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tree-ssa-reassoc.c (maybe_optimize_range_tests): Return boolean indicating if a gimple conditional was optimized to true/false.

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* tree-ssa-reassoc.c (maybe_optimize_range_tests): Return boolean
	indicating if a gimple conditional was optimized to true/false.
	(reassociate_bb): Bubble up return value from
	maybe_optimize_range_tests.
	(do_reassoc): Similarly, but for reassociate_bb.
	(execute_reassoc): Return TODO_cleanup_cfg as needed.

	* gcc.dg/tree-ssa/reassoc-43.c: New test.

From-SVN: r231277
This commit is contained in:
Jeff Law 2015-12-04 09:19:30 -07:00 • committed by Jeff Law
parent 7d9425d46b
commit 8010f31fc7
4 changed files with 113 additions and 20 deletions
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9
gcc/ChangeLog
View file

@ -1,3 +1,12 @@
2015-12-04 Jeff Law <law@redhat.com>
* tree-ssa-reassoc.c (maybe_optimize_range_tests): Return boolean
indicating if a gimple conditional was optimized to true/false.
(reassociate_bb): Bubble up return value from
maybe_optimize_range_tests.
(do_reassoc): Similarly, but for reassociate_bb.
(execute_reassoc): Return TODO_cleanup_cfg as needed.
2015-12-04 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
* config/aarch64/aarch64.c (aarch64_override_options_internal):

4
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,7 @@
2015-12-02 Jeff Law <law@redhat.com>
* gcc.dg/tree-ssa/reassoc-43.c: New test.
2015-12-04 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
* gcc.target/aarch64/mgeneral-regs_4.c: New test.

53
gcc/testsuite/gcc.dg/tree-ssa/reassoc-43.c Normal file
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@ -0,0 +1,53 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-reassoc -w" } */
typedef union tree_node *tree;
enum cpp_ttype { CPP_COLON, CPP_SEMICOLON, CPP_CLOSE_BRACE, CPP_COMMA };
enum rid { RID_STATIC = 0, RID_ATTRIBUTE, };
typedef struct c_token
{
enum cpp_ttype type:8;
}
c_token;
typedef struct c_parser
{
c_token tokens[2];
short tokens_avail;
}
c_parser;
__inline__ c_token *
c_parser_peek_token (c_parser * parser)
{
if (parser->tokens_avail == 0)
{
parser->tokens_avail = 1;
}
return &parser->tokens[0];
}
__inline__ unsigned char
c_parser_next_token_is (c_parser * parser, enum cpp_ttype type)
{
return c_parser_peek_token (parser)->type == type;
}
void
c_parser_translation_unit (c_parser * parser)
{
tree prefix_attrs;
tree all_prefix_attrs;
while (1)
{
if (c_parser_next_token_is (parser, CPP_COLON)
|| c_parser_next_token_is (parser, CPP_COMMA)
|| c_parser_next_token_is (parser, CPP_SEMICOLON)
|| c_parser_next_token_is (parser, CPP_CLOSE_BRACE)
|| c_parser_next_token_is_keyword (parser, RID_ATTRIBUTE))
{
if (c_parser_next_token_is_keyword (parser, RID_ATTRIBUTE))
all_prefix_attrs =
chainon (c_parser_attributes (parser), prefix_attrs);
}
}
}
/* { dg-final { scan-tree-dump-not "0 != 0" "reassoc2"} } */

67
gcc/tree-ssa-reassoc.c
View file

@ -2976,9 +2976,15 @@ struct inter_bb_range_test_entry
unsigned int first_idx, last_idx;
};
/* Inter-bb range test optimization. */
/* Inter-bb range test optimization.
static void
Returns TRUE if a gimple conditional is optimized to a true/false,
otherwise return FALSE.
This indicates to the caller that it should run a CFG cleanup pass
once reassociation is completed. */
static bool
maybe_optimize_range_tests (gimple *stmt)
{
basic_block first_bb = gimple_bb (stmt);
@ -2990,6 +2996,7 @@ maybe_optimize_range_tests (gimple *stmt)
auto_vec<operand_entry *> ops;
auto_vec<inter_bb_range_test_entry> bbinfo;
bool any_changes = false;
bool cfg_cleanup_needed = false;
/* Consider only basic blocks that end with GIMPLE_COND or
a cast statement satisfying final_range_test_p. All
@ -2998,15 +3005,15 @@ maybe_optimize_range_tests (gimple *stmt)
if (gimple_code (stmt) == GIMPLE_COND)
{
if (EDGE_COUNT (first_bb->succs) != 2)
return;
return cfg_cleanup_needed;
}
else if (final_range_test_p (stmt))
other_bb = single_succ (first_bb);
else
return;
return cfg_cleanup_needed;
if (stmt_could_throw_p (stmt))
return;
return cfg_cleanup_needed;
/* As relative ordering of post-dominator sons isn't fixed,
maybe_optimize_range_tests can be called first on any
@ -3030,14 +3037,14 @@ maybe_optimize_range_tests (gimple *stmt)
/* As non-GIMPLE_COND last stmt always terminates the range,
if forward search didn't discover anything, just give up. */
if (gimple_code (stmt) != GIMPLE_COND)
return;
return cfg_cleanup_needed;
/* Look at both successors. Either it ends with a GIMPLE_COND
and satisfies suitable_cond_bb, or ends with a cast and
other_bb is that cast's successor. */
FOR_EACH_EDGE (e, ei, first_bb->succs)
if (!(e->flags & (EDGE_TRUE_VALUE | EDGE_FALSE_VALUE))
|| e->dest == first_bb)
return;
return cfg_cleanup_needed;
else if (single_pred_p (e->dest))
{
stmt = last_stmt (e->dest);
@ -3060,7 +3067,7 @@ maybe_optimize_range_tests (gimple *stmt)
}
}
if (other_bb == NULL)
return;
return cfg_cleanup_needed;
}
/* Now do the forward search, moving last_bb to successor bbs
that aren't other_bb. */
@ -3080,7 +3087,7 @@ maybe_optimize_range_tests (gimple *stmt)
last_bb = e->dest;
}
if (first_bb == last_bb)
return;
return cfg_cleanup_needed;
/* Here basic blocks first_bb through last_bb's predecessor
end with GIMPLE_COND, all of them have one of the edges to
other_bb and another to another block in the range,
@ -3289,10 +3296,18 @@ maybe_optimize_range_tests (gimple *stmt)
&& ops[bbinfo[idx].first_idx]->op != NULL_TREE)
{
gcond *cond_stmt = as_a <gcond *> (last_stmt (bb));
/* If we collapse the conditional to a true/false
condition, then bubble that knowledge up to our caller. */
if (integer_zerop (ops[bbinfo[idx].first_idx]->op))
gimple_cond_make_false (cond_stmt);
{
gimple_cond_make_false (cond_stmt);
cfg_cleanup_needed = true;
}
else if (integer_onep (ops[bbinfo[idx].first_idx]->op))
gimple_cond_make_true (cond_stmt);
{
gimple_cond_make_true (cond_stmt);
cfg_cleanup_needed = true;
}
else
{
gimple_cond_set_code (cond_stmt, NE_EXPR);
@ -3306,6 +3321,7 @@ maybe_optimize_range_tests (gimple *stmt)
break;
}
}
return cfg_cleanup_needed;
}
/* Return true if OPERAND is defined by a PHI node which uses the LHS
@ -4753,17 +4769,20 @@ transform_stmt_to_multiply (gimple_stmt_iterator *gsi, gimple *stmt,
}
/* Reassociate expressions in basic block BB and its post-dominator as
children. */
children.
static void
Bubble up return status from maybe_optimize_range_tests. */
static bool
reassociate_bb (basic_block bb)
{
gimple_stmt_iterator gsi;
basic_block son;
gimple *stmt = last_stmt (bb);
bool cfg_cleanup_needed = false;
if (stmt && !gimple_visited_p (stmt))
maybe_optimize_range_tests (stmt);
cfg_cleanup_needed |= maybe_optimize_range_tests (stmt);
for (gsi = gsi_last_bb (bb); !gsi_end_p (gsi); gsi_prev (&gsi))
{
@ -4922,7 +4941,9 @@ reassociate_bb (basic_block bb)
for (son = first_dom_son (CDI_POST_DOMINATORS, bb);
son;
son = next_dom_son (CDI_POST_DOMINATORS, son))
reassociate_bb (son);
cfg_cleanup_needed |= reassociate_bb (son);
return cfg_cleanup_needed;
}
/* Add jumps around shifts for range tests turned into bit tests.
@ -5028,11 +5049,13 @@ debug_ops_vector (vec<operand_entry *> ops)
dump_ops_vector (stderr, ops);
}
static void
/* Bubble up return status from reassociate_bb. */
static bool
do_reassoc (void)
{
break_up_subtract_bb (ENTRY_BLOCK_PTR_FOR_FN (cfun));
reassociate_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
return reassociate_bb (EXIT_BLOCK_PTR_FOR_FN (cfun));
}
/* Initialize the reassociation pass. */
@ -5106,7 +5129,10 @@ fini_reassoc (void)
}
/* Gate and execute functions for Reassociation. If INSERT_POWI_P, enable
insertion of __builtin_powi calls. */
insertion of __builtin_powi calls.
Returns TODO_cfg_cleanup if a CFG cleanup pass is desired due to
optimization of a gimple conditional. Otherwise returns zero. */
static unsigned int
execute_reassoc (bool insert_powi_p)
@ -5115,12 +5141,13 @@ execute_reassoc (bool insert_powi_p)
init_reassoc ();
do_reassoc ();
bool cfg_cleanup_needed;
cfg_cleanup_needed = do_reassoc ();
repropagate_negates ();
branch_fixup ();
fini_reassoc ();
return 0;
return cfg_cleanup_needed ? TODO_cleanup_cfg : 0;
}
namespace {