1 /* Gimple range GORI functions.
2 Copyright (C) 2017-2023 Free Software Foundation, Inc.
3 Contributed by Andrew MacLeod <amacleod@redhat.com>
4 and Aldy Hernandez <aldyh@redhat.com>.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
29 #include "gimple-pretty-print.h"
30 #include "gimple-range.h"
32 // Return TRUE if GS is a logical && or || expression.
35 is_gimple_logical_p (const gimple
*gs
)
37 // Look for boolean and/or condition.
38 if (is_gimple_assign (gs
))
39 switch (gimple_expr_code (gs
))
47 // Bitwise operations on single bits are logical too.
48 if (types_compatible_p (TREE_TYPE (gimple_assign_rhs1 (gs
)),
59 /* RANGE_DEF_CHAIN is used to determine which SSA names in a block can
60 have range information calculated for them, and what the
61 dependencies on each other are.
63 Information for a basic block is calculated once and stored. It is
64 only calculated the first time a query is made, so if no queries
65 are made, there is little overhead.
67 The def_chain bitmap is indexed by SSA_NAME_VERSION. Bits are set
68 within this bitmap to indicate SSA names that are defined in the
69 SAME block and used to calculate this SSA name.
83 This dump indicates the bits set in the def_chain vector.
84 as well as demonstrates the def_chain bits for the related ssa_names.
86 Checking the chain for _2 indicates that _1 and x_4 are used in
89 Def chains also only include statements which are valid gimple
90 so a def chain will only span statements for which the range
91 engine implements operations for. */
94 // Construct a range_def_chain.
96 range_def_chain::range_def_chain ()
98 bitmap_obstack_initialize (&m_bitmaps
);
99 m_def_chain
.create (0);
100 m_def_chain
.safe_grow_cleared (num_ssa_names
);
104 // Destruct a range_def_chain.
106 range_def_chain::~range_def_chain ()
108 m_def_chain
.release ();
109 bitmap_obstack_release (&m_bitmaps
);
112 // Return true if NAME is in the def chain of DEF. If BB is provided,
113 // only return true if the defining statement of DEF is in BB.
116 range_def_chain::in_chain_p (tree name
, tree def
)
118 gcc_checking_assert (gimple_range_ssa_p (def
));
119 gcc_checking_assert (gimple_range_ssa_p (name
));
121 // Get the definition chain for DEF.
122 bitmap chain
= get_def_chain (def
);
126 return bitmap_bit_p (chain
, SSA_NAME_VERSION (name
));
129 // Add either IMP or the import list B to the import set of DATA.
132 range_def_chain::set_import (struct rdc
&data
, tree imp
, bitmap b
)
134 // If there are no imports, just return
135 if (imp
== NULL_TREE
&& !b
)
138 data
.m_import
= BITMAP_ALLOC (&m_bitmaps
);
139 if (imp
!= NULL_TREE
)
140 bitmap_set_bit (data
.m_import
, SSA_NAME_VERSION (imp
));
142 bitmap_ior_into (data
.m_import
, b
);
145 // Return the import list for NAME.
148 range_def_chain::get_imports (tree name
)
150 if (!has_def_chain (name
))
151 get_def_chain (name
);
152 bitmap i
= m_def_chain
[SSA_NAME_VERSION (name
)].m_import
;
156 // Return true if IMPORT is an import to NAMEs def chain.
159 range_def_chain::chain_import_p (tree name
, tree import
)
161 bitmap b
= get_imports (name
);
163 return bitmap_bit_p (b
, SSA_NAME_VERSION (import
));
167 // Build def_chains for NAME if it is in BB. Copy the def chain into RESULT.
170 range_def_chain::register_dependency (tree name
, tree dep
, basic_block bb
)
172 if (!gimple_range_ssa_p (dep
))
175 unsigned v
= SSA_NAME_VERSION (name
);
176 if (v
>= m_def_chain
.length ())
177 m_def_chain
.safe_grow_cleared (num_ssa_names
+ 1);
178 struct rdc
&src
= m_def_chain
[v
];
179 gimple
*def_stmt
= SSA_NAME_DEF_STMT (dep
);
180 unsigned dep_v
= SSA_NAME_VERSION (dep
);
183 // Set the direct dependency cache entries.
185 src
.ssa1
= SSA_NAME_VERSION (dep
);
186 else if (!src
.ssa2
&& src
.ssa1
!= SSA_NAME_VERSION (dep
))
187 src
.ssa2
= SSA_NAME_VERSION (dep
);
189 // Don't calculate imports or export/dep chains if BB is not provided.
190 // This is usually the case for when the temporal cache wants the direct
191 // dependencies of a stmt.
196 src
.bm
= BITMAP_ALLOC (&m_bitmaps
);
198 // Add this operand into the result.
199 bitmap_set_bit (src
.bm
, dep_v
);
201 if (gimple_bb (def_stmt
) == bb
&& !is_a
<gphi
*>(def_stmt
))
203 // Get the def chain for the operand.
204 b
= get_def_chain (dep
);
205 // If there was one, copy it into result. Access def_chain directly
206 // as the get_def_chain request above could reallocate the vector.
208 bitmap_ior_into (m_def_chain
[v
].bm
, b
);
209 // And copy the import list.
210 set_import (m_def_chain
[v
], NULL_TREE
, get_imports (dep
));
213 // Originated outside the block, so it is an import.
214 set_import (src
, dep
, NULL
);
218 range_def_chain::def_chain_in_bitmap_p (tree name
, bitmap b
)
220 bitmap a
= get_def_chain (name
);
222 return bitmap_intersect_p (a
, b
);
227 range_def_chain::add_def_chain_to_bitmap (bitmap b
, tree name
)
229 bitmap r
= get_def_chain (name
);
231 bitmap_ior_into (b
, r
);
235 // Return TRUE if NAME has been processed for a def_chain.
238 range_def_chain::has_def_chain (tree name
)
240 // Ensure there is an entry in the internal vector.
241 unsigned v
= SSA_NAME_VERSION (name
);
242 if (v
>= m_def_chain
.length ())
243 m_def_chain
.safe_grow_cleared (num_ssa_names
+ 1);
244 return (m_def_chain
[v
].ssa1
!= 0);
249 // Calculate the def chain for NAME and all of its dependent
250 // operands. Only using names in the same BB. Return the bitmap of
251 // all names in the m_def_chain. This only works for supported range
255 range_def_chain::get_def_chain (tree name
)
258 unsigned v
= SSA_NAME_VERSION (name
);
260 // If it has already been processed, just return the cached value.
261 if (has_def_chain (name
) && m_def_chain
[v
].bm
)
262 return m_def_chain
[v
].bm
;
264 // No definition chain for default defs.
265 if (SSA_NAME_IS_DEFAULT_DEF (name
))
267 // A Default def is always an import.
268 set_import (m_def_chain
[v
], name
, NULL
);
272 gimple
*stmt
= SSA_NAME_DEF_STMT (name
);
273 unsigned count
= gimple_range_ssa_names (ssa
, 3, stmt
);
276 // Stmts not understood or with no operands are always imports.
277 set_import (m_def_chain
[v
], name
, NULL
);
281 // Terminate the def chains if we see too many cascading stmts.
282 if (m_logical_depth
== param_ranger_logical_depth
)
285 // Increase the depth if we have a pair of ssa-names.
289 for (unsigned x
= 0; x
< count
; x
++)
290 register_dependency (name
, ssa
[x
], gimple_bb (stmt
));
295 return m_def_chain
[v
].bm
;
298 // Dump what we know for basic block BB to file F.
301 range_def_chain::dump (FILE *f
, basic_block bb
, const char *prefix
)
306 // Dump the def chain for each SSA_NAME defined in BB.
307 for (x
= 1; x
< num_ssa_names
; x
++)
309 tree name
= ssa_name (x
);
312 gimple
*stmt
= SSA_NAME_DEF_STMT (name
);
313 if (!stmt
|| (bb
&& gimple_bb (stmt
) != bb
))
315 bitmap chain
= (has_def_chain (name
) ? get_def_chain (name
) : NULL
);
316 if (chain
&& !bitmap_empty_p (chain
))
319 print_generic_expr (f
, name
, TDF_SLIM
);
322 bitmap imports
= get_imports (name
);
323 EXECUTE_IF_SET_IN_BITMAP (chain
, 0, y
, bi
)
325 print_generic_expr (f
, ssa_name (y
), TDF_SLIM
);
326 if (imports
&& bitmap_bit_p (imports
, y
))
336 // -------------------------------------------------------------------
338 /* GORI_MAP is used to accumulate what SSA names in a block can
339 generate range information, and provides tools for the block ranger
340 to enable it to efficiently calculate these ranges.
342 GORI stands for "Generates Outgoing Range Information."
344 It utilizes the range_def_chain class to construct def_chains.
345 Information for a basic block is calculated once and stored. It is
346 only calculated the first time a query is made. If no queries are
347 made, there is little overhead.
349 one bitmap is maintained for each basic block:
350 m_outgoing : a set bit indicates a range can be generated for a name.
352 Generally speaking, the m_outgoing vector is the union of the
353 entire def_chain of all SSA names used in the last statement of the
354 block which generate ranges. */
357 // Initialize a gori-map structure.
359 gori_map::gori_map ()
361 m_outgoing
.create (0);
362 m_outgoing
.safe_grow_cleared (last_basic_block_for_fn (cfun
));
363 m_incoming
.create (0);
364 m_incoming
.safe_grow_cleared (last_basic_block_for_fn (cfun
));
365 m_maybe_variant
= BITMAP_ALLOC (&m_bitmaps
);
368 // Free any memory the GORI map allocated.
370 gori_map::~gori_map ()
372 m_incoming
.release ();
373 m_outgoing
.release ();
376 // Return the bitmap vector of all export from BB. Calculate if necessary.
379 gori_map::exports (basic_block bb
)
381 if (bb
->index
>= (signed int)m_outgoing
.length () || !m_outgoing
[bb
->index
])
383 return m_outgoing
[bb
->index
];
386 // Return the bitmap vector of all imports to BB. Calculate if necessary.
389 gori_map::imports (basic_block bb
)
391 if (bb
->index
>= (signed int)m_outgoing
.length () || !m_outgoing
[bb
->index
])
393 return m_incoming
[bb
->index
];
396 // Return true if NAME is can have ranges generated for it from basic
400 gori_map::is_export_p (tree name
, basic_block bb
)
402 // If no BB is specified, test if it is exported anywhere in the IL.
404 return bitmap_bit_p (m_maybe_variant
, SSA_NAME_VERSION (name
));
405 return bitmap_bit_p (exports (bb
), SSA_NAME_VERSION (name
));
408 // Set or clear the m_maybe_variant bit to determine if ranges will be tracked
409 // for NAME. A clear bit means they will NOT be tracked.
412 gori_map::set_range_invariant (tree name
, bool invariant
)
415 bitmap_clear_bit (m_maybe_variant
, SSA_NAME_VERSION (name
));
417 bitmap_set_bit (m_maybe_variant
, SSA_NAME_VERSION (name
));
420 // Return true if NAME is an import to block BB.
423 gori_map::is_import_p (tree name
, basic_block bb
)
425 // If no BB is specified, test if it is exported anywhere in the IL.
426 return bitmap_bit_p (imports (bb
), SSA_NAME_VERSION (name
));
429 // If NAME is non-NULL and defined in block BB, calculate the def
430 // chain and add it to m_outgoing.
433 gori_map::maybe_add_gori (tree name
, basic_block bb
)
437 // Check if there is a def chain, regardless of the block.
438 add_def_chain_to_bitmap (m_outgoing
[bb
->index
], name
);
439 // Check for any imports.
440 bitmap imp
= get_imports (name
);
441 // If there were imports, add them so we can recompute
443 bitmap_ior_into (m_incoming
[bb
->index
], imp
);
444 // This name is always an import.
445 if (gimple_bb (SSA_NAME_DEF_STMT (name
)) != bb
)
446 bitmap_set_bit (m_incoming
[bb
->index
], SSA_NAME_VERSION (name
));
448 // Def chain doesn't include itself, and even if there isn't a
449 // def chain, this name should be added to exports.
450 bitmap_set_bit (m_outgoing
[bb
->index
], SSA_NAME_VERSION (name
));
454 // Calculate all the required information for BB.
457 gori_map::calculate_gori (basic_block bb
)
460 if (bb
->index
>= (signed int)m_outgoing
.length ())
462 m_outgoing
.safe_grow_cleared (last_basic_block_for_fn (cfun
));
463 m_incoming
.safe_grow_cleared (last_basic_block_for_fn (cfun
));
465 gcc_checking_assert (m_outgoing
[bb
->index
] == NULL
);
466 m_outgoing
[bb
->index
] = BITMAP_ALLOC (&m_bitmaps
);
467 m_incoming
[bb
->index
] = BITMAP_ALLOC (&m_bitmaps
);
469 if (single_succ_p (bb
))
472 // If this block's last statement may generate range information, go
474 gimple
*stmt
= gimple_outgoing_range_stmt_p (bb
);
477 if (is_a
<gcond
*> (stmt
))
479 gcond
*gc
= as_a
<gcond
*>(stmt
);
480 name
= gimple_range_ssa_p (gimple_cond_lhs (gc
));
481 maybe_add_gori (name
, gimple_bb (stmt
));
483 name
= gimple_range_ssa_p (gimple_cond_rhs (gc
));
484 maybe_add_gori (name
, gimple_bb (stmt
));
488 // Do not process switches if they are too large.
489 if (EDGE_COUNT (bb
->succs
) > (unsigned)param_vrp_switch_limit
)
491 gswitch
*gs
= as_a
<gswitch
*>(stmt
);
492 name
= gimple_range_ssa_p (gimple_switch_index (gs
));
493 maybe_add_gori (name
, gimple_bb (stmt
));
495 // Add this bitmap to the aggregate list of all outgoing names.
496 bitmap_ior_into (m_maybe_variant
, m_outgoing
[bb
->index
]);
499 // Dump the table information for BB to file F.
502 gori_map::dump (FILE *f
, basic_block bb
, bool verbose
)
504 // BB was not processed.
505 if (!m_outgoing
[bb
->index
] || bitmap_empty_p (m_outgoing
[bb
->index
]))
510 bitmap imp
= imports (bb
);
511 if (!bitmap_empty_p (imp
))
514 fprintf (f
, "bb<%u> Imports: ",bb
->index
);
516 fprintf (f
, "Imports: ");
517 FOR_EACH_GORI_IMPORT_NAME (*this, bb
, name
)
519 print_generic_expr (f
, name
, TDF_SLIM
);
526 fprintf (f
, "bb<%u> Exports: ",bb
->index
);
528 fprintf (f
, "Exports: ");
529 // Dump the export vector.
530 FOR_EACH_GORI_EXPORT_NAME (*this, bb
, name
)
532 print_generic_expr (f
, name
, TDF_SLIM
);
537 range_def_chain::dump (f
, bb
, " ");
540 // Dump the entire GORI map structure to file F.
543 gori_map::dump (FILE *f
)
546 FOR_EACH_BB_FN (bb
, cfun
)
556 // -------------------------------------------------------------------
558 // Construct a gori_compute object.
560 gori_compute::gori_compute (int not_executable_flag
)
561 : outgoing (param_vrp_switch_limit
), tracer ("GORI ")
563 m_not_executable_flag
= not_executable_flag
;
564 // Create a boolean_type true and false range.
565 m_bool_zero
= range_false ();
566 m_bool_one
= range_true ();
567 if (dump_file
&& (param_ranger_debug
& RANGER_DEBUG_GORI
))
568 tracer
.enable_trace ();
571 // Given the switch S, return an evaluation in R for NAME when the lhs
572 // evaluates to LHS. Returning false means the name being looked for
573 // was not resolvable.
576 gori_compute::compute_operand_range_switch (vrange
&r
, gswitch
*s
,
578 tree name
, fur_source
&src
)
580 tree op1
= gimple_switch_index (s
);
582 // If name matches, the range is simply the range from the edge.
583 // Empty ranges are viral as they are on a path which isn't
585 if (op1
== name
|| lhs
.undefined_p ())
591 // If op1 is in the definition chain, pass lhs back.
592 if (gimple_range_ssa_p (op1
) && in_chain_p (name
, op1
))
593 return compute_operand_range (r
, SSA_NAME_DEF_STMT (op1
), lhs
, name
, src
);
599 // Return an evaluation for NAME as it would appear in STMT when the
600 // statement's lhs evaluates to LHS. If successful, return TRUE and
601 // store the evaluation in R, otherwise return FALSE.
604 gori_compute::compute_operand_range (vrange
&r
, gimple
*stmt
,
605 const vrange
&lhs
, tree name
,
606 fur_source
&src
, value_relation
*rel
)
609 value_relation
*vrel_ptr
= rel
;
610 // Empty ranges are viral as they are on an unexecutable path.
611 if (lhs
.undefined_p ())
616 if (is_a
<gswitch
*> (stmt
))
617 return compute_operand_range_switch (r
, as_a
<gswitch
*> (stmt
), lhs
, name
,
619 gimple_range_op_handler
handler (stmt
);
623 tree op1
= gimple_range_ssa_p (handler
.operand1 ());
624 tree op2
= gimple_range_ssa_p (handler
.operand2 ());
626 // If there is a relation betwen op1 and op2, use it instead as it is
627 // likely to be more applicable.
631 r1
.set_varying (TREE_TYPE (op1
));
632 r2
.set_varying (TREE_TYPE (op2
));
633 relation_kind k
= handler
.op1_op2_relation (lhs
, r1
, r2
);
634 if (k
!= VREL_VARYING
)
636 vrel
.set_relation (k
, op1
, op2
);
641 // Handle end of lookup first.
643 return compute_operand1_range (r
, handler
, lhs
, src
, vrel_ptr
);
645 return compute_operand2_range (r
, handler
, lhs
, src
, vrel_ptr
);
647 // NAME is not in this stmt, but one of the names in it ought to be
649 bool op1_in_chain
= op1
&& in_chain_p (name
, op1
);
650 bool op2_in_chain
= op2
&& in_chain_p (name
, op2
);
652 // If neither operand is derived, then this stmt tells us nothing.
653 if (!op1_in_chain
&& !op2_in_chain
)
656 // If either operand is in the def chain of the other (or they are equal), it
657 // will be evaluated twice and can result in an exponential time calculation.
658 // Instead just evaluate the one operand.
659 if (op1_in_chain
&& op2_in_chain
)
661 if (in_chain_p (op1
, op2
) || op1
== op2
)
662 op1_in_chain
= false;
663 else if (in_chain_p (op2
, op1
))
664 op2_in_chain
= false;
668 // If the lhs doesn't tell us anything only a relation can possibly enhance
670 if (lhs
.varying_p ())
674 // If there is a relation (ie: x != y) , it can only be relevant if
675 // a) both elements are in the defchain
676 // c = x > y // (x and y are in c's defchain)
678 res
= in_chain_p (vrel_ptr
->op1 (), op1
)
679 && in_chain_p (vrel_ptr
->op2 (), op1
);
680 if (!res
&& op2_in_chain
)
681 res
= in_chain_p (vrel_ptr
->op1 (), op2
)
682 || in_chain_p (vrel_ptr
->op2 (), op2
);
685 // or b) one relation element is in the defchain of the other and the
686 // other is the LHS of this stmt.
688 if (vrel_ptr
->op1 () == handler
.lhs ()
689 && (vrel_ptr
->op2 () == op1
|| vrel_ptr
->op2 () == op2
))
691 else if (vrel_ptr
->op2 () == handler
.lhs ()
692 && (vrel_ptr
->op1 () == op1
|| vrel_ptr
->op1 () == op2
))
699 // Process logicals as they have special handling.
700 if (is_gimple_logical_p (stmt
))
702 // If the lhs doesn't tell us anything, neither will combining operands.
703 if (lhs
.varying_p ())
707 if ((idx
= tracer
.header ("compute_operand ")))
709 print_generic_expr (dump_file
, name
, TDF_SLIM
);
710 fprintf (dump_file
, " with LHS = ");
711 lhs
.dump (dump_file
);
712 fprintf (dump_file
, " at stmt ");
713 print_gimple_stmt (dump_file
, stmt
, 0, TDF_SLIM
);
716 tree type
= TREE_TYPE (name
);
717 Value_Range
op1_trange (type
), op1_frange (type
);
718 Value_Range
op2_trange (type
), op2_frange (type
);
719 compute_logical_operands (op1_trange
, op1_frange
, handler
,
721 name
, src
, op1
, op1_in_chain
);
722 compute_logical_operands (op2_trange
, op2_frange
, handler
,
724 name
, src
, op2
, op2_in_chain
);
725 res
= logical_combine (r
,
726 gimple_expr_code (stmt
),
728 op1_trange
, op1_frange
, op2_trange
, op2_frange
);
730 tracer
.trailer (idx
, "compute_operand", res
, name
, r
);
733 // Follow the appropriate operands now.
734 if (op1_in_chain
&& op2_in_chain
)
735 return compute_operand1_and_operand2_range (r
, handler
, lhs
, name
, src
,
741 vr
.set_type (TREE_TYPE (op1
));
742 if (!compute_operand1_range (vr
, handler
, lhs
, src
, vrel_ptr
))
744 src_stmt
= SSA_NAME_DEF_STMT (op1
);
748 gcc_checking_assert (op2_in_chain
);
749 vr
.set_type (TREE_TYPE (op2
));
750 if (!compute_operand2_range (vr
, handler
, lhs
, src
, vrel_ptr
))
752 src_stmt
= SSA_NAME_DEF_STMT (op2
);
755 gcc_checking_assert (src_stmt
);
756 // Then feed this range back as the LHS of the defining statement.
757 return compute_operand_range (r
, src_stmt
, vr
, name
, src
, vrel_ptr
);
758 // If neither operand is derived, this statement tells us nothing.
762 // Return TRUE if range R is either a true or false compatible range.
765 range_is_either_true_or_false (const irange
&r
)
767 if (r
.undefined_p ())
770 // This is complicated by the fact that Ada has multi-bit booleans,
771 // so true can be ~[0, 0] (i.e. [1,MAX]).
772 tree type
= r
.type ();
773 gcc_checking_assert (range_compatible_p (type
, boolean_type_node
));
774 return (r
.singleton_p ()
775 || !r
.contains_p (wi::zero (TYPE_PRECISION (type
))));
778 // Evaluate a binary logical expression by combining the true and
779 // false ranges for each of the operands based on the result value in
783 gori_compute::logical_combine (vrange
&r
, enum tree_code code
,
785 const vrange
&op1_true
, const vrange
&op1_false
,
786 const vrange
&op2_true
, const vrange
&op2_false
)
788 if (op1_true
.varying_p () && op1_false
.varying_p ()
789 && op2_true
.varying_p () && op2_false
.varying_p ())
793 if ((idx
= tracer
.header ("logical_combine")))
799 fprintf (dump_file
, " || ");
803 fprintf (dump_file
, " && ");
808 fprintf (dump_file
, " with LHS = ");
809 lhs
.dump (dump_file
);
810 fputc ('\n', dump_file
);
812 tracer
.print (idx
, "op1_true = ");
813 op1_true
.dump (dump_file
);
814 fprintf (dump_file
, " op1_false = ");
815 op1_false
.dump (dump_file
);
816 fputc ('\n', dump_file
);
817 tracer
.print (idx
, "op2_true = ");
818 op2_true
.dump (dump_file
);
819 fprintf (dump_file
, " op2_false = ");
820 op2_false
.dump (dump_file
);
821 fputc ('\n', dump_file
);
824 // This is not a simple fold of a logical expression, rather it
825 // determines ranges which flow through the logical expression.
827 // Assuming x_8 is an unsigned char, and relational statements:
830 // consider the logical expression and branch:
834 // To determine the range of x_8 on either edge of the branch, one
835 // must first determine what the range of x_8 is when the boolean
836 // values of b_1 and b_2 are both true and false.
837 // b_1 TRUE x_8 = [0, 19]
838 // b_1 FALSE x_8 = [20, 255]
839 // b_2 TRUE x_8 = [6, 255]
840 // b_2 FALSE x_8 = [0,5].
842 // These ranges are then combined based on the expected outcome of
843 // the branch. The range on the TRUE side of the branch must satisfy
844 // b_1 == true && b_2 == true
846 // In terms of x_8, that means both x_8 == [0, 19] and x_8 = [6, 255]
847 // must be true. The range of x_8 on the true side must be the
848 // intersection of both ranges since both must be true. Thus the
849 // range of x_8 on the true side is [6, 19].
851 // To determine the ranges on the FALSE side, all 3 combinations of
852 // failing ranges must be considered, and combined as any of them
853 // can cause the false result.
855 // If the LHS can be TRUE or FALSE, then evaluate both a TRUE and
856 // FALSE results and combine them. If we fell back to VARYING any
857 // range restrictions that have been discovered up to this point
859 if (!range_is_either_true_or_false (lhs
))
863 if (logical_combine (r1
, code
, m_bool_zero
, op1_true
, op1_false
,
865 && logical_combine (r
, code
, m_bool_one
, op1_true
, op1_false
,
866 op2_true
, op2_false
))
875 tracer
.print (idx
, "logical_combine produced ");
877 fputc ('\n', dump_file
);
884 // A logical AND combines ranges from 2 boolean conditions.
890 // The TRUE side is the intersection of the 2 true ranges.
892 r
.intersect (op2_true
);
896 // The FALSE side is the union of the other 3 cases.
897 Value_Range
ff (op1_false
);
898 ff
.intersect (op2_false
);
899 Value_Range
tf (op1_true
);
900 tf
.intersect (op2_false
);
901 Value_Range
ft (op1_false
);
902 ft
.intersect (op2_true
);
908 // A logical OR combines ranges from 2 boolean conditions.
914 // An OR operation will only take the FALSE path if both
915 // operands are false simultaneously, which means they should
916 // be intersected. !(x || y) == !x && !y
918 r
.intersect (op2_false
);
922 // The TRUE side of an OR operation will be the union of
923 // the other three combinations.
924 Value_Range
tt (op1_true
);
925 tt
.intersect (op2_true
);
926 Value_Range
tf (op1_true
);
927 tf
.intersect (op2_false
);
928 Value_Range
ft (op1_false
);
929 ft
.intersect (op2_true
);
940 tracer
.trailer (idx
, "logical_combine", true, NULL_TREE
, r
);
945 // Given a logical STMT, calculate true and false ranges for each
946 // potential path of NAME, assuming NAME came through the OP chain if
947 // OP_IN_CHAIN is true.
950 gori_compute::compute_logical_operands (vrange
&true_range
, vrange
&false_range
,
951 gimple_range_op_handler
&handler
,
953 tree name
, fur_source
&src
,
954 tree op
, bool op_in_chain
)
956 gimple
*stmt
= handler
.stmt ();
957 gimple
*src_stmt
= gimple_range_ssa_p (op
) ? SSA_NAME_DEF_STMT (op
) : NULL
;
958 if (!op_in_chain
|| !src_stmt
|| chain_import_p (handler
.lhs (), op
))
960 // If op is not in the def chain, or defined in this block,
961 // use its known value on entry to the block.
962 src
.get_operand (true_range
, name
);
963 false_range
= true_range
;
965 if ((idx
= tracer
.header ("logical_operand")))
967 print_generic_expr (dump_file
, op
, TDF_SLIM
);
968 fprintf (dump_file
, " not in computation chain. Queried.\n");
969 tracer
.trailer (idx
, "logical_operand", true, NULL_TREE
, true_range
);
974 enum tree_code code
= gimple_expr_code (stmt
);
975 // Optimize [0 = x | y], since neither operand can ever be non-zero.
976 if ((code
== BIT_IOR_EXPR
|| code
== TRUTH_OR_EXPR
) && lhs
.zero_p ())
978 if (!compute_operand_range (false_range
, src_stmt
, m_bool_zero
, name
,
980 src
.get_operand (false_range
, name
);
981 true_range
= false_range
;
985 // Optimize [1 = x & y], since neither operand can ever be zero.
986 if ((code
== BIT_AND_EXPR
|| code
== TRUTH_AND_EXPR
) && lhs
== m_bool_one
)
988 if (!compute_operand_range (true_range
, src_stmt
, m_bool_one
, name
, src
))
989 src
.get_operand (true_range
, name
);
990 false_range
= true_range
;
994 // Calculate ranges for true and false on both sides, since the false
995 // path is not always a simple inversion of the true side.
996 if (!compute_operand_range (true_range
, src_stmt
, m_bool_one
, name
, src
))
997 src
.get_operand (true_range
, name
);
998 if (!compute_operand_range (false_range
, src_stmt
, m_bool_zero
, name
, src
))
999 src
.get_operand (false_range
, name
);
1003 // This routine will try to refine the ranges of OP1 and OP2 given a relation
1004 // K between them. In order to perform this refinement, one of the operands
1005 // must be in the definition chain of the other. The use is refined using
1006 // op1/op2_range on the statement, and the definition is then recalculated
1007 // using the relation.
1010 gori_compute::refine_using_relation (tree op1
, vrange
&op1_range
,
1011 tree op2
, vrange
&op2_range
,
1012 fur_source
&src
, relation_kind k
)
1014 gcc_checking_assert (TREE_CODE (op1
) == SSA_NAME
);
1015 gcc_checking_assert (TREE_CODE (op2
) == SSA_NAME
);
1017 if (k
== VREL_VARYING
|| k
== VREL_EQ
|| k
== VREL_UNDEFINED
)
1020 bool change
= false;
1021 bool op1_def_p
= in_chain_p (op2
, op1
);
1023 if (!in_chain_p (op1
, op2
))
1026 tree def_op
= op1_def_p
? op1
: op2
;
1027 tree use_op
= op1_def_p
? op2
: op1
;
1030 k
= relation_swap (k
);
1032 // op1_def is true if we want to look up op1, otherwise we want op2.
1033 // if neither is the case, we returned in the above check.
1035 gimple
*def_stmt
= SSA_NAME_DEF_STMT (def_op
);
1036 gimple_range_op_handler
op_handler (def_stmt
);
1039 tree def_op1
= op_handler
.operand1 ();
1040 tree def_op2
= op_handler
.operand2 ();
1041 // if the def isn't binary, the relation will not be useful.
1045 // Determine if op2 is directly referenced as an operand.
1046 if (def_op1
== use_op
)
1048 // def_stmt has op1 in the 1st operand position.
1049 Value_Range
other_op (TREE_TYPE (def_op2
));
1050 src
.get_operand (other_op
, def_op2
);
1052 // Using op1_range as the LHS, and relation REL, evaluate op2.
1053 tree type
= TREE_TYPE (def_op1
);
1054 Value_Range
new_result (type
);
1055 if (!op_handler
.op1_range (new_result
, type
,
1056 op1_def_p
? op1_range
: op2_range
,
1057 other_op
, relation_trio::lhs_op1 (k
)))
1061 change
|= op2_range
.intersect (new_result
);
1063 if (op_handler
.fold_range (new_result
, type
, op2_range
, other_op
))
1065 change
|= op1_range
.intersect (new_result
);
1070 change
|= op1_range
.intersect (new_result
);
1072 if (op_handler
.fold_range (new_result
, type
, op1_range
, other_op
))
1074 change
|= op2_range
.intersect (new_result
);
1078 else if (def_op2
== use_op
)
1080 // def_stmt has op1 in the 1st operand position.
1081 Value_Range
other_op (TREE_TYPE (def_op1
));
1082 src
.get_operand (other_op
, def_op1
);
1084 // Using op1_range as the LHS, and relation REL, evaluate op2.
1085 tree type
= TREE_TYPE (def_op2
);
1086 Value_Range
new_result (type
);
1087 if (!op_handler
.op2_range (new_result
, type
,
1088 op1_def_p
? op1_range
: op2_range
,
1089 other_op
, relation_trio::lhs_op2 (k
)))
1093 change
|= op2_range
.intersect (new_result
);
1095 if (op_handler
.fold_range (new_result
, type
, other_op
, op2_range
))
1097 change
|= op1_range
.intersect (new_result
);
1102 change
|= op1_range
.intersect (new_result
);
1104 if (op_handler
.fold_range (new_result
, type
, other_op
, op1_range
))
1106 change
|= op2_range
.intersect (new_result
);
1113 // Calculate a range for NAME from the operand 1 position of STMT
1114 // assuming the result of the statement is LHS. Return the range in
1115 // R, or false if no range could be calculated.
1118 gori_compute::compute_operand1_range (vrange
&r
,
1119 gimple_range_op_handler
&handler
,
1121 fur_source
&src
, value_relation
*rel
)
1123 gimple
*stmt
= handler
.stmt ();
1124 tree op1
= handler
.operand1 ();
1125 tree op2
= handler
.operand2 ();
1126 tree lhs_name
= gimple_get_lhs (stmt
);
1130 trio
= rel
->create_trio (lhs_name
, op1
, op2
);
1132 Value_Range
op1_range (TREE_TYPE (op1
));
1133 Value_Range
op2_range (op2
? TREE_TYPE (op2
) : TREE_TYPE (op1
));
1135 // Fetch the known range for op1 in this block.
1136 src
.get_operand (op1_range
, op1
);
1138 // Now range-op calculate and put that result in r.
1141 src
.get_operand (op2_range
, op2
);
1143 relation_kind op_op
= trio
.op1_op2 ();
1144 if (op_op
!= VREL_VARYING
)
1145 refine_using_relation (op1
, op1_range
, op2
, op2_range
, src
, op_op
);
1147 // If op1 == op2, create a new trio for just this call.
1148 if (op1
== op2
&& gimple_range_ssa_p (op1
))
1150 relation_kind k
= get_identity_relation (op1
, op1_range
);
1151 trio
= relation_trio (trio
.lhs_op1 (), trio
.lhs_op2 (), k
);
1153 if (!handler
.calc_op1 (r
, lhs
, op2_range
, trio
))
1158 // We pass op1_range to the unary operation. Normally it's a
1159 // hidden range_for_type parameter, but sometimes having the
1160 // actual range can result in better information.
1161 if (!handler
.calc_op1 (r
, lhs
, op1_range
, trio
))
1166 if ((idx
= tracer
.header ("compute op 1 (")))
1168 print_generic_expr (dump_file
, op1
, TDF_SLIM
);
1169 fprintf (dump_file
, ") at ");
1170 print_gimple_stmt (dump_file
, stmt
, 0, TDF_SLIM
);
1171 tracer
.print (idx
, "LHS =");
1172 lhs
.dump (dump_file
);
1173 if (op2
&& TREE_CODE (op2
) == SSA_NAME
)
1175 fprintf (dump_file
, ", ");
1176 print_generic_expr (dump_file
, op2
, TDF_SLIM
);
1177 fprintf (dump_file
, " = ");
1178 op2_range
.dump (dump_file
);
1180 fprintf (dump_file
, "\n");
1181 tracer
.print (idx
, "Computes ");
1182 print_generic_expr (dump_file
, op1
, TDF_SLIM
);
1183 fprintf (dump_file
, " = ");
1185 fprintf (dump_file
, " intersect Known range : ");
1186 op1_range
.dump (dump_file
);
1187 fputc ('\n', dump_file
);
1190 r
.intersect (op1_range
);
1192 tracer
.trailer (idx
, "produces ", true, op1
, r
);
1197 // Calculate a range for NAME from the operand 2 position of S
1198 // assuming the result of the statement is LHS. Return the range in
1199 // R, or false if no range could be calculated.
1202 gori_compute::compute_operand2_range (vrange
&r
,
1203 gimple_range_op_handler
&handler
,
1205 fur_source
&src
, value_relation
*rel
)
1207 gimple
*stmt
= handler
.stmt ();
1208 tree op1
= handler
.operand1 ();
1209 tree op2
= handler
.operand2 ();
1210 tree lhs_name
= gimple_get_lhs (stmt
);
1212 Value_Range
op1_range (TREE_TYPE (op1
));
1213 Value_Range
op2_range (TREE_TYPE (op2
));
1215 src
.get_operand (op1_range
, op1
);
1216 src
.get_operand (op2_range
, op2
);
1220 trio
= rel
->create_trio (lhs_name
, op1
, op2
);
1221 relation_kind op_op
= trio
.op1_op2 ();
1223 if (op_op
!= VREL_VARYING
)
1224 refine_using_relation (op1
, op1_range
, op2
, op2_range
, src
, op_op
);
1226 // If op1 == op2, create a new trio for this stmt.
1227 if (op1
== op2
&& gimple_range_ssa_p (op1
))
1229 relation_kind k
= get_identity_relation (op1
, op1_range
);
1230 trio
= relation_trio (trio
.lhs_op1 (), trio
.lhs_op2 (), k
);
1232 // Intersect with range for op2 based on lhs and op1.
1233 if (!handler
.calc_op2 (r
, lhs
, op1_range
, trio
))
1237 if ((idx
= tracer
.header ("compute op 2 (")))
1239 print_generic_expr (dump_file
, op2
, TDF_SLIM
);
1240 fprintf (dump_file
, ") at ");
1241 print_gimple_stmt (dump_file
, stmt
, 0, TDF_SLIM
);
1242 tracer
.print (idx
, "LHS = ");
1243 lhs
.dump (dump_file
);
1244 if (TREE_CODE (op1
) == SSA_NAME
)
1246 fprintf (dump_file
, ", ");
1247 print_generic_expr (dump_file
, op1
, TDF_SLIM
);
1248 fprintf (dump_file
, " = ");
1249 op1_range
.dump (dump_file
);
1251 fprintf (dump_file
, "\n");
1252 tracer
.print (idx
, "Computes ");
1253 print_generic_expr (dump_file
, op2
, TDF_SLIM
);
1254 fprintf (dump_file
, " = ");
1256 fprintf (dump_file
, " intersect Known range : ");
1257 op2_range
.dump (dump_file
);
1258 fputc ('\n', dump_file
);
1260 // Intersect the calculated result with the known result and return if done.
1261 r
.intersect (op2_range
);
1263 tracer
.trailer (idx
, " produces ", true, op2
, r
);
1267 // Calculate a range for NAME from both operand positions of S
1268 // assuming the result of the statement is LHS. Return the range in
1269 // R, or false if no range could be calculated.
1272 gori_compute::compute_operand1_and_operand2_range (vrange
&r
,
1273 gimple_range_op_handler
1278 value_relation
*rel
)
1280 Value_Range
op_range (TREE_TYPE (name
));
1282 Value_Range
vr (TREE_TYPE (handler
.operand2 ()));
1283 // Calculate a good a range through op2.
1284 if (!compute_operand2_range (vr
, handler
, lhs
, src
, rel
))
1286 gimple
*src_stmt
= SSA_NAME_DEF_STMT (handler
.operand2 ());
1287 gcc_checking_assert (src_stmt
);
1288 // Then feed this range back as the LHS of the defining statement.
1289 if (!compute_operand_range (r
, src_stmt
, vr
, name
, src
, rel
))
1292 // Now get the range thru op1.
1293 vr
.set_type (TREE_TYPE (handler
.operand1 ()));
1294 if (!compute_operand1_range (vr
, handler
, lhs
, src
, rel
))
1296 src_stmt
= SSA_NAME_DEF_STMT (handler
.operand1 ());
1297 gcc_checking_assert (src_stmt
);
1298 // Then feed this range back as the LHS of the defining statement.
1299 if (!compute_operand_range (op_range
, src_stmt
, vr
, name
, src
, rel
))
1302 // Both operands have to be simultaneously true, so perform an intersection.
1303 r
.intersect (op_range
);
1307 // Return TRUE if NAME can be recomputed on any edge exiting BB. If any
1308 // direct dependent is exported, it may also change the computed value of NAME.
1311 gori_compute::may_recompute_p (tree name
, basic_block bb
, int depth
)
1313 tree dep1
= depend1 (name
);
1314 tree dep2
= depend2 (name
);
1316 // If the first dependency is not set, there is no recomputation.
1317 // Dependencies reflect original IL, not current state. Check if the
1318 // SSA_NAME is still valid as well.
1322 // Don't recalculate PHIs or statements with side_effects.
1323 gimple
*s
= SSA_NAME_DEF_STMT (name
);
1324 if (is_a
<gphi
*> (s
) || gimple_has_side_effects (s
))
1329 // -1 indicates a default param, convert it to the real default.
1332 depth
= (int)param_ranger_recompute_depth
;
1333 gcc_checking_assert (depth
>= 1);
1336 bool res
= (bb
? is_export_p (dep1
, bb
) : is_export_p (dep1
));
1337 if (res
|| depth
<= 1)
1339 // Check another level of recomputation.
1340 return may_recompute_p (dep1
, bb
, --depth
);
1342 // Two dependencies terminate the depth of the search.
1344 return is_export_p (dep1
, bb
) || is_export_p (dep2
, bb
);
1346 return is_export_p (dep1
) || is_export_p (dep2
);
1349 // Return TRUE if NAME can be recomputed on edge E. If any direct dependent
1350 // is exported on edge E, it may change the computed value of NAME.
1353 gori_compute::may_recompute_p (tree name
, edge e
, int depth
)
1355 gcc_checking_assert (e
);
1356 return may_recompute_p (name
, e
->src
, depth
);
1360 // Return TRUE if a range can be calculated or recomputed for NAME on any
1364 gori_compute::has_edge_range_p (tree name
, basic_block bb
)
1366 // Check if NAME is an export or can be recomputed.
1368 return is_export_p (name
, bb
) || may_recompute_p (name
, bb
);
1370 // If no block is specified, check for anywhere in the IL.
1371 return is_export_p (name
) || may_recompute_p (name
);
1374 // Return TRUE if a range can be calculated or recomputed for NAME on edge E.
1377 gori_compute::has_edge_range_p (tree name
, edge e
)
1379 gcc_checking_assert (e
);
1380 return has_edge_range_p (name
, e
->src
);
1383 // Calculate a range on edge E and return it in R. Try to evaluate a
1384 // range for NAME on this edge. Return FALSE if this is either not a
1385 // control edge or NAME is not defined by this edge.
1388 gori_compute::outgoing_edge_range_p (vrange
&r
, edge e
, tree name
,
1393 if ((e
->flags
& m_not_executable_flag
))
1396 if (dump_file
&& (dump_flags
& TDF_DETAILS
))
1397 fprintf (dump_file
, "Outgoing edge %d->%d unexecutable.\n",
1398 e
->src
->index
, e
->dest
->index
);
1402 gcc_checking_assert (gimple_range_ssa_p (name
));
1404 // Determine if there is an outgoing edge.
1405 gimple
*stmt
= outgoing
.edge_range_p (lhs
, e
);
1409 fur_stmt
src (stmt
, &q
);
1410 // If NAME can be calculated on the edge, use that.
1411 if (is_export_p (name
, e
->src
))
1414 if ((idx
= tracer
.header ("outgoing_edge")))
1416 fprintf (dump_file
, " for ");
1417 print_generic_expr (dump_file
, name
, TDF_SLIM
);
1418 fprintf (dump_file
, " on edge %d->%d\n",
1419 e
->src
->index
, e
->dest
->index
);
1421 if ((res
= compute_operand_range (r
, stmt
, lhs
, name
, src
)))
1423 // Sometimes compatible types get interchanged. See PR97360.
1424 // Make sure we are returning the type of the thing we asked for.
1425 if (!r
.undefined_p () && r
.type () != TREE_TYPE (name
))
1427 gcc_checking_assert (range_compatible_p (r
.type (),
1429 range_cast (r
, TREE_TYPE (name
));
1433 tracer
.trailer (idx
, "outgoing_edge", res
, name
, r
);
1436 // If NAME isn't exported, check if it can be recomputed.
1437 else if (may_recompute_p (name
, e
))
1439 gimple
*def_stmt
= SSA_NAME_DEF_STMT (name
);
1441 if ((idx
= tracer
.header ("recomputation")))
1443 fprintf (dump_file
, " attempt on edge %d->%d for ",
1444 e
->src
->index
, e
->dest
->index
);
1445 print_gimple_stmt (dump_file
, def_stmt
, 0, TDF_SLIM
);
1447 // Simply calculate DEF_STMT on edge E using the range query Q.
1448 fold_range (r
, def_stmt
, e
, &q
);
1450 tracer
.trailer (idx
, "recomputation", true, name
, r
);
1456 // Given COND ? OP1 : OP2 with ranges R1 for OP1 and R2 for OP2, Use gori
1457 // to further resolve R1 and R2 if there are any dependencies between
1458 // OP1 and COND or OP2 and COND. All values can are to be calculated using SRC
1459 // as the origination source location for operands..
1460 // Effectively, use COND an the edge condition and solve for OP1 on the true
1461 // edge and OP2 on the false edge.
1464 gori_compute::condexpr_adjust (vrange
&r1
, vrange
&r2
, gimple
*, tree cond
,
1465 tree op1
, tree op2
, fur_source
&src
)
1467 tree ssa1
= gimple_range_ssa_p (op1
);
1468 tree ssa2
= gimple_range_ssa_p (op2
);
1471 if (TREE_CODE (cond
) != SSA_NAME
)
1473 gassign
*cond_def
= dyn_cast
<gassign
*> (SSA_NAME_DEF_STMT (cond
));
1475 || TREE_CODE_CLASS (gimple_assign_rhs_code (cond_def
)) != tcc_comparison
)
1477 tree type
= TREE_TYPE (gimple_assign_rhs1 (cond_def
));
1478 if (!range_compatible_p (type
, TREE_TYPE (gimple_assign_rhs2 (cond_def
))))
1480 range_op_handler
hand (gimple_assign_rhs_code (cond_def
));
1484 tree c1
= gimple_range_ssa_p (gimple_assign_rhs1 (cond_def
));
1485 tree c2
= gimple_range_ssa_p (gimple_assign_rhs2 (cond_def
));
1487 // Only solve if there is one SSA name in the condition.
1488 if ((!c1
&& !c2
) || (c1
&& c2
))
1491 // Pick up the current values of each part of the condition.
1492 tree rhs1
= gimple_assign_rhs1 (cond_def
);
1493 tree rhs2
= gimple_assign_rhs2 (cond_def
);
1494 Value_Range
cl (TREE_TYPE (rhs1
));
1495 Value_Range
cr (TREE_TYPE (rhs2
));
1496 src
.get_operand (cl
, rhs1
);
1497 src
.get_operand (cr
, rhs2
);
1499 tree cond_name
= c1
? c1
: c2
;
1500 gimple
*def_stmt
= SSA_NAME_DEF_STMT (cond_name
);
1502 // Evaluate the value of COND_NAME on the true and false edges, using either
1503 // the op1 or op2 routines based on its location.
1504 Value_Range
cond_true (type
), cond_false (type
);
1507 if (!hand
.op1_range (cond_false
, type
, m_bool_zero
, cr
))
1509 if (!hand
.op1_range (cond_true
, type
, m_bool_one
, cr
))
1511 cond_false
.intersect (cl
);
1512 cond_true
.intersect (cl
);
1516 if (!hand
.op2_range (cond_false
, type
, m_bool_zero
, cl
))
1518 if (!hand
.op2_range (cond_true
, type
, m_bool_one
, cl
))
1520 cond_false
.intersect (cr
);
1521 cond_true
.intersect (cr
);
1525 if ((idx
= tracer
.header ("cond_expr evaluation : ")))
1527 fprintf (dump_file
, " range1 = ");
1528 r1
.dump (dump_file
);
1529 fprintf (dump_file
, ", range2 = ");
1530 r1
.dump (dump_file
);
1531 fprintf (dump_file
, "\n");
1534 // Now solve for SSA1 or SSA2 if they are in the dependency chain.
1535 if (ssa1
&& in_chain_p (ssa1
, cond_name
))
1537 Value_Range
tmp1 (TREE_TYPE (ssa1
));
1538 if (compute_operand_range (tmp1
, def_stmt
, cond_true
, ssa1
, src
))
1539 r1
.intersect (tmp1
);
1541 if (ssa2
&& in_chain_p (ssa2
, cond_name
))
1543 Value_Range
tmp2 (TREE_TYPE (ssa2
));
1544 if (compute_operand_range (tmp2
, def_stmt
, cond_false
, ssa2
, src
))
1545 r2
.intersect (tmp2
);
1549 tracer
.print (idx
, "outgoing: range1 = ");
1550 r1
.dump (dump_file
);
1551 fprintf (dump_file
, ", range2 = ");
1552 r1
.dump (dump_file
);
1553 fprintf (dump_file
, "\n");
1554 tracer
.trailer (idx
, "cond_expr", true, cond_name
, cond_true
);
1559 // Dump what is known to GORI computes to listing file F.
1562 gori_compute::dump (FILE *f
)
1567 // ------------------------------------------------------------------------
1568 // GORI iterator. Although we have bitmap iterators, don't expose that it
1569 // is currently a bitmap. Use an export iterator to hide future changes.
1571 // Construct a basic iterator over an export bitmap.
1573 gori_export_iterator::gori_export_iterator (bitmap b
)
1577 bmp_iter_set_init (&bi
, b
, 1, &y
);
1581 // Move to the next export bitmap spot.
1584 gori_export_iterator::next ()
1586 bmp_iter_next (&bi
, &y
);
1590 // Fetch the name of the next export in the export list. Return NULL if
1591 // iteration is done.
1594 gori_export_iterator::get_name ()
1599 while (bmp_iter_set (&bi
, &y
))
1601 tree t
= ssa_name (y
);