On Fri, Jul 11, 2014 at 8:29 PM, Prathamesh Kulkarni
<bilbotheelffri...@gmail.com> wrote:
> On 7/11/14, Richard Biener <richard.guent...@gmail.com> wrote:
>> On Thu, Jul 10, 2014 at 8:05 PM, Prathamesh Kulkarni
>> <bilbotheelffri...@gmail.com> wrote:
>>> Hi,
>>> I have attempted to add syntax for symbol to denote multiple
>>> operators.
>>>
>>> I tried it with few bogus patterns and it appears to work.... hopefully
>>> -:)
>>> eg: (bogus pattern):
>>> (for op in plus minus
>>> (match_and_simplify
>>> (op @0 @1)
>>> (op @0 @0)))
>>>
>>> generates following patterns:
>>> (plus @0 @1) -> (plus @0 @0) // simplify_0
>>> (plus @0 @1) -> (mult @0 @0) // simplify_1
>>> (mult @0 @1) -> (plus @0 @0) // simplify_2
>>> (mult @0 @1) -> (mult @0 @0) // simplify_3
>>
>> s/mult/minus/? I think it should only generate
>>
>> (plus @0 @1) -> (plus @0 @0)
>> (minus @0 @1) -> (minus @0 @0)
>>
>> to get the what you write we should need to write
>>
>> (for op1 in plus minus
>> (for op2 in plus minus
>> (match_and_simplify
>> (op1 @0 @1)
>> (op2 @0 @0))))
>>
>>> root (0xab6b10), 0, 2
>>> |--(PLUS_EXPR) (0xab6b30), 1, 1
>>> |----true (0xab6ba0), 2, 1
>>> |------true (0xab6c10), 3, 2
>>> |--------simplify_0 { 0xab6ba0, 0xab6c10, (nil), (nil), } (0xab6c80), 4,
>>> 0
>>> |--------simplify_1 { 0xab6ba0, 0xab6c10, (nil), (nil), } (0xab6d40), 4,
>>> 0
>>> |--(MULT_EXPR) (0xab6d00), 1, 1
>>> |----true (0xab6d90), 2, 1
>>> |------true (0xab6e00), 3, 2
>>> |--------simplify_2 { 0xab6d90, 0xab6e00, (nil), (nil), } (0xab6e70), 4,
>>> 0
>>> |--------simplify_3 { 0xab6d90, 0xab6e00, (nil), (nil), } (0xab6f30), 4,
>>> 0
>>>
>>> * Changes to rest of the code:
>>> a) commutating patterns was interfering with this, because
>>> parse_match_and_simplify, immediately commutated match operand. Symbol
>>> should be replaced by operators before commutating. This required
>>> adjusting simplify (back to operand *match), and commutating is done
>>> in new function lower_commutative. Ideally this should be done during
>>> insertion in decision tree ?
>>
>> Yes, commutating should be done by inserting a pattern multiple
>> times with adjusted AST walk order.
>>
>>> b) adjustments required to e_operation constructor, so it doesn't
>>> call fatal, when it does not find id to be in the hash table.
>>
>> Eventually just temporarily insert a new operator in the hash table
>> when parsing comes along a (for OP ...? That is, add a new kind,
>> USER and just re-use base->id?
>>
>>> * Caveats
>>> a) new e_operation constructor taking id_base * argument. Not sure
>>> if that's required.
>>> b) e_operation::user_id denotes user-defined identifier (<opname>),
>>> a rather apologetic name ...
>>> c) Similar to commutate(), replace_user_id() does not clone AST's.
>>> So we have multiple AST's sharing same nodes.
>>
>> I wonder if we want to parse the 'for' into an AST node instead,
>> thus not expand it on-the-fly. Applying could then happen during
>> DT insertion. Or as a separate lowering like you introduce
>> lower_commutative - that looks cleaner.
>>
>> Or if we can simply parse the match-and-simplify multiple times, with
>> the for op replaces, using _cpp_backup_tokens. Ok, no - that
>> sounds like too much of a hack.
>>
>>> * add multiple symbols ?
>>> should we have
>>> (for <opname> in operator-list1, <opname2> in operator-list2
>>> (match_and_simplify
>>> ...))
>>> or have nested for ?
>>> (for <opname> in operator-list1
>>> (for <opname2> in operator-list2
>>> (match_and_simplify
>>> ....)))
>>
>> It depends on the desired semantics. It's a lot clearer with
>> single opname for only (but then we eventually need nested for).
>>
>>> * we don't detect functions with wrong arguments
>>> for example, we dont give error on:
>>> (built_in_sqrt @0 @1)
>>> I guess that's because we don't have an easy way to figure out
>>> number of arguments a function expects ?
>>> (is there a built-in equivalent of tree_code_length[] ?)
>>
>> Yeah, the function stuff is still very simplistic and no, there isn't
>> any easy way of extracting the number of expected arguments
>> from builtins.def (it's encoded in the type). The easiest way
>> would be to change builtins.def to add a number-of-args argument ...
>>
>> Let's just defer that issue.
>>
>>
>> As for the patch, we shouldn't do the cartesian_product - that's
>> hardly ever what the user intends and it means there isn't any
>> way of repeating the same pattern for multiple operators.
>>
>> A common use for 'for' would be (for OP in ne eq (...)) as most
>> equality foldings are valid for ne and eq. Another is
>> for the various division kinds we have - trunc_div ceil_div floor_div
>> and round_div (same for mod):
>>
>> (for op in trunc_div ceil_div floor_div round_div
>> (match_and_simplify
>> (op @0 integer_onep)
>> @0))
>>
>> (good example for match.pd to exercise the code)
>>
>> Can you fix the cartesian product thing (it should only simplify the
>> patch)?
> This version of the patch, removes cartesian_product, and reuses
> id_base::id for user-defined symbols.
>
> eg:
> (for op in plus minus
> (match_and_simplify
> (op (op @0 @1) @2)
> (op @0 @0)))
>
> generates following patterns:
> (plus (plus @0 @1) @2) -> (plus @0 @0)
> (minus (minus @0 @1) @2) -> (minus @0 @0)
> Is this correct ?
>
> I added the (for op in trunc_div floor_div ceil_div round_div ..)
> pattern in match.pd
> This works for trunc_div, I am not sure how to generate
> floor_div/ceil_div/round_div
> from C test-case.
>
> I added the following rotate pattern in match.pd:
> /* (x << CNT1) OP (x >> CNT2) -> x r<< CNT1 OP being +, |, ^ */
> (for op in plus bit_ior bit_xor
> (match_and_simplify
> (op:c (lshift @0 INTEGER_CST_P@1) (rshift @0 INTEGER_CST_P@2))
> if (tree_fits_uhwi_p (@1) && tree_fits_uhwi_p (@2)
> && tree_to_uhwi (@1) + tree_to_uhwi (@2) == TYPE_PRECISION (type))
> (lrotate @0 @1)))
>
> Is this correct ?
>
> * genmatch.c (id_base::id_kind): New enum value USER_DEFINED.
> (e_operation::e_operation): Add default argument add_new_id.
> (simplify): Remove member matchers.
> (simplify): New member match.
> (print_matches): Adjust to changes in simplify.
> (decision_tree::insert): Likewise.
> (parse_match_and_simplify): Likewise.
> (lower_commutative): New function.
> (check_operator): Likewise.
> (replace_id): Likewise.
> (eat_ident): Likewise.
> (parse_for): Likewise.
> (parse_expr): Call check_operator.
> (main): Call parse_for, lower_commutative.
>
> * match.pd: Add pattern for div, and rotate pattern.
>
> [gcc/testsuite/gcc.dg/tree-ssa]
> * match-rotate.c: New test-case.
Added nested for, and adjusted few constant folding patterns in
match.pd to use for.
Unfortunately, I haven't been able to figure out how to generate
CEIL_DIV_EXPR, FLOOR_DIV_EXPR,
ROUND_DIV_EXPR, from a c test-case. I came across this link:
https://gcc.gnu.org/bugzilla/show_bug.cgi?format=multiple&id=46679
It says it's not possible to generate floor/ceil/round from C.
In that case how do we test for this (maybe another front-end
generates floor/ceil ?)
* genmatch.c (id_base::id_kind): Add new enum value USER_DEFINED.
(e_operation::e_operation): New default argument add_new_id. Adjust
to add id in hash table.
(simplify): Remove matchers member. New member match.
(print_matches): Adjust to changes in simplify.
(decision_tree::insert): Likewise.
(lower_commutative): New function.
(check_operator): Likewise.
(replace_id): Likewise.
(eat_ident): Likewise.
(parse_for): Likewise.
(parse_pattern): Likewise.
(check_no_user_id): Likewise.
(check_no_user_id): Likewise, overloaded to take simplify as first argument.
(parse_expr): Call check_operator.
(main): call parse_pattern, lower_commutative, check_no_user_id.
* match.pd: Adjust few constant folding patterns to use for.
[gcc/testsuite/gcc.dg/tree-ssa]
* match-rotate.c: New test-case.
Thanks and Regards,
Prathamesh
>
> Thanks and Regards,
> Prathamesh
>
>>
>> Thanks,
>> Richard.
>>
>>> * genmatch.c (e_operation::e_operation): New constructor.
>>> (e_operation::user_id): New member.
>>> (e_operation::get_op): New member function.
>>> (simplify::matchers): Remove.
>>> (simplify::match): New member.
>>> (lower_commutative): New function.
>>> (check_operator): Likewise.
>>> (replace_user_id): Likewise.
>>> (decision_tree::insert): Adjust to changes in simplify.
>>> (eat_ident): New function.
>>> (parse_expr): Call to check_operator.
>>> (parse_for): New function.
>>> (main): Add calls to parse_for, lower_commutative.
>>>
>>> Thanks and Regards,
>>> Prathamesh
>>
Index: gcc/genmatch.c
===================================================================
--- gcc/genmatch.c (revision 212366)
+++ gcc/genmatch.c (working copy)
@@ -116,7 +116,7 @@ END_BUILTINS
struct id_base : typed_free_remove<id_base>
{
- enum id_kind { CODE, FN } kind;
+ enum id_kind { CODE, FN, USER_DEFINED } kind;
id_base (id_kind, const char *);
@@ -135,6 +135,7 @@ id_base::hash (const value_type *op)
{
return op->hashval;
}
+
inline int
id_base::equal (const value_type *op1,
const compare_type *op2)
@@ -169,6 +170,7 @@ struct fn_id : public id_base
enum built_in_function fn;
};
+
static void
add_operator (enum tree_code code, const char *id,
const char *tcc, unsigned nargs)
@@ -217,7 +219,7 @@ struct predicate : public operand
};
struct e_operation {
- e_operation (const char *id, bool is_commutative_ = false);
+ e_operation (const char *id, bool is_commutative_ = false, bool add_new_id = true);
id_base *op;
bool is_commutative;
};
@@ -254,11 +256,10 @@ struct capture : public operand
virtual void gen_transform (FILE *f, const char *, bool);
};
-
-e_operation::e_operation (const char *id, bool is_commutative_)
+e_operation::e_operation (const char *id, bool is_commutative_, bool add_new_id)
{
- id_base tem (id_base::CODE, id);
is_commutative = is_commutative_;
+ id_base tem (id_base::CODE, id);
op = operators.find_with_hash (&tem, tem.hashval);
if (op)
@@ -287,19 +288,23 @@ e_operation::e_operation (const char *id
return;
}
- fatal ("expected operator, got %s", id);
+ if (add_new_id == false)
+ fatal ("%s is not an operator/built-in function", id);
+
+ op = new id_base (id_base::USER_DEFINED, id);
+ operators.find_slot_with_hash (op, op->hashval, INSERT);
}
struct simplify {
simplify (const char *name_,
- vec<operand *> matchers_, source_location match_location_,
+ operand *match_, source_location match_location_,
struct operand *ifexpr_, source_location ifexpr_location_,
struct operand *result_, source_location result_location_)
- : name (name_), matchers (matchers_), match_location (match_location_),
+ : name (name_), match (match_), match_location (match_location_),
ifexpr (ifexpr_), ifexpr_location (ifexpr_location_),
result (result_), result_location (result_location_) {}
const char *name;
- vec<operand *> matchers; // vector to hold commutative expressions
+ operand *match;
source_location match_location;
struct operand *ifexpr;
source_location ifexpr_location;
@@ -452,19 +457,9 @@ print_operand (operand *o, FILE *f = std
void
print_matches (struct simplify *s, FILE *f = stderr)
{
- if (s->matchers.length () == 1)
- return;
-
fprintf (f, "for expression: ");
- print_operand (s->matchers[0], f); // s->matchers[0] is equivalent to original expression
+ print_operand (s->match, f);
putc ('\n', f);
-
- fprintf (f, "commutative expressions:\n");
- for (unsigned i = 0; i < s->matchers.length (); ++i)
- {
- print_operand (s->matchers[i], f);
- putc ('\n', f);
- }
}
void
@@ -552,6 +547,104 @@ commutate (operand *op)
return ret;
}
+void
+lower_commutative (simplify *s, vec<simplify *>& simplifiers)
+{
+ vec<operand *> matchers = commutate (s->match);
+ for (unsigned i = 0; i < matchers.length (); ++i)
+ {
+ simplify *ns = new simplify (s->name, matchers[i], s->match_location,
+ s->ifexpr, s->ifexpr_location,
+ s->result, s->result_location);
+ simplifiers.safe_push (ns);
+ }
+}
+
+void
+check_operator (id_base *op, unsigned n_ops, const cpp_token *token = 0)
+{
+ if (!op)
+ return;
+
+ if (op->kind != id_base::CODE)
+ return;
+
+ operator_id *opr = static_cast<operator_id *> (op);
+ if (opr->get_required_nargs () == n_ops)
+ return;
+
+ if (token)
+ fatal_at (token, "%s expects %u operands, got %u operands", opr->id, opr->get_required_nargs (), n_ops);
+ else
+ fatal ("%s expects %u operands, got %u operands", opr->id, opr->get_required_nargs (), n_ops);
+}
+
+operand *
+replace_id (operand *o, const char *user_id, const char *oper)
+{
+ if (o->type == operand::OP_CAPTURE)
+ {
+ capture *c = static_cast<capture *> (o);
+ if (!c->what)
+ return c;
+ capture *nc = new capture (c->where, replace_id (c->what, user_id, oper));
+ return nc;
+ }
+
+ if (o->type != operand::OP_EXPR)
+ return o;
+
+ expr *e = static_cast<expr *> (o);
+ expr *ne;
+
+ if (e->operation->op->kind == id_base::USER_DEFINED && strcmp (e->operation->op->id, user_id) == 0)
+ {
+ struct e_operation *operation = new e_operation (oper, e->operation->is_commutative, false);
+ check_operator (operation->op, e->ops.length ());
+ ne = new expr (operation);
+ }
+ else
+ ne = new expr (e->operation);
+
+ for (unsigned i = 0; i < e->ops.length (); ++i)
+ ne->append_op (replace_id (e->ops[i], user_id, oper));
+
+ return ne;
+}
+
+void
+check_no_user_id (operand *o)
+{
+ if (o->type == operand::OP_CAPTURE)
+ {
+ capture *c = static_cast<capture *> (o);
+ if (c->what && c->what->type == operand::OP_EXPR)
+ {
+ o = c->what;
+ goto check_expr;
+ }
+ return;
+ }
+
+ if (o->type != operand::OP_EXPR)
+ return;
+
+check_expr:
+ expr *e = static_cast<expr *> (o);
+ if (e->operation->op->kind == id_base::USER_DEFINED)
+ fatal ("%s is not defined in for", e->operation->op->id);
+
+ for (unsigned i = 0; i < e->ops.length (); ++i)
+ check_no_user_id (e->ops[i]);
+}
+
+void
+check_no_user_id (simplify *s)
+{
+ check_no_user_id (s->match);
+ check_no_user_id (s->result);
+}
+
/* Code gen off the AST. */
void
@@ -828,17 +921,14 @@ decision_tree::insert (struct simplify *
{
dt_operand *indexes[dt_simplify::capture_max];
- for (unsigned i = 0; i < s->matchers.length (); ++i)
- {
- if (s->matchers[i]->type != operand::OP_EXPR)
- continue;
+ if (s->match->type != operand::OP_EXPR)
+ return;
- for (unsigned j = 0; j < dt_simplify::capture_max; ++j)
- indexes[j] = 0;
+ for (unsigned j = 0; j < dt_simplify::capture_max; ++j)
+ indexes[j] = 0;
- dt_node *p = decision_tree::insert_operand (root, s->matchers[i], indexes);
- p->append_simplify (s, pattern_no, indexes);
- }
+ dt_node *p = decision_tree::insert_operand (root, s->match, indexes);
+ p->append_simplify (s, pattern_no, indexes);
}
void
@@ -1707,6 +1797,16 @@ get_ident (cpp_reader *r)
return (const char *)CPP_HASHNODE (token->val.node.node)->ident.str;
}
+static void
+eat_ident (cpp_reader *r, const char *s)
+{
+ const cpp_token *token = expect (r, CPP_NAME);
+ const char *t = (const char *) CPP_HASHNODE (token->val.node.node)->ident.str;
+
+ if (strcmp (s, t))
+ fatal_at (token, "expected %s got %s\n", s, t);
+}
+
/* Read the next token from R and assert it is of type CPP_NUMBER and
return its value. */
@@ -1735,6 +1835,7 @@ parse_capture (cpp_reader *r, operand *o
return new capture (get_number (r), op);
}
+
/* Parse
expr = (operation[capture] op...) */
static struct operand *
@@ -1774,13 +1875,7 @@ parse_expr (cpp_reader *r)
const cpp_token *token = peek (r);
if (token->type == CPP_CLOSE_PAREN)
{
- if (e->operation->op->kind == id_base::CODE)
- {
- operator_id *opr = static_cast <operator_id *> (e->operation->op);
- if (e->ops.length () != opr->get_required_nargs ())
- fatal_at (token, "got %d operands instead of the required %d",
- e->ops.length (), opr->get_required_nargs ());
- }
+ check_operator (e->operation->op, e->ops.length (), token);
if (is_commutative)
{
if (e->ops.length () == 2)
@@ -1877,6 +1972,7 @@ parse_op (cpp_reader *r)
return op;
}
+
/* Parse
(define_match_and_simplify "<ident>"
<op> <op>) */
@@ -1912,10 +2008,44 @@ parse_match_and_simplify (cpp_reader *r,
ifexpr = parse_c_expr (r, CPP_OPEN_PAREN);
}
token = peek (r);
- return new simplify (id, commutate (match), match_location,
+ return new simplify (id, match, match_location,
ifexpr, ifexpr_location, parse_op (r), token->src_loc);
}
+void
+parse_for (cpp_reader *r, source_location match_location, vec<simplify *>& simplifiers)
+{
+ const char *user_id = get_ident (r);
+ eat_ident (r, "in");
+ void parse_pattern (cpp_reader *, vec<simplify *>&);
+
+ vec<const char *> opers = vNULL;
+
+ while (1)
+ {
+ const cpp_token *token = peek (r);
+ if (token->type != CPP_NAME)
+ break;
+ opers.safe_push (get_ident (r));
+ }
+
+ vec<simplify *> for_simplifiers = vNULL;
+ parse_pattern (r, for_simplifiers);
+
+ for (unsigned i = 0; i < opers.length (); ++i)
+ {
+ for (unsigned j = 0; j < for_simplifiers.length (); ++j)
+ {
+ simplify *s = for_simplifiers[j];
+ operand *match_op = replace_id (s->match, user_id, opers[i]);
+ operand *result_op = replace_id (s->result, user_id, opers[i]);
+ simplify *ns = new simplify (s->name, match_op, s->match_location,
+ s->ifexpr, s->ifexpr_location,
+ result_op, s->result_location);
+ simplifiers.safe_push (ns);
+ }
+ }
+}
static size_t
round_alloc_size (size_t s)
@@ -1923,6 +2053,23 @@ round_alloc_size (size_t s)
return s;
}
+void
+parse_pattern (cpp_reader *r, vec<simplify *>& simplifiers)
+{
+ /* All clauses start with '('. */
+ eat_token (r, CPP_OPEN_PAREN);
+ const cpp_token *token = peek (r);
+ const char *id = get_ident (r);
+ if (strcmp (id, "match_and_simplify") == 0)
+ simplifiers.safe_push (parse_match_and_simplify (r, token->src_loc));
+ else if (strcmp (id, "for") == 0)
+ parse_for (r, token->src_loc, simplifiers);
+ else
+ fatal_at (token, "expected 'match_and_simplify' or 'for'");
+
+ eat_token (r, CPP_CLOSE_PAREN);
+}
+
int
main(int argc, char **argv)
{
@@ -1974,42 +2121,35 @@ main(int argc, char **argv)
vec<simplify *> simplifiers = vNULL;
- do
- {
- token = peek (r);
- if (token->type == CPP_EOF)
- break;
-
- /* All clauses start with '('. */
- eat_token (r, CPP_OPEN_PAREN);
-
- const char *id = get_ident (r);
- if (strcmp (id, "match_and_simplify") == 0)
- simplifiers.safe_push (parse_match_and_simplify (r, token->src_loc));
- else
- fatal_at (token, "expected 'match_and_simplify'");
+ while (peek (r)->type != CPP_EOF)
+ parse_pattern (r, simplifiers);
- eat_token (r, CPP_CLOSE_PAREN);
+ for (unsigned i = 0; i < simplifiers.length (); ++i)
+ {
+ fprintf (stderr, "pattern = %u\n", i);
+ check_no_user_id (simplifiers[i]);
}
- while (1);
-
+ vec<simplify *> out_simplifiers = vNULL;
for (unsigned i = 0; i < simplifiers.length (); ++i)
- print_matches (simplifiers[i]);
+ lower_commutative (simplifiers[i], out_simplifiers);
+
+ for (unsigned i = 0; i < out_simplifiers.length (); ++i)
+ print_matches (out_simplifiers[i]);
decision_tree dt;
- for (unsigned i = 0; i < simplifiers.length (); ++i)
- dt.insert (simplifiers[i], i);
+ for (unsigned i = 0; i < out_simplifiers.length (); ++i)
+ dt.insert (out_simplifiers[i], i);
dt.print (stderr);
if (gimple)
{
- write_header (stdout, simplifiers, "gimple-match-head.c");
+ write_header (stdout, out_simplifiers, "gimple-match-head.c");
dt.gen_gimple (stdout);
}
else
{
- write_header (stdout, simplifiers, "generic-match-head.c");
+ write_header (stdout, out_simplifiers, "generic-match-head.c");
dt.gen_generic (stdout);
}
Index: gcc/match.pd
===================================================================
--- gcc/match.pd (revision 212366)
+++ gcc/match.pd (working copy)
@@ -22,29 +22,26 @@ along with GCC; see the file COPYING3.
<http://www.gnu.org/licenses/>. */
/* Simple constant foldings to substitute gimple_fold_stmt_to_constant_2. */
-(match_and_simplify
- (plus @0 integer_zerop)
- @0)
-(match_and_simplify
- (pointer_plus @0 integer_zerop)
- @0)
-(match_and_simplify
- (minus @0 integer_zerop)
- @0)
+(for op in plus pointer_plus minus bit_ior bit_xor
+ (match_and_simplify
+ (op @0 integer_zerop)
+ @0))
+
(match_and_simplify
(minus @0 @0)
{ build_zero_cst (type); })
+
(match_and_simplify
(mult @0 integer_zerop@1)
@1)
-(match_and_simplify
- (mult @0 integer_onep)
- @0)
+
/* Make sure to preserve divisions by zero. This is the reason why
we don't simplify x / x to 1 or 0 / x to 0. */
-(match_and_simplify
- (trunc_div @0 integer_onep)
- @0)
+(for op in mult trunc_div ceil_div floor_div round_div
+ (match_and_simplify
+ (op @0 integer_onep)
+ @0))
+
(match_and_simplify
(trunc_mod @0 integer_onep)
{ build_zero_cst (type); })
@@ -55,9 +52,6 @@ along with GCC; see the file COPYING3.
if (!integer_zerop (@1))
@0)
(match_and_simplify
- (bit_ior @0 integer_zerop)
- @0)
-(match_and_simplify
(bit_ior @0 integer_all_onesp@1)
@1)
(match_and_simplify
@@ -67,9 +61,6 @@ along with GCC; see the file COPYING3.
(bit_and @0 integer_zerop@1)
@1)
(match_and_simplify
- (bit_xor @0 integer_zerop)
- @0)
-(match_and_simplify
(bit_xor @0 @0)
{ build_zero_cst (type); })
/* tree-ssa/ifc-pr44710.c requires a < b ? c : d to fold to 1.
@@ -358,6 +349,15 @@ along with GCC; see the file COPYING3.
if (INTEGRAL_TYPE_P (TREE_TYPE (@0)))
{ build_int_cst (type, 0); })
+/* (x << CNT1) OP (x >> CNT2) -> x r<< CNT1 OP being +, |, ^ */
+(for op in plus bit_ior bit_xor
+(match_and_simplify
+ (op:c (lshift @0 INTEGER_CST_P@1) (rshift @0 INTEGER_CST_P@2))
+ if (tree_fits_uhwi_p (@1) && tree_fits_uhwi_p (@2)
+ && tree_to_uhwi (@1) + tree_to_uhwi (@2) == TYPE_PRECISION (type))
+ (lrotate @0 @1)))
+
+
/* ????s
We cannot reasonably match vector CONSTRUCTORs or vector constants
Index: gcc/testsuite/gcc.dg/tree-ssa/match-rotate.c
===================================================================
--- gcc/testsuite/gcc.dg/tree-ssa/match-rotate.c (revision 0)
+++ gcc/testsuite/gcc.dg/tree-ssa/match-rotate.c (working copy)
@@ -0,0 +1,44 @@
+/* { dg-do compile } */
+/* { dg-options "-O -fdump-tree-forwprop1-details" } */
+
+unsigned char
+rotate_1 (unsigned char x)
+{
+ unsigned char t1 = x << 5;
+ unsigned char t2 = x >> 3;
+ unsigned char rotate_1_val = t1 + t2;
+ return rotate_1_val;
+}
+/* { dg-final { scan-tree-dump "gimple_match_and_simplified to rotate_1_val_\\d\+ = x_\\d\+\\(D\\) r<< 5" "forwprop1" } } */
+
+unsigned char
+rotate_2 (unsigned char x)
+{
+ unsigned char t1 = x << 4;
+ unsigned char t2 = x >> 3;
+ unsigned char rotate_2_val = t1 + t2;
+ return rotate_2_val;
+}
+/* { dg-final { scan-tree-dump-not "gimple_match_and_simplified to rotate_2_val_\\d\+ = x_\\d\+\\(D\\) r<< 5" "forwprop1" } } */
+
+unsigned char
+rotate_3 (unsigned char x)
+{
+ unsigned char t1 = x << 5;
+ unsigned char t2 = x >> 3;
+ unsigned char rotate_3_val = t1 | t2;
+ return rotate_3_val;
+}
+/* { dg-final { scan-tree-dump "gimple_match_and_simplified to rotate_3_val_\\d\+ = x_\\d\+\\(D\\) r<< 5" "forwprop1" } } */
+
+unsigned char
+rotate_4 (unsigned char x)
+{
+ unsigned char t1 = x << 5;
+ unsigned char t2 = x >> 3;
+ unsigned char rotate_4_val = t1 ^ t2;
+ return rotate_4_val;
+}
+/* { dg-final { scan-tree-dump "gimple_match_and_simplified to rotate_4_val_\\d\+ = x_\\d\+\\(D\\) r<< 5" "forwprop1" } } */
+
+/* { dg-final { cleanup-tree-dump "forwprop1" } } */
