node *n2)
+{
+  if (!n1 || !n2 || n1->type != n2->type)
+    return false;
+
+  if (n1 == n2 || n1->type == dt_node::DT_TRUE)
+    return true;
+
+  if (n1->type == dt_node::DT_OPERAND)
+    return cmp_operand ((static_cast<dt_operand *> (n1))->op, (static_cast<dt_operand *> (n2))->op);
+
+  else if (n1->type == dt_node::DT_MATCH)
+    return (static_cast<dt_operand *> (n1))->m_level == (static_cast<dt_operand *> (n2))->m_level;
+
+  else
+    return false;
+}
+
+dt_node *
+decision_tree::find_node (vec<dt_node *>& ops, dt_node *p)
+{
+  for (unsigned i = 0; i < ops.length (); ++i)
+    if (decision_tree::cmp_node (ops[i], p))
+      return ops[i]; 
+  
+  return 0;
+}
+
+dt_node *
+dt_node::append_node (dt_node *n)
 {
-  unsigned label_cnt = 1;
+  dt_node *kid;
 
-  fprintf (f, "\nstatic bool\n"
-	   "gimple_match_and_simplify (code_helper code, tree type");
+  kid = decision_tree::find_node (kids, n);
+  if (kid)
+    return kid;
+
+  kids.safe_push (n);
+  n->level = this->level + 1;
+
+  unsigned len = kids.length ();
+
+  if (len > 1 && kids[len - 2]->type == dt_node::DT_TRUE)
+    {
+      dt_node *p = kids[len - 2];
+      kids[len - 2] = kids[len - 1];
+      kids[len - 1] = p;
+    }
+
+  return n;
+}
+
+dt_node *
+dt_node::append_op (operand *op, dt_node *parent, unsigned pos)
+{
+  dt_operand *parent_ = static_cast<dt_operand *> (parent);
+  dt_node *n = new dt_operand (DT_OPERAND, op, 0, parent_, pos);
+  dt_node *p = append_node (n);
+
+  if (p != n)
+    free (n);
+
+  return p; 
+}
+
+dt_node *
+dt_node::append_true_op (dt_node *parent, unsigned pos)
+{
+  dt_operand *parent_ = static_cast<dt_operand *> (parent);
+  dt_node *n = new dt_operand (DT_TRUE, 0, 0, parent_, pos);
+  dt_node *p = append_node (n);
+
+  if (p != n)
+    free (n);
+
+  return p;
+}
+
+dt_node *
+dt_node::append_match_op (unsigned m_level, dt_node *parent, unsigned pos)
+{
+  dt_operand *parent_ = static_cast<dt_operand *> (parent);
+  dt_node *n = new dt_operand (DT_MATCH, 0, m_level, parent_, pos);
+  dt_node *p = append_node (n);
+
+  if (p != n)
+    free (n);
+
+  return p;
+}
+
+dt_node *
+dt_node::append_simplify (simplify *s, unsigned pattern_no, unsigned *indexes) 
+{
+  dt_node *n = new dt_simplify (s, pattern_no, indexes);
+  return append_node (n);
+}
+
+dt_node *
+decision_tree::insert_operand (dt_node *p, operand *o, unsigned *indexes, unsigned pos, dt_node *parent)
+{
+  dt_node *q;
+
+  if (o->type == operand::OP_CAPTURE)
+    {
+      capture *c = static_cast<capture *> (o);
+      unsigned capt_index = atoi (c->where);
+
+      if (indexes[capt_index] == dt_simplify::level_max)
+	{
+	  indexes[capt_index] = p->level + 1;
+
+	  if (c->what)
+	    return insert_operand (p, c->what, indexes, pos, parent);
+	  else
+	    {
+	      p = p->append_true_op (parent, pos);
+	      return p;
+	    }
+	}
+      else
+	{
+	  p = p->append_match_op (indexes[capt_index], parent, pos);
+	  if (c->what)
+	    return insert_operand (p, c->what, indexes, 0, p);
+	  else
+	    return p;
+	}
+    }
+
+     
+  p = p->append_op (o, parent, pos);
+  q = p;
+
+  if (o->type == operand::OP_EXPR)
+    {
+      expr *e = static_cast<expr *> (o);
+      for (unsigned i = 0; i < e->ops.length (); ++i)
+	q = decision_tree::insert_operand (q, e->ops[i], indexes, i, p);		
+    }
+
+  return q;
+}
+
+
+void
+decision_tree::insert (struct simplify *s, unsigned pattern_no)
+{
+  if (s->match->type != operand::OP_EXPR)
+    return;
+
+  unsigned indexes[dt_simplify::capture_max];
+
+  for (unsigned i = 0; i < dt_simplify::capture_max; ++i)
+    indexes[i] = dt_simplify::level_max;
+
+  dt_node *p = decision_tree::insert_operand (root, s->match, indexes, s->match_location); 
+  p->append_simplify (s, pattern_no, indexes);
+
+  dt_node *temp = new dt_operand (dt_node::DT_OPERAND, s->match, 0);
+  dt_node *q = decision_tree::find_node (root->kids, temp);
+  free (temp); 
+  q->match_locations.safe_push (s->match_location); 
+}
+
+void
+decision_tree::print_node (dt_node *p, FILE *f, unsigned indent)
+{
+  if (p->type == dt_node::DT_NODE)
+    fprintf (f, "root");
+  else
+    {
+      fprintf (f, "|");
+      for (unsigned i = 0; i < indent; i++)
+	fprintf (f, "-");
+
+      if (p->type == dt_node::DT_OPERAND)
+	{
+	  dt_operand *dop = static_cast<dt_operand *>(p);
+	  print_flattened_operand (dop->op, f);
+	} 
+      else if (p->type == dt_node::DT_TRUE)
+	fprintf (f, "true");
+      else if (p->type == dt_node::DT_MATCH)
+	fprintf (f, "match (%u)", ((static_cast<dt_operand *>(p))->m_level));
+      else if (p->type == dt_node::DT_SIMPLIFY)
+	{
+	  dt_simplify *s = static_cast<dt_simplify *> (p);
+	  fprintf (f, "simplify_%u { ", s->pattern_no); 
+	  for (unsigned i = 0; i < dt_simplify::capture_max; ++i)
+	    fprintf (f, "%u, ", s->indexes[i]);
+	  fprintf (f, " } "); 
+	}
+    }      
+
+  fprintf (stderr, " (%p), %u, %u\n", (void *) p, p->level, p->kids.length ());
+
+  for (unsigned i = 0; i < p->kids.length (); ++i)
+    decision_tree::print_node (p->kids[i], f, indent + 2);
+}
+
+
+void
+decision_tree::print (FILE *f)
+{
+  return decision_tree::print_node (root, f);
+}
+
+void
+write_fn_prototype (FILE *f, unsigned n)
+{
+  fprintf (f, "static bool\n"
+          "gimple_match_and_simplify (code_helper code, tree type");
   for (unsigned i = 0; i < n; ++i)
     fprintf (f, ", tree op%d", i);
-  fprintf (f, ", code_helper *res_code, tree *res_ops, gimple_seq *seq, tree (*valueize)(tree))\n"
-	   "{\n");
-  for (unsigned i = 0; i < simplifiers.length (); ++i)
+  fprintf (f, ", code_helper *res_code, tree *res_ops, gimple_seq *seq, tree (*valueize)(tree))\n");
+}
+
+unsigned
+dt_operand::gen_gimple_predicate (FILE *f, const char *opname)
+{
+  predicate *p = static_cast<predicate *> (op);
+
+  fprintf (f, "if (%s (%s))\n", p->ident, opname);
+  fprintf (f, "{\n");
+  return 1;
+}
+
+unsigned
+dt_operand::gen_gimple_match_op (FILE *f, const char *opname)
+{
+  fprintf (f, "if (%s == o%u)\n", opname, m_level);
+  fprintf (f, "{\n");
+  return 1;
+}
+
+void
+dt_operand::gen_gimple_expr_fn (FILE *f, expr *e)
+{
+  unsigned n_ops = e->ops.length ();
+
+  fn_id *op = static_cast <fn_id *> (e->operation->op);
+  fprintf (f, "if (gimple_call_builtin_p (def_stmt, %s))\n", op->id);
+  fprintf (f, "{\n");
+
+  for (unsigned i = 0; i < n_ops; ++i)
     {
-      simplify *s = simplifiers[i];
-      /* ???  This means we can't capture the outermost expression.  */
-      if (s->match->type != operand::OP_EXPR)
-	continue;
-      expr *e = static_cast <expr *> (s->match);
-      if (e->ops.length () != n)
-	continue;
-      char fail_label[16];
-      snprintf (fail_label, 16, "fail%d", label_cnt++);
-      output_line_directive (f, s->match_location);
-      fprintf (f, "  if (code == %s)\n", e->operation->op->id);
-      fprintf (f, "    {\n");
-      fprintf (f, "      tree captures[4] = {};\n");
-      for (unsigned j = 0; j < n; ++j)
-	{
-	  char op[4] = "op0";
-	  op[2] = '0' + j;
-	  e->ops[j]->gen_gimple_match (f, op, fail_label);
+      char child_opname[20];
+      sprintf (child_opname, "t%u", dt_operand::temp_count);
+      temps.safe_push (dt_operand::temp_count++);
+
+      fprintf (f, "tree %s = gimple_call_arg (def_stmt, %u);\n", child_opname, i);
+      fprintf (f, "if ((%s = do_valueize (valueize, %s)) != 0)\n", child_opname, child_opname);
+      fprintf (f, "{\n");
+    } 
+}
+
+void
+dt_operand::gen_gimple_expr_expr (FILE *f, expr *e)
+{
+  unsigned n_ops = e->ops.length (); 
+
+  operator_id *op_id = static_cast <operator_id *> (e->operation->op);
+  
+  if (op_id->code == NOP_EXPR || op_id->code == CONVERT_EXPR)
+    fprintf (f, "if (is_gimple_assign (def_stmt) &&\n"
+                "   (gimple_assign_rhs_code (def_stmt) == %s\n"
+	        "   || CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))))\n", op_id->id);
+  else
+    fprintf (f, "if (is_gimple_assign (def_stmt) && gimple_assign_rhs_code (def_stmt) == %s)\n", op_id->id);
+
+  fprintf (f, "{\n");
+  
+  for (unsigned i = 0; i < n_ops; ++i)
+    {
+      char child_opname[20];
+      sprintf (child_opname, "t%u", dt_operand::temp_count);
+      temps.safe_push (dt_operand::temp_count++);
+
+      fprintf (f, "tree %s = gimple_assign_rhs%u (def_stmt);\n", child_opname, i + 1);
+      fprintf (f, "if ((%s = do_valueize (valueize, %s)) != 0)\n", child_opname, child_opname);
+      fprintf (f, "{\n");
+    }      
+} 
+
+unsigned
+dt_operand::gen_gimple_expr (FILE *f, const char *opname)
+{
+  unsigned i;
+  expr *e = static_cast<expr *> (op);
+
+  fprintf (f, "if (TREE_CODE (%s) == SSA_NAME)\n", opname);
+  fprintf (f, "{\n");
+  
+  fprintf (f, "gimple def_stmt = SSA_NAME_DEF_STMT (%s);\n", opname);
+  (e->operation->op->kind == id_base::CODE) ? gen_gimple_expr_expr (f, e) : gen_gimple_expr_fn (f, e);
+
+  return e->ops.length () + 2;
+}
+
+void
+dt_operand::gen_generic_expr_expr (FILE *f, expr *e, const char *opname)
+{
+  unsigned n_ops = e->ops.length ();
+
+  fprintf (f, "if (TREE_CODE (%s) == %s)\n", opname, e->operation->op->id);
+  fprintf (f, "{\n");
+
+  for (unsigned i = 0; i < n_ops; ++i)
+    {
+      char child_opname[20];
+      sprintf (child_opname, "t%u", dt_operand::temp_count);
+      temps.safe_push (dt_operand::temp_count++);
+
+      fprintf (f, "tree %s = TREE_OPERAND (%s, %u);\n", child_opname, opname, i);
+      fprintf (f, "if ((%s = do_valueize (valueize, %s)) != 0)\n", child_opname, child_opname);
+      fprintf (f, "{\n");
+    }
+}   
+
+void
+dt_operand::gen_generic_expr_fn (FILE *f, expr *e, const char *opname)
+{
+  unsigned n_ops = e->ops.length ();
+  fn_id *op = static_cast <fn_id *> (e->operation->op);
+
+  fprintf (f, "if (TREE_CODE (%s) == CALL_EXPR\n"
+               "    && TREE_CODE (CALL_EXPR_FN (%s)) == ADDR_EXPR\n"
+               "    && TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (%s), 0)) == FUNCTION_DECL\n"
+               "    && DECL_BUILT_IN_CLASS (TREE_OPERAND (CALL_EXPR_FN (%s), 0)) == BUILT_IN_NORMAL\n"
+               "    && DECL_FUNCTION_CODE (TREE_OPERAND (CALL_EXPR_FN (%s), 0)) == %s)\n",
+               opname, opname, opname, opname, opname, op->id);
+  fprintf (f, "  {\n");
+
+  for (unsigned i = 0; i < n_ops; ++i)
+    {
+      char child_opname[20];
+      sprintf (child_opname, "t%u", dt_operand::temp_count);
+      temps.safe_push (dt_operand::temp_count++);
+
+      fprintf (f, "tree %s = CALL_EXPR_ARG (%s, %u);\n", child_opname, opname, i);
+      fprintf (f, "if ((%s = do_valueize (valueize, %s)) != 0)\n", child_opname, child_opname);
+      fprintf (f, "{\n");
+    }
+}
+
+unsigned
+dt_operand::gen_generic_expr (FILE *f, const char *opname)
+{
+  unsigned i;
+  expr *e = static_cast<expr *> (op);
+  (e->operation->op->kind == id_base::CODE) ? gen_generic_expr_expr (f, e, opname) : gen_generic_expr_fn (f, e, opname);
+  return e->ops.length () + 1;
+}
+
+void
+dt_operand::gen_gimple (FILE *f)
+{
+  char opname[20];
+  sprintf (opname, "o%u", level);
+  
+
+  fprintf (f, "{\n");
+
+  fprintf (stderr, "pos = %u\n", pos);
+
+  if (parent->parent == 0)
+    fprintf (f, "tree %s = op%u;\n", opname, pos);
+  else if (parent->type == dt_node::DT_MATCH)
+    fprintf (f, "tree %s = o%u;\n", opname, parent->level);
+  else if (parent->type == dt_node::DT_OPERAND && parent->op->type == operand::OP_EXPR) 
+    fprintf (f, "tree %s = t%u;\n", opname, parent->temps[pos]);
+  else
+    gcc_unreachable ();
+
+  unsigned n_braces = 0;
+ 
+  if (type == DT_OPERAND)
+    switch (op->type)
+      {
+	case operand::OP_PREDICATE:
+	  n_braces = gen_gimple_predicate (f, opname);
+	  break;
+
+	case operand::OP_EXPR:
+	{
+	  expr *e = static_cast<expr *> (op);
+  	  operator_id *op_id = static_cast <operator_id *> (e->operation->op);
+	  enum tree_code code = op_id->code;
+
+	  if (code == REALPART_EXPR || code == IMAGPART_EXPR || code == VIEW_CONVERT_EXPR || code == BIT_FIELD_REF)
+	    n_braces = gen_generic_expr (f, opname);
+
+	  // check for cond_expr, 0th operand -> generic
+	  else if (parent->type == dt_node::DT_OPERAND && parent->op->type == operand::OP_EXPR)
+	    {
+	      e = static_cast<expr *> (parent->op);
+	      op_id = static_cast <operator_id *> (e->operation->op);
+	      n_braces = (op_id->code == COND_EXPR && pos == 0) ? gen_generic_expr (f, opname) : gen_gimple_expr (f, opname);
+	    }
+	  else
+	    n_braces = gen_gimple_expr (f, opname);
 	}
-      if (s->ifexpr)
+	  break;
+
+	default:
+	  gcc_unreachable ();
+      }
+  else if (type == DT_TRUE)
+    ;
+  else if (type == DT_MATCH)
+    n_braces = gen_gimple_match_op (f, opname);
+  else
+    gcc_unreachable ();
+
+  unsigned i;
+
+  for (i = 0; i < kids.length (); ++i)
+    kids[i]->gen_gimple (f);
+
+  for (i = 0; i < n_braces; ++i)
+    fprintf (f, "}\n");
+  
+  fprintf (f, "}\n");
+}
+
+void
+dt_simplify::gen_gimple (FILE *f)
+{
+
+  char *fail_label = 0;
+
+  fprintf (f, "/* simplify %u */\n", pattern_no);
+
+  fprintf (f, "{\n");
+  fprintf (f, "tree captures[4] = {};\n");
+
+  for (unsigned i = 0; i < dt_simplify::capture_max; ++i)
+    if (indexes[i] != dt_simplify::level_max) 
+      fprintf (f, "captures[%u] = o%u;\n", i, indexes[i]); 
+
+  if (s->ifexpr)
 	{
 	  output_line_directive (f, s->ifexpr_location);
-	  fprintf (f, "  if (!(");
+	  fprintf (f, "if (");
 	  s->ifexpr->gen_gimple_transform (f, fail_label, NULL);
-	  fprintf (f, ")) goto %s;\n", fail_label);
+	  fprintf (f, ")\n");
+	  fprintf (f, "{\n");
 	}
       output_line_directive (f, s->result_location);
+
       if (s->result->type == operand::OP_EXPR)
 	{
-	  e = static_cast <expr *> (s->result);
-	  fprintf (f, "   *res_code = %s;\n", e->operation->op->id);
+	  expr *e = static_cast <expr *> (s->result);
+	  fprintf (f, "*res_code = %s;\n", e->operation->op->id);
 	  for (unsigned j = 0; j < e->ops.length (); ++j)
 	    {
 	      char dest[32];
@@ -611,26 +988,64 @@ write_nary_simplifiers (FILE *f, vec<sim
 	    }
 	  /* Re-fold the toplevel result.  It's basically an embedded
 	     gimple_build w/o actually building the stmt.  */
-	  fprintf (f, "   gimple_resimplify%d (seq, res_code, type, "
+	  fprintf (f, "gimple_resimplify%d (seq, res_code, type, "
 		   "res_ops, valueize);\n", e->ops.length ());
 	}
       else if (s->result->type == operand::OP_CAPTURE
 	       || s->result->type == operand::OP_C_EXPR)
 	{
 	  s->result->gen_gimple_transform (f, fail_label,
-					   "      res_ops[0]");
-	  fprintf (f, "      *res_code = TREE_CODE (res_ops[0]);\n");
+					   "res_ops[0]");
+	  fprintf (f, "*res_code = TREE_CODE (res_ops[0]);\n");
 	}
       else
 	gcc_unreachable ();
-      fprintf (f, "      return true;\n");
-      fprintf (f, "    }\n");
-      fprintf (f, "%s:\n", fail_label);
+
+      fprintf (f, "return true;\n");
+      if (s->ifexpr)
+	fprintf (f, "}\n");
+
+  fprintf (f, "}\n");
+}
+
+
+
+void
+decision_tree::gen_gimple (FILE *f)
+{
+  write_fn_prototype (f, 1);
+  fprintf (f, "{ return gimple_match_and_simplify (code, type, op0, NULL_TREE, NULL_TREE, res_code, res_ops, seq, valueize); }\n\n");
+
+  write_fn_prototype (f, 2);
+  fprintf (f, "{ return gimple_match_and_simplify (code, type, op0, op1, NULL_TREE, res_code, res_ops, seq, valueize); }\n\n");
+
+  write_fn_prototype (f, 3);
+  fprintf (f, "{\n");
+
+  for (unsigned i = 0; i < root->kids.length (); i++)
+    {
+      dt_operand *dop = static_cast<dt_operand *>(root->kids[i]);
+      expr *e = static_cast<expr *>(dop->op);
+
+      for (unsigned j = 0; j < dop->match_locations.length (); ++j)
+	output_line_directive (f, dop->match_locations[j]);
+
+      if (i)
+        fprintf (f, "else ");
+      fprintf (f, "if (code == %s)\n", e->operation->op->id);
+      fprintf (f, "{\n");
+
+      for (unsigned j = 0; j < dop->kids.length (); ++j)
+	dop->kids[j]->gen_gimple (f);
+
+      fprintf (f, "}\n");
     }
-  fprintf (f, "  return false;\n");
+
+  fprintf (f, "return false;\n");
   fprintf (f, "}\n");
 }
 
+
 static void
 outline_c_exprs (FILE *f, struct operand *op)
 {
@@ -712,10 +1127,6 @@ write_gimple (FILE *f, vec<simplify *>&
   /* Outline complex C expressions to helper functions.  */
   for (unsigned i = 0; i < simplifiers.length (); ++i)
     outline_c_exprs (stdout, simplifiers[i]->result);
-
-  write_nary_simplifiers (f, simplifiers, 1);
-  write_nary_simplifiers (f, simplifiers, 2);
-  write_nary_simplifiers (f, simplifiers, 3);
 }
 
 
@@ -1043,7 +1454,14 @@ main(int argc, char **argv)
     }
   while (1);
 
+  decision_tree dt;
+  for (unsigned i = 0; i < simplifiers.length (); ++i)
+    dt.insert (simplifiers[i], i);
+
+  dt.print (stderr);
+ 
   write_gimple (stdout, simplifiers);
+  dt.gen_gimple (stdout);
 
   cpp_finish (r, NULL);
   cpp_destroy (r);
Index: gcc/gimple-match-head.c
===================================================================
--- gcc/gimple-match-head.c	(revision 211732)
+++ gcc/gimple-match-head.c	(working copy)
@@ -706,3 +706,10 @@ gimple_match_and_simplify (gimple_stmt_i
   return true;
 }
 
+static tree 
+do_valueize (tree (*valueize)(tree), tree op)
+{
+  if (valueize && TREE_CODE (op) == SSA_NAME)
+    return valueize (op);
+  return op;
+}

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]