On Sat, Jul 23, 2011 at 04:59, Richard Guenther
<richard.guent...@gmail.com> wrote:
> On Sat, Jul 23, 2011 at 1:01 AM, Sebastian Pop <seb...@gmail.com> wrote:
>> The CLAST produced by CLooG-ISL contains an assignment and GCC chokes
>> on it. The exact CLAST contains an assignment followed by an if:
>>
>> scat_1 = max(0,ceild(T_4-7,8));
>> if (scat_1 <= min(1,floord(T_4-1,8))) {
>> S7(scat_1);
>> }
>>
>> This is equivalent to a loop that iterates only once, and so CLooG
>> generates an assignment followed by an if instead of a loop. This is
>> an important optimization that was improved in ISL, that allows
>> if-conversion: imagine GCC having to figure out that a loop like the
>> following actually iterates only once, and can be converted to an if:
>>
>> for (scat_1 = max(0,ceild(T_4-7,8)); scat_1 <= min(1,floord(T_4-1,8));
>> scat_1++)
>> S7(scat_1);
>>
>> This patch implements the translation of CLAST assignments.
>> Bootstrapped and tested on amd64-linux.
>
> Ok if Tobias is fine with it.
Tobias, could you please have a look at this patch?
Thanks,
Sebastian
>
> Thanks,
> Richard.
>
>> Sebastian
>>
>> 2011-07-22 Sebastian Pop <sebastian....@amd.com>
>>
>> PR middle-end/48648
>> * graphite-clast-to-gimple.c (clast_get_body_of_loop): Handle
>> CLAST assignments.
>> (translate_clast): Same.
>> (translate_clast_assignment): New.
>>
>> * gcc.dg/graphite/id-pr48648.c: New.
>> ---
>> gcc/ChangeLog | 8 ++++
>> gcc/graphite-clast-to-gimple.c | 49
>> ++++++++++++++++++++++++++++
>> gcc/testsuite/ChangeLog | 5 +++
>> gcc/testsuite/gcc.dg/graphite/id-pr48648.c | 21 ++++++++++++
>> 4 files changed, 83 insertions(+), 0 deletions(-)
>> create mode 100644 gcc/testsuite/gcc.dg/graphite/id-pr48648.c
>>
>> diff --git a/gcc/ChangeLog b/gcc/ChangeLog
>> index 9cfa21b..303c9c9 100644
>> --- a/gcc/ChangeLog
>> +++ b/gcc/ChangeLog
>> @@ -1,3 +1,11 @@
>> +2011-07-22 Sebastian Pop <sebastian....@amd.com>
>> +
>> + PR middle-end/48648
>> + * graphite-clast-to-gimple.c (clast_get_body_of_loop): Handle
>> + CLAST assignments.
>> + (translate_clast): Same.
>> + (translate_clast_assignment): New.
>> +
>> 2011-07-21 Sebastian Pop <sebastian....@amd.com>
>>
>> PR middle-end/47654
>> diff --git a/gcc/graphite-clast-to-gimple.c b/gcc/graphite-clast-to-gimple.c
>> index ddf6d3d..a4668d3 100644
>> --- a/gcc/graphite-clast-to-gimple.c
>> +++ b/gcc/graphite-clast-to-gimple.c
>> @@ -812,6 +812,9 @@ clast_get_body_of_loop (struct clast_stmt *stmt)
>> if (CLAST_STMT_IS_A (stmt, stmt_block))
>> return clast_get_body_of_loop (((struct clast_block *) stmt)->body);
>>
>> + if (CLAST_STMT_IS_A (stmt, stmt_ass))
>> + return clast_get_body_of_loop (stmt->next);
>> +
>> gcc_unreachable ();
>> }
>>
>> @@ -1121,6 +1124,48 @@ translate_clast_for (loop_p context_loop, struct
>> clast_for *stmt, edge next_e,
>> return last_e;
>> }
>>
>> +/* Translates a clast assignment STMT to gimple.
>> +
>> + - NEXT_E is the edge where new generated code should be attached.
>> + - BB_PBB_MAPPING is is a basic_block and it's related poly_bb_p mapping.
>> */
>> +
>> +static edge
>> +translate_clast_assignment (struct clast_assignment *stmt, edge next_e,
>> + int level, ivs_params_p ip)
>> +{
>> + gimple_seq stmts;
>> + mpz_t v1, v2;
>> + tree type, new_name, var;
>> + edge res = single_succ_edge (split_edge (next_e));
>> + struct clast_expr *expr = (struct clast_expr *) stmt->RHS;
>> + struct clast_user_stmt *body
>> + = clast_get_body_of_loop ((struct clast_stmt *) stmt);
>> + poly_bb_p pbb = (poly_bb_p) cloog_statement_usr (body->statement);
>> +
>> + mpz_init (v1);
>> + mpz_init (v2);
>> + type = type_for_clast_expr (expr, ip, v1, v2);
>> + var = create_tmp_var (type, "graphite_var");
>> + new_name = force_gimple_operand (clast_to_gcc_expression (type, expr, ip),
>> + &stmts, true, var);
>> + add_referenced_var (var);
>> + if (stmts)
>> + {
>> + gsi_insert_seq_on_edge (next_e, stmts);
>> + gsi_commit_edge_inserts ();
>> + }
>> +
>> + compute_bounds_for_level (pbb, level, v1, v2);
>> + save_clast_name_index (ip->newivs_index, stmt->LHS,
>> + VEC_length (tree, *(ip->newivs)), level, v1, v2);
>> + VEC_safe_push (tree, heap, *(ip->newivs), new_name);
>> +
>> + mpz_clear (v1);
>> + mpz_clear (v2);
>> +
>> + return res;
>> +}
>> +
>> /* Translates a clast guard statement STMT to gimple.
>>
>> - NEXT_E is the edge where new generated code should be attached.
>> @@ -1171,6 +1216,10 @@ translate_clast (loop_p context_loop, struct
>> clast_stmt *stmt, edge next_e,
>> else if (CLAST_STMT_IS_A (stmt, stmt_block))
>> next_e = translate_clast (context_loop, ((struct clast_block *)
>> stmt)->body,
>> next_e, bb_pbb_mapping, level, ip);
>> +
>> + else if (CLAST_STMT_IS_A (stmt, stmt_ass))
>> + next_e = translate_clast_assignment ((struct clast_assignment *) stmt,
>> + next_e, level, ip);
>> else
>> gcc_unreachable();
>>
>> diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
>> index a63b647..bfdbcfb 100644
>> --- a/gcc/testsuite/ChangeLog
>> +++ b/gcc/testsuite/ChangeLog
>> @@ -1,3 +1,8 @@
>> +2011-07-22 Sebastian Pop <sebastian....@amd.com>
>> +
>> + PR middle-end/48648
>> + * gcc.dg/graphite/id-pr48648.c: New.
>> +
>> 2011-07-21 Sebastian Pop <sebastian....@amd.com>
>>
>> PR middle-end/47654
>> diff --git a/gcc/testsuite/gcc.dg/graphite/id-pr48648.c
>> b/gcc/testsuite/gcc.dg/graphite/id-pr48648.c
>> new file mode 100644
>> index 0000000..ff58ec2
>> --- /dev/null
>> +++ b/gcc/testsuite/gcc.dg/graphite/id-pr48648.c
>> @@ -0,0 +1,21 @@
>> +/* { dg-options "-O -fgraphite-identity" } */
>> +
>> +void *foo(const void *a);
>> +
>> +void bug48648()
>> +{
>> + unsigned char a[2];
>> + long b;
>> + int i;
>> +
>> + for(i = 0; i < 2; i++) {
>> + if (b <= 0)
>> + a[i] = 0;
>> + else if (b >= 8)
>> + a[i] = 0;
>> + else
>> + a[i] = 0;
>> + b -= 8;
>> + }
>> + foo(&a);
>> +}
>> --
>> 1.7.4.1
>>
>>
>
