[patch] Predictive commoning, updated
Zdenek Dvorak
rakdver@kam.mff.cuni.cz
Wed May 16 14:04:00 GMT 2007
Hello,
here is the (hopefully) final version of the patch for predictive
commoning. In addition to the changes required in the review
(for more comments see http://gcc.gnu.org/ml/gcc-patches/2007-05/msg00235.html),
the following changes were made:
1) The newly rewritten data reference analysis of tree-data-ref.c is
used, significantly simplifying some of the functions
(suitable_reference_p, determine_offset).
2) One problem got exposed -- cfg manipulations in loop_version may
cause phi nodes to be reallocated, and pointers to them that we
store in the structures may get invalidated. To avoid this problem,
a bit of magic had to be added before tree_transform_and_unroll_loop
call and to execute_pred_commoning_cbck (to save the ssa names
defined by the phi nodes before the unrolling call and to restore
phi nodes using them afterwards).
Since especially the changes described in 1) are quite significant
difference with respect to the approved version, I think I need approval
for them as well. I have bootstrapped & regtested this version of the
patch with predictive commoning enabled on x68_64.
Zdenek
* doc/passes.texi: Document predictive commoning.
* doc/invoke.texi (-fpredictive-commoning): Document.
* opts.c (decode_options): Enable flag_predictive_commoning on -O3.
* tree-ssa-loop-im.c (get_lsm_tmp_name): Export. Allow
adding indices to the generated name.
(schedule_sm): Pass 0 to get_lsm_tmp_name.
* tree-ssa-loop-niter.c (stmt_dominates_stmt_p): Export.
* tree-pretty-print.c (op_symbol_1): Renamed to ...
(op_symbol_code): ... and exported.
(dump_omp_clause, op_symbol): Use op_symbol_code
instead of op_symbol_1.
* tree-pass.h (pass_predcom): Declare.
* timevar.def (TV_PREDCOM): New timevar.
* tree-ssa-loop.c (run_tree_predictive_commoning,
gate_tree_predictive_commoning, pass_predcom): New.
* tree-data-ref.c (find_data_references_in_loop): Find the
references in dominance order.
(canonicalize_base_object_address): Ensure that the result has
pointer type.
(dr_analyze_innermost): Export.
(create_data_ref): Code to fail for references with invariant
address moved ...
(find_data_references_in_stmt): ... here.
* tree-data-ref.h (dr_analyze_innermost): Declare.
* tree-affine.c: Include tree-gimple.h and hashtab.h.
(aff_combination_find_elt, name_expansion_hash,
name_expansion_eq, tree_to_aff_combination_expand,
double_int_constant_multiple_p, aff_combination_constant_multiple_p):
New functions.
* tree-affine.h (aff_combination_constant_multiple_p,
tree_to_aff_combination_expand): Declare.
* tree-predcom.c: New file.
* common.opt (fpredictive-commoning): New option.
* tree-flow.h (op_symbol_code, tree_predictive_commoning,
stmt_dominates_stmt_p, get_lsm_tmp_name): Declare.
* Makefile.in (tree-predcom.o): Add.
(tree-affine.o): Add TREE_GIMPLE_H dependency.
* passes.c (init_optimization_passes): Add dceloop after
copy propagation in loop optimizer. Add predictive commoning
to loop optimizer passes.
* gcc.dg/tree-ssa/predcom-1.c: New test.
* gcc.dg/tree-ssa/predcom-2.c: New test.
* gcc.dg/tree-ssa/predcom-3.c: New test.
* gcc.dg/tree-ssa/predcom-4.c: New test.
* gcc.dg/tree-ssa/predcom-5.c: New test.
* gcc.dg/vect/dump-tree-dceloop-pr26359.c: Test dceloop2 dumps.
Index: doc/passes.texi
===================================================================
*** doc/passes.texi (revision 124766)
--- doc/passes.texi (working copy)
*************** This pass completely unrolls loops with
*** 602,607 ****
--- 602,618 ----
is located in @file{tree-ssa-loop-ivcanon.c} and described by
@code{pass_complete_unroll}.
+ @item Predictive commoning
+
+ This pass makes the code reuse the computations from the previous
+ iterations of the loops, especially loads and stores to memory.
+ It does so by storing the values of these computations to a bank
+ of temporary variables that are rotated at the end of loop. To avoid
+ the need for this rotation, the loop is then unrolled and the copies
+ of the loop body are rewritten to use the appropriate version of
+ the temporary variable. This pass is located in @file{tree-predcom.c}
+ and described by @code{pass_predcom}.
+
@item Array prefetching
This pass issues prefetch instructions for array references inside
Index: doc/invoke.texi
===================================================================
*** doc/invoke.texi (revision 124766)
--- doc/invoke.texi (working copy)
*************** Objective-C and Objective-C++ Dialects}.
*** 333,339 ****
-ffinite-math-only -fno-signed-zeros @gol
-fno-toplevel-reorder -fno-trapping-math -fno-zero-initialized-in-bss @gol
-fomit-frame-pointer -foptimize-register-move @gol
! -foptimize-sibling-calls -fprefetch-loop-arrays @gol
-fprofile-generate -fprofile-use @gol
-fregmove -frename-registers @gol
-freorder-blocks -freorder-blocks-and-partition -freorder-functions @gol
--- 333,339 ----
-ffinite-math-only -fno-signed-zeros @gol
-fno-toplevel-reorder -fno-trapping-math -fno-zero-initialized-in-bss @gol
-fomit-frame-pointer -foptimize-register-move @gol
! -foptimize-sibling-calls -fpredictive-commoning -fprefetch-loop-arrays @gol
-fprofile-generate -fprofile-use @gol
-fregmove -frename-registers @gol
-freorder-blocks -freorder-blocks-and-partition -freorder-functions @gol
*************** invoking @option{-O2} on programs that u
*** 4985,4991 ****
@opindex O3
Optimize yet more. @option{-O3} turns on all optimizations specified by
@option{-O2} and also turns on the @option{-finline-functions},
! @option{-funswitch-loops} and @option{-fgcse-after-reload} options.
@item -O0
@opindex O0
--- 4985,4992 ----
@opindex O3
Optimize yet more. @option{-O3} turns on all optimizations specified by
@option{-O2} and also turns on the @option{-finline-functions},
! @option{-funswitch-loops}, @option{-fpredictive-commoning} and
! @option{-fgcse-after-reload} options.
@item -O0
@opindex O0
*************** This optimization is enabled by default.
*** 5696,5701 ****
--- 5697,5710 ----
With this option, the compiler will create multiple copies of some
local variables when unrolling a loop which can result in superior code.
+ @item -fpredictive-commoning
+ @opindex fpredictive-commoning
+ Perform predictive commoning optimization, i.e., reusing computations
+ (especially memory loads and stores) performed in previous
+ iterations of loops.
+
+ This option is enabled at level @option{-O3}.
+
@item -fprefetch-loop-arrays
@opindex fprefetch-loop-arrays
If supported by the target machine, generate instructions to prefetch
Index: tree-ssa-loop-im.c
===================================================================
*** tree-ssa-loop-im.c (revision 124766)
--- tree-ssa-loop-im.c (working copy)
*************** gen_lsm_tmp_name (tree ref)
*** 1116,1129 ****
}
/* Determines name for temporary variable that replaces REF.
! The name is accumulated into the lsm_tmp_name variable. */
! static char *
! get_lsm_tmp_name (tree ref)
{
lsm_tmp_name_length = 0;
gen_lsm_tmp_name (ref);
lsm_tmp_name_add ("_lsm");
return lsm_tmp_name;
}
--- 1116,1138 ----
}
/* Determines name for temporary variable that replaces REF.
! The name is accumulated into the lsm_tmp_name variable.
! N is added to the name of the temporary. */
! char *
! get_lsm_tmp_name (tree ref, unsigned n)
{
+ char ns[2];
+
lsm_tmp_name_length = 0;
gen_lsm_tmp_name (ref);
lsm_tmp_name_add ("_lsm");
+ if (n < 10)
+ {
+ ns[0] = '0' + n;
+ ns[1] = 0;
+ lsm_tmp_name_add (ns);
+ }
return lsm_tmp_name;
}
*************** schedule_sm (struct loop *loop, VEC (edg
*** 1153,1159 ****
}
tmp_var = make_rename_temp (TREE_TYPE (ref),
! get_lsm_tmp_name (ref));
fmt_data.loop = loop;
fmt_data.orig_loop = loop;
--- 1162,1168 ----
}
tmp_var = make_rename_temp (TREE_TYPE (ref),
! get_lsm_tmp_name (ref, ~0));
fmt_data.loop = loop;
fmt_data.orig_loop = loop;
Index: tree-ssa-loop-niter.c
===================================================================
*** tree-ssa-loop-niter.c (revision 124766)
--- tree-ssa-loop-niter.c (working copy)
*************** estimate_numbers_of_iterations (void)
*** 2816,2822 ****
/* Returns true if statement S1 dominates statement S2. */
! static bool
stmt_dominates_stmt_p (tree s1, tree s2)
{
basic_block bb1 = bb_for_stmt (s1), bb2 = bb_for_stmt (s2);
--- 2816,2822 ----
/* Returns true if statement S1 dominates statement S2. */
! bool
stmt_dominates_stmt_p (tree s1, tree s2)
{
basic_block bb1 = bb_for_stmt (s1), bb2 = bb_for_stmt (s2);
Index: tree-pretty-print.c
===================================================================
*** tree-pretty-print.c (revision 124766)
--- tree-pretty-print.c (working copy)
*************** Software Foundation, 51 Franklin Street,
*** 37,43 ****
/* Local functions, macros and variables. */
static int op_prio (tree);
- static const char *op_symbol_1 (enum tree_code);
static const char *op_symbol (tree);
static void pretty_print_string (pretty_printer *, const char*);
static void print_call_name (pretty_printer *, tree);
--- 37,42 ----
*************** dump_omp_clause (pretty_printer *buffer,
*** 296,302 ****
case OMP_CLAUSE_REDUCTION:
pp_string (buffer, "reduction(");
! pp_string (buffer, op_symbol_1 (OMP_CLAUSE_REDUCTION_CODE (clause)));
pp_character (buffer, ':');
dump_generic_node (buffer, OMP_CLAUSE_DECL (clause),
spc, flags, false);
--- 295,301 ----
case OMP_CLAUSE_REDUCTION:
pp_string (buffer, "reduction(");
! pp_string (buffer, op_symbol_code (OMP_CLAUSE_REDUCTION_CODE (clause)));
pp_character (buffer, ':');
dump_generic_node (buffer, OMP_CLAUSE_DECL (clause),
spc, flags, false);
*************** op_prio (tree op)
*** 2368,2377 ****
}
! /* Return the symbol associated with operator OP. */
! static const char *
! op_symbol_1 (enum tree_code code)
{
switch (code)
{
--- 2367,2376 ----
}
! /* Return the symbol associated with operator CODE. */
! const char *
! op_symbol_code (enum tree_code code)
{
switch (code)
{
*************** op_symbol_1 (enum tree_code code)
*** 2535,2544 ****
}
}
static const char *
op_symbol (tree op)
{
! return op_symbol_1 (TREE_CODE (op));
}
/* Prints the name of a CALL_EXPR. */
--- 2534,2545 ----
}
}
+ /* Return the symbol associated with operator OP. */
+
static const char *
op_symbol (tree op)
{
! return op_symbol_code (TREE_CODE (op));
}
/* Prints the name of a CALL_EXPR. */
Index: tree-pass.h
===================================================================
*** tree-pass.h (revision 124766)
--- tree-pass.h (working copy)
*************** extern struct tree_opt_pass pass_tree_lo
*** 247,252 ****
--- 247,253 ----
extern struct tree_opt_pass pass_tree_loop_init;
extern struct tree_opt_pass pass_lim;
extern struct tree_opt_pass pass_tree_unswitch;
+ extern struct tree_opt_pass pass_predcom;
extern struct tree_opt_pass pass_iv_canon;
extern struct tree_opt_pass pass_scev_cprop;
extern struct tree_opt_pass pass_empty_loop;
Index: testsuite/gcc.dg/tree-ssa/predcom-3.c
===================================================================
*** testsuite/gcc.dg/tree-ssa/predcom-3.c (revision 0)
--- testsuite/gcc.dg/tree-ssa/predcom-3.c (revision 0)
***************
*** 0 ****
--- 1,16 ----
+ /* { dg-do compile } */
+ /* { dg-options "-O2 -fpredictive-commoning -fdump-tree-pcom-details" } */
+
+ int a[1000], b[1000];
+
+ void test(void)
+ {
+ int i;
+
+ for (i = 1; i < 999; i++)
+ b[i] = (a[i + 1] + a[i] + a[i - 1]) / 3;
+ }
+
+ /* Verify that we used 3 temporary variables for the loop. */
+ /* { dg-final { scan-tree-dump-times "Unrolling 3 times." 1 "pcom"} } */
+ /* { dg-final { cleanup-tree-dump "pcom" } } */
Index: testsuite/gcc.dg/tree-ssa/predcom-4.c
===================================================================
*** testsuite/gcc.dg/tree-ssa/predcom-4.c (revision 0)
--- testsuite/gcc.dg/tree-ssa/predcom-4.c (revision 0)
***************
*** 0 ****
--- 1,30 ----
+ /* { dg-do compile } */
+ /* { dg-do run } */
+ /* { dg-options "-O2 -fpredictive-commoning -fdump-tree-pcom-details" } */
+
+ /* Test for predictive commoning of expressions, without reassociation. */
+
+ void abort (void);
+
+ int a[1000], b[1000], c[1000];
+
+ int main(void)
+ {
+ int i;
+
+ for (i = 0; i < 1000; i++)
+ a[i] = b[i] = i;
+
+ for (i = 1; i < 998; i++)
+ c[i] = a[i + 2] * b[i + 1] - b[i - 1] * a[i];
+
+ for (i = 1; i < 998; i++)
+ if (c[i] != 4 * i + 2)
+ abort ();
+
+ return 0;
+ }
+
+ /* { dg-final { scan-tree-dump-times "Combination" 1 "pcom"} } */
+ /* { dg-final { scan-tree-dump-times "Unrolling 3 times." 1 "pcom"} } */
+ /* { dg-final { cleanup-tree-dump "pcom" } } */
Index: testsuite/gcc.dg/tree-ssa/predcom-5.c
===================================================================
*** testsuite/gcc.dg/tree-ssa/predcom-5.c (revision 0)
--- testsuite/gcc.dg/tree-ssa/predcom-5.c (revision 0)
***************
*** 0 ****
--- 1,30 ----
+ /* { dg-do compile } */
+ /* { dg-do run } */
+ /* { dg-options "-O2 -fpredictive-commoning -fdump-tree-pcom-details" } */
+
+ /* Test for predictive commoning of expressions, with reassociation. */
+
+ void abort (void);
+
+ unsigned a[1000], b[1000], c[1000], d[1000];
+
+ int main(void)
+ {
+ unsigned i;
+
+ for (i = 0; i < 1000; i++)
+ a[i] = b[i] = d[i] = i;
+
+ for (i = 1; i < 998; i++)
+ c[i] = d[i + 1] * a[i + 2] * b[i + 1] - b[i - 1] * a[i] * d[i - 1];
+
+ for (i = 1; i < 998; i++)
+ if (c[i] != (i+1)*(i+2)*(i+1) - (i - 1) * i * (i - 1))
+ abort ();
+
+ return 0;
+ }
+
+ /* { dg-final { scan-tree-dump-times "Combination" 2 "pcom"} } */
+ /* { dg-final { scan-tree-dump-times "Unrolling 3 times." 1 "pcom"} } */
+ /* { dg-final { cleanup-tree-dump "pcom" } } */
Index: testsuite/gcc.dg/tree-ssa/predcom-1.c
===================================================================
*** testsuite/gcc.dg/tree-ssa/predcom-1.c (revision 0)
--- testsuite/gcc.dg/tree-ssa/predcom-1.c (revision 0)
***************
*** 0 ****
--- 1,49 ----
+ /* { dg-do compile } */
+ /* { dg-do run } */
+ /* { dg-options "-O2 -fpredictive-commoning -fdump-tree-pcom-details" } */
+
+ void abort (void);
+
+ unsigned fib[1000];
+
+ void count_fib(void)
+ {
+ int i;
+
+ fib[0] = 0;
+ fib[1] = 1;
+ for (i = 2; i < 1000; i++)
+ fib[i] = (fib[i-1] + fib[i - 2]) & 0xffff;
+ }
+
+ unsigned avg[1000];
+
+ void count_averages(int n)
+ {
+ int i;
+
+ for (i = 1; i < n; i++)
+ avg[i] = ((fib[i - 1] + fib[i] + fib[i + 1]) / 3) & 0xffff;
+ }
+
+ int main(void)
+ {
+ count_fib ();
+ count_averages (999);
+
+ if (fib[19] != 4181 || avg[19] != 4510)
+ abort ();
+
+ if (fib[999] != 162 || avg[998] != 21953)
+ abort ();
+
+ return 0;
+ }
+
+ /* Verify that both loops were transformed and unrolled. */
+ /* { dg-final { scan-tree-dump-times "Unrolling 2 times." 2 "pcom"} } */
+
+ /* Also check that we undid the transformation previously made by PRE. */
+ /* { dg-final { scan-tree-dump-times "looparound ref" 1 "pcom"} } */
+
+ /* { dg-final { cleanup-tree-dump "pcom" } } */
Index: testsuite/gcc.dg/tree-ssa/predcom-2.c
===================================================================
*** testsuite/gcc.dg/tree-ssa/predcom-2.c (revision 0)
--- testsuite/gcc.dg/tree-ssa/predcom-2.c (revision 0)
***************
*** 0 ****
--- 1,45 ----
+ /* { dg-do compile } */
+ /* { dg-do run } */
+ /* { dg-options "-O2 -fpredictive-commoning -fdump-tree-pcom-details" } */
+
+ void abort (void);
+
+ int fib[1000];
+
+ void count_fib(void)
+ {
+ int i;
+
+ fib[0] = 0;
+ fib[1] = 1;
+ for (i = 2; i < 1000; i++)
+ fib[i] = (fib[i-1] + fib[i - 2]) & 0xffff;
+ }
+
+ int avg[1000];
+
+ void count_averages(void)
+ {
+ int i;
+
+ for (i = 1; i < 999; i++)
+ avg[i] = ((fib[i - 1] + fib[i] + fib[i + 1]) / 3) & 0xffff;
+ }
+
+ int main(void)
+ {
+ count_fib ();
+ count_averages ();
+
+ if (fib[19] != 4181 || avg[19] != 4510)
+ abort ();
+
+ if (fib[999] != 162 || avg[998] != 21953)
+ abort ();
+
+ return 0;
+ }
+
+ /* Verify that both loops were transformed and unrolled. */
+ /* { dg-final { scan-tree-dump-times "Unrolling 2 times." 2 "pcom"} } */
+ /* { dg-final { cleanup-tree-dump "pcom" } } */
Index: testsuite/gcc.dg/vect/dump-tree-dceloop-pr26359.c
===================================================================
*** testsuite/gcc.dg/vect/dump-tree-dceloop-pr26359.c (revision 124766)
--- testsuite/gcc.dg/vect/dump-tree-dceloop-pr26359.c (working copy)
*************** foo () {
*** 11,16 ****
}
}
! /* { dg-final { scan-tree-dump-times "Deleting : vect_" 0 "dceloop" } } */
! /* { dg-final { cleanup-tree-dump "dceloop" } } */
/* { dg-final { cleanup-tree-dump "vect" } } */
--- 11,16 ----
}
}
! /* { dg-final { scan-tree-dump-times "Deleting : vect_" 0 "dceloop2" } } */
! /* { dg-final { cleanup-tree-dump "dceloop2" } } */
/* { dg-final { cleanup-tree-dump "vect" } } */
Index: opts.c
===================================================================
*** opts.c (revision 124766)
--- opts.c (working copy)
*************** decode_options (unsigned int argc, const
*** 767,772 ****
--- 767,773 ----
if (optimize >= 3)
{
+ flag_predictive_commoning = 1;
flag_inline_functions = 1;
flag_unswitch_loops = 1;
flag_gcse_after_reload = 1;
Index: timevar.def
===================================================================
*** timevar.def (revision 124766)
--- timevar.def (working copy)
*************** DEFTIMEVAR (TV_TREE_LINEAR_TRANSFORM , "
*** 112,117 ****
--- 112,118 ----
DEFTIMEVAR (TV_CHECK_DATA_DEPS , "tree check data dependences")
DEFTIMEVAR (TV_TREE_PREFETCH , "tree prefetching")
DEFTIMEVAR (TV_TREE_LOOP_IVOPTS , "tree iv optimization")
+ DEFTIMEVAR (TV_PREDCOM , "predictive commoning")
DEFTIMEVAR (TV_TREE_LOOP_INIT , "tree loop init")
DEFTIMEVAR (TV_TREE_LOOP_FINI , "tree loop fini")
DEFTIMEVAR (TV_TREE_CH , "tree copy headers")
Index: tree-ssa-loop.c
===================================================================
*** tree-ssa-loop.c (revision 124766)
--- tree-ssa-loop.c (working copy)
*************** struct tree_opt_pass pass_tree_unswitch
*** 176,181 ****
--- 176,217 ----
0 /* letter */
};
+ /* Predictive commoning. */
+
+ static unsigned
+ run_tree_predictive_commoning (void)
+ {
+ if (!current_loops)
+ return 0;
+
+ tree_predictive_commoning ();
+ return 0;
+ }
+
+ static bool
+ gate_tree_predictive_commoning (void)
+ {
+ return flag_predictive_commoning != 0;
+ }
+
+ struct tree_opt_pass pass_predcom =
+ {
+ "pcom", /* name */
+ gate_tree_predictive_commoning, /* gate */
+ run_tree_predictive_commoning, /* execute */
+ NULL, /* sub */
+ NULL, /* next */
+ 0, /* static_pass_number */
+ TV_PREDCOM, /* tv_id */
+ PROP_cfg, /* properties_required */
+ 0, /* properties_provided */
+ 0, /* properties_destroyed */
+ 0, /* todo_flags_start */
+ TODO_dump_func | TODO_verify_loops
+ | TODO_update_ssa_only_virtuals, /* todo_flags_finish */
+ 0 /* letter */
+ };
+
/* Loop autovectorization. */
static unsigned int
Index: tree-data-ref.c
===================================================================
*** tree-data-ref.c (revision 124766)
--- tree-data-ref.c (working copy)
*************** split_constant_offset (tree exp, tree *v
*** 573,580 ****
--- 573,587 ----
static tree
canonicalize_base_object_address (tree addr)
{
+ tree orig = addr;
+
STRIP_NOPS (addr);
+ /* The base address may be obtained by casting from integer, in that case
+ keep the cast. */
+ if (!POINTER_TYPE_P (TREE_TYPE (addr)))
+ return orig;
+
if (TREE_CODE (addr) != ADDR_EXPR)
return addr;
*************** canonicalize_base_object_address (tree a
*** 584,590 ****
/* Analyzes the behavior of the memory reference DR in the innermost loop that
contains it. */
! static void
dr_analyze_innermost (struct data_reference *dr)
{
tree stmt = DR_STMT (dr);
--- 591,597 ----
/* Analyzes the behavior of the memory reference DR in the innermost loop that
contains it. */
! void
dr_analyze_innermost (struct data_reference *dr)
{
tree stmt = DR_STMT (dr);
*************** create_data_ref (struct loop *nest, tree
*** 804,819 ****
fprintf (dump_file, "\n");
}
- /* FIXME -- data dependence analysis does not work correctly for objects with
- invariant addresses. Let us fail here until the problem is fixed. */
- if (dr_address_invariant_p (dr))
- {
- free_data_ref (dr);
- dr = NULL;
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "\tFAILED as dr address is invariant\n");
- }
-
return dr;
}
--- 811,816 ----
*************** find_data_references_in_stmt (struct loo
*** 3965,3977 ****
for (i = 0; VEC_iterate (data_ref_loc, references, i, ref); i++)
{
dr = create_data_ref (nest, *ref->pos, stmt, ref->is_read);
! if (dr)
! VEC_safe_push (data_reference_p, heap, *datarefs, dr);
! else
{
ret = false;
break;
}
}
VEC_free (data_ref_loc, heap, references);
return ret;
--- 3962,3981 ----
for (i = 0; VEC_iterate (data_ref_loc, references, i, ref); i++)
{
dr = create_data_ref (nest, *ref->pos, stmt, ref->is_read);
! gcc_assert (dr != NULL);
!
! /* FIXME -- data dependence analysis does not work correctly for objects with
! invariant addresses. Let us fail here until the problem is fixed. */
! if (dr_address_invariant_p (dr))
{
+ free_data_ref (dr);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\tFAILED as dr address is invariant\n");
ret = false;
break;
}
+
+ VEC_safe_push (data_reference_p, heap, *datarefs, dr);
}
VEC_free (data_ref_loc, heap, references);
return ret;
*************** find_data_references_in_loop (struct loo
*** 3992,3998 ****
unsigned int i;
block_stmt_iterator bsi;
! bbs = get_loop_body (loop);
for (i = 0; i < loop->num_nodes; i++)
{
--- 3996,4002 ----
unsigned int i;
block_stmt_iterator bsi;
! bbs = get_loop_body_in_dom_order (loop);
for (i = 0; i < loop->num_nodes; i++)
{
Index: tree-data-ref.h
===================================================================
*** tree-data-ref.h (revision 124766)
--- tree-data-ref.h (working copy)
*************** DEF_VEC_O (data_ref_loc);
*** 299,304 ****
--- 299,305 ----
DEF_VEC_ALLOC_O (data_ref_loc, heap);
bool get_references_in_stmt (tree, VEC (data_ref_loc, heap) **);
+ void dr_analyze_innermost (struct data_reference *);
extern void compute_data_dependences_for_loop (struct loop *, bool,
VEC (data_reference_p, heap) **,
VEC (ddr_p, heap) **);
Index: tree-affine.c
===================================================================
*** tree-affine.c (revision 124766)
--- tree-affine.c (working copy)
*************** Software Foundation, 51 Franklin Street,
*** 29,35 ****
--- 29,37 ----
#include "output.h"
#include "diagnostic.h"
#include "tree-dump.h"
+ #include "pointer-set.h"
#include "tree-affine.h"
+ #include "tree-gimple.h"
/* Extends CST as appropriate for the affine combinations COMB. */
*************** aff_combination_mult (aff_tree *c1, aff_
*** 493,495 ****
--- 495,706 ----
aff_combination_add_product (c1, double_int_one, c2->rest, r);
aff_combination_add_product (c1, c2->offset, NULL, r);
}
+
+ /* Returns the element of COMB whose value is VAL, or NULL if no such
+ element exists. If IDX is not NULL, it is set to the index of VAL in
+ COMB. */
+
+ static struct aff_comb_elt *
+ aff_combination_find_elt (aff_tree *comb, tree val, unsigned *idx)
+ {
+ unsigned i;
+
+ for (i = 0; i < comb->n; i++)
+ if (operand_equal_p (comb->elts[i].val, val, 0))
+ {
+ if (idx)
+ *idx = i;
+
+ return &comb->elts[i];
+ }
+
+ return NULL;
+ }
+
+ /* Element of the cache that maps ssa name NAME to its expanded form
+ as an affine expression EXPANSION. */
+
+ struct name_expansion
+ {
+ aff_tree expansion;
+
+ /* True if the expansion for the name is just being generated. */
+ unsigned in_progress : 1;
+ };
+
+ /* Similar to tree_to_aff_combination, but follows SSA name definitions
+ and expands them recursively. CACHE is used to cache the expansions
+ of the ssa names, to avoid exponential time complexity for cases
+ like
+
+ a1 = a0 + a0;
+ a2 = a1 + a1;
+ a3 = a2 + a2;
+ ... */
+
+ void
+ tree_to_aff_combination_expand (tree expr, tree type, aff_tree *comb,
+ struct pointer_map_t **cache)
+ {
+ unsigned i;
+ aff_tree to_add, current, curre;
+ tree e, def, rhs;
+ double_int scale;
+ void **slot;
+ struct name_expansion *exp;
+
+ tree_to_aff_combination (expr, type, comb);
+ aff_combination_zero (&to_add, type);
+ for (i = 0; i < comb->n; i++)
+ {
+ e = comb->elts[i].val;
+ if (TREE_CODE (e) != SSA_NAME)
+ continue;
+ def = SSA_NAME_DEF_STMT (e);
+ if (TREE_CODE (def) != GIMPLE_MODIFY_STMT
+ || GIMPLE_STMT_OPERAND (def, 0) != e)
+ continue;
+
+ rhs = GIMPLE_STMT_OPERAND (def, 1);
+ if (TREE_CODE (rhs) != SSA_NAME
+ && !EXPR_P (rhs)
+ && !is_gimple_min_invariant (rhs))
+ continue;
+
+ /* We do not know whether the reference retains its value at the
+ place where the expansion is used. */
+ if (REFERENCE_CLASS_P (rhs))
+ continue;
+
+ if (!*cache)
+ *cache = pointer_map_create ();
+ slot = pointer_map_insert (*cache, e);
+ exp = *slot;
+
+ if (!exp)
+ {
+ exp = XNEW (struct name_expansion);
+ exp->in_progress = 1;
+ *slot = exp;
+ tree_to_aff_combination_expand (rhs, type, ¤t, cache);
+ exp->expansion = current;
+ exp->in_progress = 0;
+ }
+ else
+ {
+ /* Since we follow the definitions in the SSA form, we should not
+ enter a cycle unless we pass through a phi node. */
+ gcc_assert (!exp->in_progress);
+ current = exp->expansion;
+ }
+
+ /* Accumulate the new terms to TO_ADD, so that we do not modify
+ COMB while traversing it; include the term -coef * E, to remove
+ it from COMB. */
+ scale = comb->elts[i].coef;
+ aff_combination_zero (&curre, type);
+ aff_combination_add_elt (&curre, e, double_int_neg (scale));
+ aff_combination_scale (¤t, scale);
+ aff_combination_add (&to_add, ¤t);
+ aff_combination_add (&to_add, &curre);
+ }
+ aff_combination_add (comb, &to_add);
+ }
+
+ /* Frees memory occupied by struct name_expansion in *VALUE. Callback for
+ pointer_map_traverse. */
+
+ static bool
+ free_name_expansion (void *key ATTRIBUTE_UNUSED, void **value,
+ void *data ATTRIBUTE_UNUSED)
+ {
+ struct name_expansion *exp = *value;
+
+ free (exp);
+ return true;
+ }
+
+ /* Frees memory allocated for the CACHE used by
+ tree_to_aff_combination_expand. */
+
+ void
+ free_affine_expand_cache (struct pointer_map_t **cache)
+ {
+ if (!*cache)
+ return;
+
+ pointer_map_traverse (*cache, free_name_expansion, NULL);
+ pointer_map_destroy (*cache);
+ *cache = NULL;
+ }
+
+ /* If VAL != CST * DIV for any constant CST, returns false.
+ Otherwise, if VAL != 0 (and hence CST != 0), and *MULT_SET is true,
+ additionally compares CST and MULT, and if they are different,
+ returns false. Finally, if neither of these two cases occcur,
+ true is returned, and if CST != 0, CST is stored to MULT and
+ MULT_SET is set to true. */
+
+ static bool
+ double_int_constant_multiple_p (double_int val, double_int div,
+ bool *mult_set, double_int *mult)
+ {
+ double_int rem, cst;
+
+ if (double_int_zero_p (val))
+ return true;
+
+ if (double_int_zero_p (div))
+ return false;
+
+ cst = double_int_sdivmod (val, div, FLOOR_DIV_EXPR, &rem);
+ if (!double_int_zero_p (rem))
+ return false;
+
+ if (*mult_set && !double_int_equal_p (*mult, cst))
+ return false;
+
+ *mult_set = true;
+ *mult = cst;
+ return true;
+ }
+
+ /* Returns true if VAL = X * DIV for some constant X. If this is the case,
+ X is stored to MULT. */
+
+ bool
+ aff_combination_constant_multiple_p (aff_tree *val, aff_tree *div,
+ double_int *mult)
+ {
+ bool mult_set = false;
+ unsigned i;
+
+ if (val->n == 0 && double_int_zero_p (val->offset))
+ {
+ *mult = double_int_zero;
+ return true;
+ }
+ if (val->n != div->n)
+ return false;
+
+ if (val->rest || div->rest)
+ return false;
+
+ if (!double_int_constant_multiple_p (val->offset, div->offset,
+ &mult_set, mult))
+ return false;
+
+ for (i = 0; i < div->n; i++)
+ {
+ struct aff_comb_elt *elt
+ = aff_combination_find_elt (val, div->elts[i].val, NULL);
+ if (!elt)
+ return false;
+ if (!double_int_constant_multiple_p (elt->coef, div->elts[i].coef,
+ &mult_set, mult))
+ return false;
+ }
+
+ gcc_assert (mult_set);
+ return true;
+ }
Index: tree-affine.h
===================================================================
*** tree-affine.h (revision 124766)
--- tree-affine.h (working copy)
*************** void aff_combination_convert (aff_tree *
*** 70,72 ****
--- 70,76 ----
void tree_to_aff_combination (tree, tree, aff_tree *);
tree aff_combination_to_tree (aff_tree *);
void unshare_aff_combination (aff_tree *);
+ bool aff_combination_constant_multiple_p (aff_tree *, aff_tree *, double_int *);
+ void tree_to_aff_combination_expand (tree, tree, aff_tree *,
+ struct pointer_map_t **);
+ void free_affine_expand_cache (struct pointer_map_t **);
Index: tree-predcom.c
===================================================================
*** tree-predcom.c (revision 0)
--- tree-predcom.c (revision 0)
***************
*** 0 ****
--- 1,2567 ----
+ /* Predictive commoning.
+ Copyright (C) 2005 Free Software Foundation, Inc.
+
+ This file is part of GCC.
+
+ GCC is free software; you can redistribute it and/or modify it
+ under the terms of the GNU General Public License as published by the
+ Free Software Foundation; either version 2, or (at your option) any
+ later version.
+
+ GCC is distributed in the hope that it will be useful, but WITHOUT
+ ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with GCC; see the file COPYING. If not, write to the Free
+ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+ 02110-1301, USA. */
+
+ /* This file implements the predictive commoning optimization. Predictive
+ commoning can be viewed as CSE around a loop, and with some improvements,
+ as generalized strength reduction-- i.e., reusing values computed in
+ earlier iterations of a loop in the later ones. So far, the pass only
+ handles the most useful case, that is, reusing values of memory references.
+ If you think this is all just a special case of PRE, you are sort of right;
+ however, concentrating on loops is simpler, and makes it possible to
+ incorporate data dependence analysis to detect the opportunities, perform
+ loop unrolling to avoid copies together with renaming immediately,
+ and if needed, we could also take register pressure into account.
+
+ Let us demonstrate what is done on an example:
+
+ for (i = 0; i < 100; i++)
+ {
+ a[i+2] = a[i] + a[i+1];
+ b[10] = b[10] + i;
+ c[i] = c[99 - i];
+ d[i] = d[i + 1];
+ }
+
+ 1) We find data references in the loop, and split them to mutually
+ independent groups (i.e., we find components of a data dependence
+ graph). We ignore read-read dependences whose distance is not constant.
+ (TODO -- we could also ignore antidependences). In this example, we
+ find the following groups:
+
+ a[i]{read}, a[i+1]{read}, a[i+2]{write}
+ b[10]{read}, b[10]{write}
+ c[99 - i]{read}, c[i]{write}
+ d[i + 1]{read}, d[i]{write}
+
+ 2) Inside each of the group, we verify several conditions:
+ a) all the references must differ in indices only, and the indices
+ must all have the same step
+ b) the references must dominate loop latch (and thus, they must be
+ ordered by dominance relation).
+ c) the distance of the indices must be a small multiple of the step
+ We are then able to compute the difference of the references (# of
+ iterations before they point to the same place as the first of them).
+ Also, in case there are writes in the loop, we split the groups into
+ chains whose head is the write whose values are used by the reads in
+ the same chain. The chains are then processed independently,
+ making the further transformations simpler. Also, the shorter chains
+ need the same number of registers, but may require lower unrolling
+ factor in order to get rid of the copies on the loop latch.
+
+ In our example, we get the following chains (the chain for c is invalid).
+
+ a[i]{read,+0}, a[i+1]{read,-1}, a[i+2]{write,-2}
+ b[10]{read,+0}, b[10]{write,+0}
+ d[i + 1]{read,+0}, d[i]{write,+1}
+
+ 3) For each read, we determine the read or write whose value it reuses,
+ together with the distance of this reuse. I.e. we take the last
+ reference before it with distance 0, or the last of the references
+ with the smallest positive distance to the read. Then, we remove
+ the references that are not used in any of these chains, discard the
+ empty groups, and propagate all the links so that they point to the
+ single root reference of the chain (adjusting their distance
+ appropriately). Some extra care needs to be taken for references with
+ step 0. In our example (the numbers indicate the distance of the
+ reuse),
+
+ a[i] --> (*) 2, a[i+1] --> (*) 1, a[i+2] (*)
+ b[10] --> (*) 1, b[10] (*)
+
+ 4) The chains are combined together if possible. If the corresponding
+ elements of two chains are always combined together with the same
+ operator, we remember just the result of this combination, instead
+ of remembering the values separately. We may need to perform
+ reassociation to enable combining, for example
+
+ e[i] + f[i+1] + e[i+1] + f[i]
+
+ can be reassociated as
+
+ (e[i] + f[i]) + (e[i+1] + f[i+1])
+
+ and we can combine the chains for e and f into one chain.
+
+ 5) For each root reference (end of the chain) R, let N be maximum distance
+ of a reference reusing its value. Variables R0 upto RN are created,
+ together with phi nodes that transfer values from R1 .. RN to
+ R0 .. R(N-1).
+ Initial values are loaded to R0..R(N-1) (in case not all references
+ must necessarily be accessed and they may trap, we may fail here;
+ TODO sometimes, the loads could be guarded by a check for the number
+ of iterations). Values loaded/stored in roots are also copied to
+ RN. Other reads are replaced with the appropriate variable Ri.
+ Everything is put to SSA form.
+
+ As a small improvement, if R0 is dead after the root (i.e., all uses of
+ the value with the maximum distance dominate the root), we can avoid
+ creating RN and use R0 instead of it.
+
+ In our example, we get (only the parts concerning a and b are shown):
+ for (i = 0; i < 100; i++)
+ {
+ f = phi (a[0], s);
+ s = phi (a[1], f);
+ x = phi (b[10], x);
+
+ f = f + s;
+ a[i+2] = f;
+ x = x + i;
+ b[10] = x;
+ }
+
+ 6) Factor F for unrolling is determined as the smallest common multiple of
+ (N + 1) for each root reference (N for references for that we avoided
+ creating RN). If F and the loop is small enough, loop is unrolled F
+ times. The stores to RN (R0) in the copies of the loop body are
+ periodically replaced with R0, R1, ... (R1, R2, ...), so that they can
+ be coalesced and the copies can be eliminated.
+
+ TODO -- copy propagation and other optimizations may change the live
+ ranges of the temporary registers and prevent them from being coalesced;
+ this may increase the register pressure.
+
+ In our case, F = 2 and the (main loop of the) result is
+
+ for (i = 0; i < ...; i += 2)
+ {
+ f = phi (a[0], f);
+ s = phi (a[1], s);
+ x = phi (b[10], x);
+
+ f = f + s;
+ a[i+2] = f;
+ x = x + i;
+ b[10] = x;
+
+ s = s + f;
+ a[i+3] = s;
+ x = x + i;
+ b[10] = x;
+ }
+
+ TODO -- stores killing other stores can be taken into account, e.g.,
+ for (i = 0; i < n; i++)
+ {
+ a[i] = 1;
+ a[i+2] = 2;
+ }
+
+ can be replaced with
+
+ t0 = a[0];
+ t1 = a[1];
+ for (i = 0; i < n; i++)
+ {
+ a[i] = 1;
+ t2 = 2;
+ t0 = t1;
+ t1 = t2;
+ }
+ a[n] = t0;
+ a[n+1] = t1;
+
+ The interesting part is that this would generalize store motion; still, since
+ sm is performed elsewhere, it does not seem that important.
+
+ Predictive commoning can be generalized for arbitrary computations (not
+ just memory loads), and also nontrivial transfer functions (e.g., replacing
+ i * i with ii_last + 2 * i + 1), to generalize strength reduction. */
+
+ #include "config.h"
+ #include "system.h"
+ #include "coretypes.h"
+ #include "tm.h"
+ #include "tree.h"
+ #include "tm_p.h"
+ #include "cfgloop.h"
+ #include "tree-flow.h"
+ #include "ggc.h"
+ #include "tree-data-ref.h"
+ #include "tree-scalar-evolution.h"
+ #include "tree-chrec.h"
+ #include "params.h"
+ #include "diagnostic.h"
+ #include "tree-pass.h"
+ #include "tree-affine.h"
+ #include "tree-inline.h"
+
+ /* The maximum number of iterations between the considered memory
+ references. */
+
+ #define MAX_DISTANCE (target_avail_regs < 16 ? 4 : 8)
+
+ /* Data references. */
+
+ typedef struct dref
+ {
+ /* The reference itself. */
+ struct data_reference *ref;
+
+ /* The statement in that the reference appears. */
+ tree stmt;
+
+ /* Distance of the reference from the root of the chain (in number of
+ iterations of the loop). */
+ unsigned distance;
+
+ /* Number of iterations offset from the first reference in the component. */
+ double_int offset;
+
+ /* Number of the reference in a component, in dominance ordering. */
+ unsigned pos;
+
+ /* True if the memory reference is always accessed when the loop is
+ entered. */
+ unsigned always_accessed : 1;
+ } *dref;
+
+ DEF_VEC_P (dref);
+ DEF_VEC_ALLOC_P (dref, heap);
+
+ /* Type of the chain of the references. */
+
+ enum chain_type
+ {
+ /* The addresses of the references in the chain are constant. */
+ CT_INVARIANT,
+
+ /* There are only loads in the chain. */
+ CT_LOAD,
+
+ /* Root of the chain is store, the rest are loads. */
+ CT_STORE_LOAD,
+
+ /* A combination of two chains. */
+ CT_COMBINATION
+ };
+
+ /* Chains of data references. */
+
+ typedef struct chain
+ {
+ /* Type of the chain. */
+ enum chain_type type;
+
+ /* For combination chains, the operator and the two chains that are
+ combined, and the type of the result. */
+ enum tree_code operator;
+ tree rslt_type;
+ struct chain *ch1, *ch2;
+
+ /* The references in the chain. */
+ VEC(dref,heap) *refs;
+
+ /* The maximum distance of the reference in the chain from the root. */
+ unsigned length;
+
+ /* The variables used to copy the value throughout iterations. */
+ VEC(tree,heap) *vars;
+
+ /* Initializers for the variables. */
+ VEC(tree,heap) *inits;
+
+ /* True if there is a use of a variable with the maximal distance
+ that comes after the root in the loop. */
+ unsigned has_max_use_after : 1;
+
+ /* True if all the memory references in the chain are always accessed. */
+ unsigned all_always_accessed : 1;
+
+ /* True if this chain was combined together with some other chain. */
+ unsigned combined : 1;
+ } *chain_p;
+
+ DEF_VEC_P (chain_p);
+ DEF_VEC_ALLOC_P (chain_p, heap);
+
+ /* Describes the knowledge about the step of the memory references in
+ the component. */
+
+ enum ref_step_type
+ {
+ /* The step is zero. */
+ RS_INVARIANT,
+
+ /* The step is nonzero. */
+ RS_NONZERO,
+
+ /* The step may or may not be nonzero. */
+ RS_ANY
+ };
+
+ /* Components of the data dependence graph. */
+
+ struct component
+ {
+ /* The references in the component. */
+ VEC(dref,heap) *refs;
+
+ /* What we know about the step of the references in the component. */
+ enum ref_step_type comp_step;
+
+ /* Next component in the list. */
+ struct component *next;
+ };
+
+ /* Bitmap of ssa names defined by looparound phi nodes covered by chains. */
+
+ static bitmap looparound_phis;
+
+ /* Cache used by tree_to_aff_combination_expand. */
+
+ static struct pointer_map_t *name_expansions;
+
+ /* Dumps data reference REF to FILE. */
+
+ extern void dump_dref (FILE *, dref);
+ void
+ dump_dref (FILE *file, dref ref)
+ {
+ if (ref->ref)
+ {
+ fprintf (file, " ");
+ print_generic_expr (file, DR_REF (ref->ref), TDF_SLIM);
+ fprintf (file, " (id %u%s)\n", ref->pos,
+ DR_IS_READ (ref->ref) ? "" : ", write");
+
+ fprintf (file, " offset ");
+ dump_double_int (file, ref->offset, false);
+ fprintf (file, "\n");
+
+ fprintf (file, " distance %u\n", ref->distance);
+ }
+ else
+ {
+ if (TREE_CODE (ref->stmt) == PHI_NODE)
+ fprintf (file, " looparound ref\n");
+ else
+ fprintf (file, " combination ref\n");
+ fprintf (file, " in statement ");
+ print_generic_expr (file, ref->stmt, TDF_SLIM);
+ fprintf (file, "\n");
+ fprintf (file, " distance %u\n", ref->distance);
+ }
+
+ }
+
+ /* Dumps CHAIN to FILE. */
+
+ extern void dump_chain (FILE *, chain_p);
+ void
+ dump_chain (FILE *file, chain_p chain)
+ {
+ dref a;
+ const char *chain_type;
+ unsigned i;
+ tree var;
+
+ switch (chain->type)
+ {
+ case CT_INVARIANT:
+ chain_type = "Load motion";
+ break;
+
+ case CT_LOAD:
+ chain_type = "Loads-only";
+ break;
+
+ case CT_STORE_LOAD:
+ chain_type = "Store-loads";
+ break;
+
+ case CT_COMBINATION:
+ chain_type = "Combination";
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+
+ fprintf (file, "%s chain %p%s\n", chain_type, (void *) chain,
+ chain->combined ? " (combined)" : "");
+ if (chain->type != CT_INVARIANT)
+ fprintf (file, " max distance %u%s\n", chain->length,
+ chain->has_max_use_after ? "" : ", may reuse first");
+
+ if (chain->type == CT_COMBINATION)
+ {
+ fprintf (file, " equal to %p %s %p in type ",
+ (void *) chain->ch1, op_symbol_code (chain->operator),
+ (void *) chain->ch2);
+ print_generic_expr (file, chain->rslt_type, TDF_SLIM);
+ fprintf (file, "\n");
+ }
+
+ if (chain->vars)
+ {
+ fprintf (file, " vars");
+ for (i = 0; VEC_iterate (tree, chain->vars, i, var); i++)
+ {
+ fprintf (file, " ");
+ print_generic_expr (file, var, TDF_SLIM);
+ }
+ fprintf (file, "\n");
+ }
+
+ if (chain->inits)
+ {
+ fprintf (file, " inits");
+ for (i = 0; VEC_iterate (tree, chain->inits, i, var); i++)
+ {
+ fprintf (file, " ");
+ print_generic_expr (file, var, TDF_SLIM);
+ }
+ fprintf (file, "\n");
+ }
+
+ fprintf (file, " references:\n");
+ for (i = 0; VEC_iterate (dref, chain->refs, i, a); i++)
+ dump_dref (file, a);
+
+ fprintf (file, "\n");
+ }
+
+ /* Dumps CHAINS to FILE. */
+
+ extern void dump_chains (FILE *, VEC (chain_p, heap) *);
+ void
+ dump_chains (FILE *file, VEC (chain_p, heap) *chains)
+ {
+ chain_p chain;
+ unsigned i;
+
+ for (i = 0; VEC_iterate (chain_p, chains, i, chain); i++)
+ dump_chain (file, chain);
+ }
+
+ /* Dumps COMP to FILE. */
+
+ extern void dump_component (FILE *, struct component *);
+ void
+ dump_component (FILE *file, struct component *comp)
+ {
+ dref a;
+ unsigned i;
+
+ fprintf (file, "Component%s:\n",
+ comp->comp_step == RS_INVARIANT ? " (invariant)" : "");
+ for (i = 0; VEC_iterate (dref, comp->refs, i, a); i++)
+ dump_dref (file, a);
+ fprintf (file, "\n");
+ }
+
+ /* Dumps COMPS to FILE. */
+
+ extern void dump_components (FILE *, struct component *);
+ void
+ dump_components (FILE *file, struct component *comps)
+ {
+ struct component *comp;
+
+ for (comp = comps; comp; comp = comp->next)
+ dump_component (file, comp);
+ }
+
+ /* Frees a chain CHAIN. */
+
+ static void
+ release_chain (chain_p chain)
+ {
+ dref ref;
+ unsigned i;
+
+ if (chain == NULL)
+ return;
+
+ for (i = 0; VEC_iterate (dref, chain->refs, i, ref); i++)
+ free (ref);
+
+ VEC_free (dref, heap, chain->refs);
+ VEC_free (tree, heap, chain->vars);
+ VEC_free (tree, heap, chain->inits);
+
+ free (chain);
+ }
+
+ /* Frees CHAINS. */
+
+ static void
+ release_chains (VEC (chain_p, heap) *chains)
+ {
+ unsigned i;
+ chain_p chain;
+
+ for (i = 0; VEC_iterate (chain_p, chains, i, chain); i++)
+ release_chain (chain);
+ VEC_free (chain_p, heap, chains);
+ }
+
+ /* Frees a component COMP. */
+
+ static void
+ release_component (struct component *comp)
+ {
+ VEC_free (dref, heap, comp->refs);
+ free (comp);
+ }
+
+ /* Frees list of components COMPS. */
+
+ static void
+ release_components (struct component *comps)
+ {
+ struct component *act, *next;
+
+ for (act = comps; act; act = next)
+ {
+ next = act->next;
+ release_component (act);
+ }
+ }
+
+ /* Finds a root of tree given by FATHERS containing A, and performs path
+ shortening. */
+
+ static unsigned
+ component_of (unsigned fathers[], unsigned a)
+ {
+ unsigned root, n;
+
+ for (root = a; root != fathers[root]; root = fathers[root])
+ continue;
+
+ for (; a != root; a = n)
+ {
+ n = fathers[a];
+ fathers[a] = root;
+ }
+
+ return root;
+ }
+
+ /* Join operation for DFU. FATHERS gives the tree, SIZES are sizes of the
+ components, A and B are components to merge. */
+
+ static void
+ merge_comps (unsigned fathers[], unsigned sizes[], unsigned a, unsigned b)
+ {
+ unsigned ca = component_of (fathers, a);
+ unsigned cb = component_of (fathers, b);
+
+ if (ca == cb)
+ return;
+
+ if (sizes[ca] < sizes[cb])
+ {
+ sizes[cb] += sizes[ca];
+ fathers[ca] = cb;
+ }
+ else
+ {
+ sizes[ca] += sizes[cb];
+ fathers[cb] = ca;
+ }
+ }
+
+ /* Returns true if A is a reference that is suitable for predictive commoning
+ in the innermost loop that contains it. REF_STEP is set according to the
+ step of the reference A. */
+
+ static bool
+ suitable_reference_p (struct data_reference *a, enum ref_step_type *ref_step)
+ {
+ tree ref = DR_REF (a), step = DR_STEP (a);
+
+ if (!step
+ || !is_gimple_reg_type (TREE_TYPE (ref)))
+ return false;
+
+ if (integer_zerop (step))
+ *ref_step = RS_INVARIANT;
+ else if (integer_nonzerop (step))
+ *ref_step = RS_NONZERO;
+ else
+ *ref_step = RS_ANY;
+
+ return true;
+ }
+
+ /* Stores DR_OFFSET (DR) + DR_INIT (DR) to OFFSET. */
+
+ static void
+ aff_combination_dr_offset (struct data_reference *dr, aff_tree *offset)
+ {
+ aff_tree delta;
+
+ tree_to_aff_combination_expand (DR_OFFSET (dr), sizetype, offset,
+ &name_expansions);
+ aff_combination_const (&delta, sizetype, tree_to_double_int (DR_INIT (dr)));
+ aff_combination_add (offset, &delta);
+ }
+
+ /* Determines number of iterations of the innermost enclosing loop before B
+ refers to exactly the same location as A and stores it to OFF. If A and
+ B do not have the same step, they never meet, or anything else fails,
+ returns false, otherwise returns true. Both A and B are assumed to
+ satisfy suitable_reference_p. */
+
+ static bool
+ determine_offset (struct data_reference *a, struct data_reference *b,
+ double_int *off)
+ {
+ aff_tree diff, baseb, step;
+
+ /* Check whether the base address and the step of both references is the
+ same. */
+ if (!operand_equal_p (DR_STEP (a), DR_STEP (b), 0)
+ || !operand_equal_p (DR_BASE_ADDRESS (a), DR_BASE_ADDRESS (b), 0))
+ return false;
+
+ if (integer_zerop (DR_STEP (a)))
+ {
+ /* If the references have loop invariant address, check that they access
+ exactly the same location. */
+ *off = double_int_zero;
+ return (operand_equal_p (DR_OFFSET (a), DR_OFFSET (b), 0)
+ && operand_equal_p (DR_INIT (a), DR_INIT (b), 0));
+ }
+
+ /* Compare the offsets of the addresses, and check whether the difference
+ is a multiple of step. */
+ aff_combination_dr_offset (a, &diff);
+ aff_combination_dr_offset (b, &baseb);
+ aff_combination_scale (&baseb, double_int_minus_one);
+ aff_combination_add (&diff, &baseb);
+
+ tree_to_aff_combination_expand (DR_STEP (a), sizetype,
+ &step, &name_expansions);
+ return aff_combination_constant_multiple_p (&diff, &step, off);
+ }
+
+ /* Returns the last basic block in LOOP for that we are sure that
+ it is executed whenever the loop is entered. */
+
+ static basic_block
+ last_always_executed_block (struct loop *loop)
+ {
+ unsigned i;
+ VEC (edge, heap) *exits = get_loop_exit_edges (loop);
+ edge ex;
+ basic_block last = loop->latch;
+
+ for (i = 0; VEC_iterate (edge, exits, i, ex); i++)
+ last = nearest_common_dominator (CDI_DOMINATORS, last, ex->src);
+ VEC_free (edge, heap, exits);
+
+ return last;
+ }
+
+ /* Splits dependence graph on DATAREFS described by DEPENDS to components. */
+
+ static struct component *
+ split_data_refs_to_components (struct loop *loop,
+ VEC (data_reference_p, heap) *datarefs,
+ VEC (ddr_p, heap) *depends)
+ {
+ unsigned i, n = VEC_length (data_reference_p, datarefs);
+ unsigned ca, ia, ib, bad;
+ unsigned *comp_father = XNEWVEC (unsigned, n + 1);
+ unsigned *comp_size = XNEWVEC (unsigned, n + 1);
+ struct component **comps;
+ struct data_reference *dr, *dra, *drb;
+ struct data_dependence_relation *ddr;
+ struct component *comp_list = NULL, *comp;
+ dref dataref;
+ basic_block last_always_executed = last_always_executed_block (loop);
+
+ for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++)
+ {
+ if (!DR_REF (dr))
+ {
+ /* A fake reference for call or asm_expr that may clobber memory;
+ just fail. */
+ goto end;
+ }
+ dr->aux = i;
+ comp_father[i] = i;
+ comp_size[i] = 1;
+ }
+
+ /* A component reserved for the "bad" data references. */
+ comp_father[n] = n;
+ comp_size[n] = 1;
+
+ for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++)
+ {
+ enum ref_step_type dummy;
+
+ if (!suitable_reference_p (dr, &dummy))
+ {
+ ia = dr->aux;
+ merge_comps (comp_father, comp_size, n, ia);
+ }
+ }
+
+ for (i = 0; VEC_iterate (ddr_p, depends, i, ddr); i++)
+ {
+ double_int dummy_off;
+
+ if (DDR_ARE_DEPENDENT (ddr) == chrec_known)
+ continue;
+
+ dra = DDR_A (ddr);
+ drb = DDR_B (ddr);
+ ia = component_of (comp_father, dra->aux);
+ ib = component_of (comp_father, drb->aux);
+ if (ia == ib)
+ continue;
+
+ bad = component_of (comp_father, n);
+
+ /* If both A and B are reads, we may ignore unsuitable dependences. */
+ if (DR_IS_READ (dra) && DR_IS_READ (drb)
+ && (ia == bad || ib == bad
+ || !determine_offset (dra, drb, &dummy_off)))
+ continue;
+
+ merge_comps (comp_father, comp_size, ia, ib);
+ }
+
+ comps = XCNEWVEC (struct component *, n);
+ bad = component_of (comp_father, n);
+ for (i = 0; VEC_iterate (data_reference_p, datarefs, i, dr); i++)
+ {
+ ia = dr->aux;
+ ca = component_of (comp_father, ia);
+ if (ca == bad)
+ continue;
+
+ comp = comps[ca];
+ if (!comp)
+ {
+ comp = XCNEW (struct component);
+ comp->refs = VEC_alloc (dref, heap, comp_size[ca]);
+ comps[ca] = comp;
+ }
+
+ dataref = XCNEW (struct dref);
+ dataref->ref = dr;
+ dataref->stmt = DR_STMT (dr);
+ dataref->offset = double_int_zero;
+ dataref->distance = 0;
+
+ dataref->always_accessed
+ = dominated_by_p (CDI_DOMINATORS, last_always_executed,
+ bb_for_stmt (dataref->stmt));
+ dataref->pos = VEC_length (dref, comp->refs);
+ VEC_quick_push (dref, comp->refs, dataref);
+ }
+
+ for (i = 0; i < n; i++)
+ {
+ comp = comps[i];
+ if (comp)
+ {
+ comp->next = comp_list;
+ comp_list = comp;
+ }
+ }
+ free (comps);
+
+ end:
+ free (comp_father);
+ free (comp_size);
+ return comp_list;
+ }
+
+ /* Returns true if the component COMP satisfies the conditions
+ described in 2) at the begining of this file. LOOP is the current
+ loop. */
+
+ static bool
+ suitable_component_p (struct loop *loop, struct component *comp)
+ {
+ unsigned i;
+ dref a, first;
+ basic_block ba, bp = loop->header;
+ bool ok, has_write = false;
+
+ for (i = 0; VEC_iterate (dref, comp->refs, i, a); i++)
+ {
+ ba = bb_for_stmt (a->stmt);
+
+ if (!just_once_each_iteration_p (loop, ba))
+ return false;
+
+ gcc_assert (dominated_by_p (CDI_DOMINATORS, ba, bp));
+ bp = ba;
+
+ if (!DR_IS_READ (a->ref))
+ has_write = true;
+ }
+
+ first = VEC_index (dref, comp->refs, 0);
+ ok = suitable_reference_p (first->ref, &comp->comp_step);
+ gcc_assert (ok);
+ first->offset = double_int_zero;
+
+ for (i = 1; VEC_iterate (dref, comp->refs, i, a); i++)
+ {
+ if (!determine_offset (first->ref, a->ref, &a->offset))
+ return false;
+
+ #ifdef ENABLE_CHECKING
+ {
+ enum ref_step_type a_step;
+ ok = suitable_reference_p (a->ref, &a_step);
+ gcc_assert (ok && a_step == comp->comp_step);
+ }
+ #endif
+ }
+
+ /* If there is a write inside the component, we must know whether the
+ step is nonzero or not -- we would not otherwise be able to recognize
+ whether the value accessed by reads comes from the OFFSET-th iteration
+ or the previous one. */
+ if (has_write && comp->comp_step == RS_ANY)
+ return false;
+
+ return true;
+ }
+
+ /* Check the conditions on references inside each of components COMPS,
+ and remove the unsuitable components from the list. The new list
+ of components is returned. The conditions are described in 2) at
+ the begining of this file. LOOP is the current loop. */
+
+ static struct component *
+ filter_suitable_components (struct loop *loop, struct component *comps)
+ {
+ struct component **comp, *act;
+
+ for (comp = &comps; *comp; )
+ {
+ act = *comp;
+ if (suitable_component_p (loop, act))
+ comp = &act->next;
+ else
+ {
+ *comp = act->next;
+ release_component (act);
+ }
+ }
+
+ return comps;
+ }
+
+ /* Compares two drefs A and B by their offset and position. Callback for
+ qsort. */
+
+ static int
+ order_drefs (const void *a, const void *b)
+ {
+ const dref *da = a;
+ const dref *db = b;
+ int offcmp = double_int_scmp ((*da)->offset, (*db)->offset);
+
+ if (offcmp != 0)
+ return offcmp;
+
+ return (*da)->pos - (*db)->pos;
+ }
+
+ /* Returns root of the CHAIN. */
+
+ static inline dref
+ get_chain_root (chain_p chain)
+ {
+ return VEC_index (dref, chain->refs, 0);
+ }
+
+ /* Adds REF to the chain CHAIN. */
+
+ static void
+ add_ref_to_chain (chain_p chain, dref ref)
+ {
+ dref root = get_chain_root (chain);
+ double_int dist;
+
+ gcc_assert (double_int_scmp (root->offset, ref->offset) <= 0);
+ dist = double_int_add (ref->offset, double_int_neg (root->offset));
+ if (double_int_ucmp (uhwi_to_double_int (MAX_DISTANCE), dist) <= 0)
+ return;
+ gcc_assert (double_int_fits_in_uhwi_p (dist));
+
+ VEC_safe_push (dref, heap, chain->refs, ref);
+
+ ref->distance = double_int_to_uhwi (dist);
+
+ if (ref->distance >= chain->length)
+ {
+ chain->length = ref->distance;
+ chain->has_max_use_after = false;
+ }
+
+ if (ref->distance == chain->length
+ && ref->pos > root->pos)
+ chain->has_max_use_after = true;
+
+ chain->all_always_accessed &= ref->always_accessed;
+ }
+
+ /* Returns the chain for invariant component COMP. */
+
+ static chain_p
+ make_invariant_chain (struct component *comp)
+ {
+ chain_p chain = XCNEW (struct chain);
+ unsigned i;
+ dref ref;
+
+ chain->type = CT_INVARIANT;
+
+ chain->all_always_accessed = true;
+
+ for (i = 0; VEC_iterate (dref, comp->refs, i, ref); i++)
+ {
+ VEC_safe_push (dref, heap, chain->refs, ref);
+ chain->all_always_accessed &= ref->always_accessed;
+ }
+
+ return chain;
+ }
+
+ /* Make a new chain rooted at REF. */
+
+ static chain_p
+ make_rooted_chain (dref ref)
+ {
+ chain_p chain = XCNEW (struct chain);
+
+ chain->type = DR_IS_READ (ref->ref) ? CT_LOAD : CT_STORE_LOAD;
+
+ VEC_safe_push (dref, heap, chain->refs, ref);
+ chain->all_always_accessed = ref->always_accessed;
+
+ ref->distance = 0;
+
+ return chain;
+ }
+
+ /* Returns true if CHAIN is not trivial. */
+
+ static bool
+ nontrivial_chain_p (chain_p chain)
+ {
+ return chain != NULL && VEC_length (dref, chain->refs) > 1;
+ }
+
+ /* Returns the ssa name that contains the value of REF, or NULL_TREE if there
+ is no such name. */
+
+ static tree
+ name_for_ref (dref ref)
+ {
+ tree name;
+
+ if (TREE_CODE (ref->stmt) == GIMPLE_MODIFY_STMT)
+ {
+ if (!ref->ref || DR_IS_READ (ref->ref))
+ name = GIMPLE_STMT_OPERAND (ref->stmt, 0);
+ else
+ name = GIMPLE_STMT_OPERAND (ref->stmt, 1);
+ }
+ else
+ name = PHI_RESULT (ref->stmt);
+
+ return (TREE_CODE (name) == SSA_NAME ? name : NULL_TREE);
+ }
+
+ /* Returns true if REF is a valid initializer for ROOT with given DISTANCE (in
+ iterations of the innermost enclosing loop). */
+
+ static bool
+ valid_initializer_p (struct data_reference *ref,
+ unsigned distance, struct data_reference *root)
+ {
+ aff_tree diff, base, step;
+ double_int off;
+
+ if (!DR_BASE_ADDRESS (ref))
+ return false;
+
+ /* Both REF and ROOT must be accessing the same object. */
+ if (!operand_equal_p (DR_BASE_ADDRESS (ref), DR_BASE_ADDRESS (root), 0))
+ return false;
+
+ /* The initializer is defined outside of loop, hence its address must be
+ invariant inside the loop. */
+ gcc_assert (integer_zerop (DR_STEP (ref)));
+
+ /* If the address of the reference is invariant, initializer must access
+ exactly the same location. */
+ if (integer_zerop (DR_STEP (root)))
+ return (operand_equal_p (DR_OFFSET (ref), DR_OFFSET (root), 0)
+ && operand_equal_p (DR_INIT (ref), DR_INIT (root), 0));
+
+ /* Verify that this index of REF is equal to the root's index at
+ -DISTANCE-th iteration. */
+ aff_combination_dr_offset (root, &diff);
+ aff_combination_dr_offset (ref, &base);
+ aff_combination_scale (&base, double_int_minus_one);
+ aff_combination_add (&diff, &base);
+
+ tree_to_aff_combination_expand (DR_STEP (root), sizetype, &step,
+ &name_expansions);
+ if (!aff_combination_constant_multiple_p (&diff, &step, &off))
+ return false;
+
+ if (!double_int_equal_p (off, uhwi_to_double_int (distance)))
+ return false;
+
+ return true;
+ }
+
+ /* Finds looparound phi node of LOOP that copies the value of REF, and if its
+ initial value is correct (equal to initial value of REF shifted by one
+ iteration), returns the phi node. Otherwise, NULL_TREE is returned. ROOT
+ is the root of the current chain. */
+
+ static tree
+ find_looparound_phi (struct loop *loop, dref ref, dref root)
+ {
+ tree name, phi, init, init_stmt, init_ref;
+ edge latch = loop_latch_edge (loop);
+ struct data_reference init_dr;
+
+ if (TREE_CODE (ref->stmt) == GIMPLE_MODIFY_STMT)
+ {
+ if (DR_IS_READ (ref->ref))
+ name = GIMPLE_STMT_OPERAND (ref->stmt, 0);
+ else
+ name = GIMPLE_STMT_OPERAND (ref->stmt, 1);
+ }
+ else
+ name = PHI_RESULT (ref->stmt);
+ if (!name)
+ return NULL_TREE;
+
+ for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi))
+ if (PHI_ARG_DEF_FROM_EDGE (phi, latch) == name)
+ break;
+
+ if (!phi)
+ return NULL_TREE;
+
+ init = PHI_ARG_DEF_FROM_EDGE (phi, loop_preheader_edge (loop));
+ if (TREE_CODE (init) != SSA_NAME)
+ return NULL_TREE;
+ init_stmt = SSA_NAME_DEF_STMT (init);
+ if (TREE_CODE (init_stmt) != GIMPLE_MODIFY_STMT)
+ return NULL_TREE;
+ gcc_assert (GIMPLE_STMT_OPERAND (init_stmt, 0) == init);
+
+ init_ref = GIMPLE_STMT_OPERAND (init_stmt, 1);
+ if (!REFERENCE_CLASS_P (init_ref)
+ && !DECL_P (init_ref))
+ return NULL_TREE;
+
+ /* Analyze the behavior of INIT_REF with respect to LOOP (innermost
+ loop enclosing PHI). */
+ memset (&init_dr, 0, sizeof (struct data_reference));
+ DR_REF (&init_dr) = init_ref;
+ DR_STMT (&init_dr) = phi;
+ dr_analyze_innermost (&init_dr);
+
+ if (!valid_initializer_p (&init_dr, ref->distance + 1, root->ref))
+ return NULL_TREE;
+
+ return phi;
+ }
+
+ /* Adds a reference for the looparound copy of REF in PHI to CHAIN. */
+
+ static void
+ insert_looparound_copy (chain_p chain, dref ref, tree phi)
+ {
+ dref nw = XCNEW (struct dref), aref;
+ unsigned i;
+
+ nw->stmt = phi;
+ nw->distance = ref->distance + 1;
+ nw->always_accessed = 1;
+
+ for (i = 0; VEC_iterate (dref, chain->refs, i, aref); i++)
+ if (aref->distance >= nw->distance)
+ break;
+ VEC_safe_insert (dref, heap, chain->refs, i, nw);
+
+ if (nw->distance > chain->length)
+ {
+ chain->length = nw->distance;
+ chain->has_max_use_after = false;
+ }
+ }
+
+ /* For references in CHAIN that are copied around the LOOP (created previously
+ by PRE, or by user), add the results of such copies to the chain. This
+ enables us to remove the copies by unrolling, and may need less registers
+ (also, it may allow us to combine chains together). */
+
+ static void
+ add_looparound_copies (struct loop *loop, chain_p chain)
+ {
+ unsigned i;
+ dref ref, root = get_chain_root (chain);
+ tree phi;
+
+ for (i = 0; VEC_iterate (dref, chain->refs, i, ref); i++)
+ {
+ phi = find_looparound_phi (loop, ref, root);
+ if (!phi)
+ continue;
+
+ bitmap_set_bit (looparound_phis, SSA_NAME_VERSION (PHI_RESULT (phi)));
+ insert_looparound_copy (chain, ref, phi);
+ }
+ }
+
+ /* Find roots of the values and determine distances in the component COMP.
+ The references are redistributed into CHAINS. LOOP is the current
+ loop. */
+
+ static void
+ determine_roots_comp (struct loop *loop,
+ struct component *comp,
+ VEC (chain_p, heap) **chains)
+ {
+ unsigned i;
+ dref a;
+ chain_p chain = NULL;
+
+ /* Invariants are handled specially. */
+ if (comp->comp_step == RS_INVARIANT)
+ {
+ chain = make_invariant_chain (comp);
+ VEC_safe_push (chain_p, heap, *chains, chain);
+ return;
+ }
+
+ qsort (VEC_address (dref, comp->refs), VEC_length (dref, comp->refs),
+ sizeof (dref), order_drefs);
+
+ for (i = 0; VEC_iterate (dref, comp->refs, i, a); i++)
+ {
+ if (!chain || !DR_IS_READ (a->ref))
+ {
+ if (nontrivial_chain_p (chain))
+ VEC_safe_push (chain_p, heap, *chains, chain);
+ else
+ release_chain (chain);
+ chain = make_rooted_chain (a);
+ continue;
+ }
+
+ add_ref_to_chain (chain, a);
+ }
+
+ if (nontrivial_chain_p (chain))
+ {
+ add_looparound_copies (loop, chain);
+ VEC_safe_push (chain_p, heap, *chains, chain);
+ }
+ else
+ release_chain (chain);
+ }
+
+ /* Find roots of the values and determine distances in components COMPS, and
+ separates the references to CHAINS. LOOP is the current loop. */
+
+ static void
+ determine_roots (struct loop *loop,
+ struct component *comps, VEC (chain_p, heap) **chains)
+ {
+ struct component *comp;
+
+ for (comp = comps; comp; comp = comp->next)
+ determine_roots_comp (loop, comp, chains);
+ }
+
+ /* Replace the reference in statement STMT with temporary variable
+ NEW. If SET is true, NEW is instead initialized to the value of
+ the reference in the statement. IN_LHS is true if the reference
+ is in the lhs of STMT, false if it is in rhs. */
+
+ static void
+ replace_ref_with (tree stmt, tree new, bool set, bool in_lhs)
+ {
+ tree val, new_stmt;
+ block_stmt_iterator bsi;
+
+ if (TREE_CODE (stmt) == PHI_NODE)
+ {
+ gcc_assert (!in_lhs && !set);
+
+ val = PHI_RESULT (stmt);
+ bsi = bsi_after_labels (bb_for_stmt (stmt));
+ remove_phi_node (stmt, NULL_TREE, false);
+
+ /* Turn the phi node into GIMPLE_MODIFY_STMT. */
+ new_stmt = build_gimple_modify_stmt_stat (val, new);
+ SSA_NAME_DEF_STMT (val) = new_stmt;
+ bsi_insert_before (&bsi, new_stmt, BSI_NEW_STMT);
+ return;
+ }
+
+ /* Since the reference is of gimple_reg type, it should only
+ appear as lhs or rhs of modify statement. */
+ gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
+
+ /* If we do not need to initialize NEW, just replace the use of OLD. */
+ if (!set)
+ {
+ gcc_assert (!in_lhs);
+ GIMPLE_STMT_OPERAND (stmt, 1) = new;
+ update_stmt (stmt);
+ return;
+ }
+
+ bsi = bsi_for_stmt (stmt);
+ if (in_lhs)
+ {
+ val = GIMPLE_STMT_OPERAND (stmt, 1);
+
+ /* OLD = VAL
+
+ is transformed to
+
+ OLD = VAL
+ NEW = VAL
+
+ (since the reference is of gimple_reg type, VAL is either gimple
+ invariant or ssa name). */
+ }
+ else
+ {
+ val = GIMPLE_STMT_OPERAND (stmt, 0);
+
+ /* VAL = OLD
+
+ is transformed to
+
+ VAL = OLD
+ NEW = VAL */
+ }
+
+ new_stmt = build_gimple_modify_stmt_stat (new, unshare_expr (val));
+ bsi_insert_after (&bsi, new_stmt, BSI_NEW_STMT);
+ SSA_NAME_DEF_STMT (new) = new_stmt;
+ }
+
+ /* Returns the reference to the address of REF in the ITER-th iteration of
+ LOOP, or NULL if we fail to determine it (ITER may be negative). We
+ try to preserve the original shape of the reference (not rewrite it
+ as an indirect ref to the address), to make tree_could_trap_p in
+ prepare_initializers_chain return false more often. */
+
+ static tree
+ ref_at_iteration (struct loop *loop, tree ref, int iter)
+ {
+ tree idx, *idx_p, type, val, op0 = NULL_TREE, ret;
+ affine_iv iv;
+ bool ok;
+
+ if (handled_component_p (ref))
+ {
+ op0 = ref_at_iteration (loop, TREE_OPERAND (ref, 0), iter);
+ if (!op0)
+ return NULL_TREE;
+ }
+ else if (!INDIRECT_REF_P (ref))
+ return unshare_expr (ref);
+
+ if (TREE_CODE (ref) == INDIRECT_REF)
+ {
+ ret = build1 (INDIRECT_REF, TREE_TYPE (ref), NULL_TREE);
+ idx = TREE_OPERAND (ref, 0);
+ idx_p = &TREE_OPERAND (ret, 0);
+ }
+ else if (TREE_CODE (ref) == COMPONENT_REF)
+ {
+ /* Check that the offset is loop invariant. */
+ if (TREE_OPERAND (ref, 2)
+ && !expr_invariant_in_loop_p (loop, TREE_OPERAND (ref, 2)))
+ return NULL_TREE;
+
+ return build3 (COMPONENT_REF, TREE_TYPE (ref), op0,
+ unshare_expr (TREE_OPERAND (ref, 1)),
+ unshare_expr (TREE_OPERAND (ref, 2)));
+ }
+ else if (TREE_CODE (ref) == ARRAY_REF)
+ {
+ /* Check that the lower bound and the step are loop invariant. */
+ if (TREE_OPERAND (ref, 2)
+ && !expr_invariant_in_loop_p (loop, TREE_OPERAND (ref, 2)))
+ return NULL_TREE;
+ if (TREE_OPERAND (ref, 3)
+ && !expr_invariant_in_loop_p (loop, TREE_OPERAND (ref, 3)))
+ return NULL_TREE;
+
+ ret = build4 (ARRAY_REF, TREE_TYPE (ref), op0, NULL_TREE,
+ unshare_expr (TREE_OPERAND (ref, 2)),
+ unshare_expr (TREE_OPERAND (ref, 3)));
+ idx = TREE_OPERAND (ref, 1);
+ idx_p = &TREE_OPERAND (ret, 1);
+ }
+ else
+ return NULL_TREE;
+
+ ok = simple_iv (loop, first_stmt (loop->header), idx, &iv, true);
+ if (!ok)
+ return NULL_TREE;
+ iv.base = expand_simple_operations (iv.base);
+ if (integer_zerop (iv.step))
+ *idx_p = unshare_expr (iv.base);
+ else
+ {
+ type = TREE_TYPE (iv.base);
+ val = fold_build2 (MULT_EXPR, type, iv.step,
+ build_int_cst_type (type, iter));
+ val = fold_build2 (PLUS_EXPR, type, iv.base, val);
+ *idx_p = unshare_expr (val);
+ }
+
+ return ret;
+ }
+
+ /* Get the initialization expression for the INDEX-th temporary variable
+ of CHAIN. */
+
+ static tree
+ get_init_expr (chain_p chain, unsigned index)
+ {
+ if (chain->type == CT_COMBINATION)
+ {
+ tree e1 = get_init_expr (chain->ch1, index);
+ tree e2 = get_init_expr (chain->ch2, index);
+
+ return fold_build2 (chain->operator, chain->rslt_type, e1, e2);
+ }
+ else
+ return VEC_index (tree, chain->inits, index);
+ }
+
+ /* Marks all virtual operands of statement STMT for renaming. */
+
+ static void
+ mark_virtual_ops_for_renaming (tree stmt)
+ {
+ ssa_op_iter iter;
+ tree var;
+
+ if (TREE_CODE (stmt) == PHI_NODE)
+ return;
+
+ update_stmt (stmt);
+
+ FOR_EACH_SSA_TREE_OPERAND (var, stmt, iter, SSA_OP_ALL_VIRTUALS)
+ {
+ if (TREE_CODE (var) == SSA_NAME)
+ var = SSA_NAME_VAR (var);
+ mark_sym_for_renaming (var);
+ }
+ }
+
+ /* Calls mark_virtual_ops_for_renaming for all members of LIST. */
+
+ static void
+ mark_virtual_ops_for_renaming_list (tree list)
+ {
+ tree_stmt_iterator tsi;
+
+ for (tsi = tsi_start (list); !tsi_end_p (tsi); tsi_next (&tsi))
+ mark_virtual_ops_for_renaming (tsi_stmt (tsi));
+ }
+
+ /* Creates the variables for CHAIN, as well as phi nodes for them and
+ initialization on entry to LOOP. Uids of the newly created
+ temporary variables are marked in TMP_VARS. */
+
+ static void
+ initialize_root_vars (struct loop *loop, chain_p chain, bitmap tmp_vars)
+ {
+ unsigned i;
+ unsigned n = chain->length;
+ dref root = get_chain_root (chain);
+ bool reuse_first = !chain->has_max_use_after;
+ tree ref, init, var, next, stmts;
+ tree phi;
+ edge entry = loop_preheader_edge (loop), latch = loop_latch_edge (loop);
+
+ /* If N == 0, then all the references are within the single iteration. And
+ since this is an nonempty chain, reuse_first cannot be true. */
+ gcc_assert (n > 0 || !reuse_first);
+
+ chain->vars = VEC_alloc (tree, heap, n + 1);
+
+ if (chain->type == CT_COMBINATION)
+ ref = GIMPLE_STMT_OPERAND (root->stmt, 0);
+ else
+ ref = DR_REF (root->ref);
+
+ for (i = 0; i < n + (reuse_first ? 0 : 1); i++)
+ {
+ var = create_tmp_var (TREE_TYPE (ref), get_lsm_tmp_name (ref, i));
+ add_referenced_var (var);
+ bitmap_set_bit (tmp_vars, DECL_UID (var));
+ VEC_quick_push (tree, chain->vars, var);
+ }
+ if (reuse_first)
+ VEC_quick_push (tree, chain->vars, VEC_index (tree, chain->vars, 0));
+
+ for (i = 0; VEC_iterate (tree, chain->vars, i, var); i++)
+ VEC_replace (tree, chain->vars, i, make_ssa_name (var, NULL_TREE));
+
+ for (i = 0; i < n; i++)
+ {
+ var = VEC_index (tree, chain->vars, i);
+ next = VEC_index (tree, chain->vars, i + 1);
+ init = get_init_expr (chain, i);
+
+ init = force_gimple_operand (init, &stmts, true, NULL_TREE);
+ if (stmts)
+ {
+ mark_virtual_ops_for_renaming_list (stmts);
+ bsi_insert_on_edge_immediate (entry, stmts);
+ }
+
+ phi = create_phi_node (var, loop->header);
+ SSA_NAME_DEF_STMT (var) = phi;
+ add_phi_arg (phi, init, entry);
+ add_phi_arg (phi, next, latch);
+ }
+ }
+
+ /* Create the variables and initialization statement for root of chain
+ CHAIN. Uids of the newly created temporary variables are marked
+ in TMP_VARS. */
+
+ static void
+ initialize_root (struct loop *loop, chain_p chain, bitmap tmp_vars)
+ {
+ dref root = get_chain_root (chain);
+ bool in_lhs = (chain->type == CT_STORE_LOAD
+ || chain->type == CT_COMBINATION);
+
+ initialize_root_vars (loop, chain, tmp_vars);
+ replace_ref_with (root->stmt,
+ VEC_index (tree, chain->vars, chain->length),
+ true, in_lhs);
+ }
+
+ /* Initializes a variable for load motion for ROOT and prepares phi nodes and
+ initialization on entry to LOOP if necessary. The ssa name for the variable
+ is stored in VARS. If WRITTEN is true, also a phi node to copy its value
+ around the loop is created. Uid of the newly created temporary variable
+ is marked in TMP_VARS. INITS is the list containing the (single)
+ initializer. */
+
+ static void
+ initialize_root_vars_lm (struct loop *loop, dref root, bool written,
+ VEC(tree, heap) **vars, VEC(tree, heap) *inits,
+ bitmap tmp_vars)
+ {
+ unsigned i;
+ tree ref = DR_REF (root->ref), init, var, next, stmts;
+ tree phi;
+ edge entry = loop_preheader_edge (loop), latch = loop_latch_edge (loop);
+
+ /* Find the initializer for the variable, and check that it cannot
+ trap. */
+ init = VEC_index (tree, inits, 0);
+
+ *vars = VEC_alloc (tree, heap, written ? 2 : 1);
+ var = create_tmp_var (TREE_TYPE (ref), get_lsm_tmp_name (ref, 0));
+ add_referenced_var (var);
+ bitmap_set_bit (tmp_vars, DECL_UID (var));
+ VEC_quick_push (tree, *vars, var);
+ if (written)
+ VEC_quick_push (tree, *vars, VEC_index (tree, *vars, 0));
+
+ for (i = 0; VEC_iterate (tree, *vars, i, var); i++)
+ VEC_replace (tree, *vars, i, make_ssa_name (var, NULL_TREE));
+
+ var = VEC_index (tree, *vars, 0);
+
+ init = force_gimple_operand (init, &stmts, written, NULL_TREE);
+ if (stmts)
+ {
+ mark_virtual_ops_for_renaming_list (stmts);
+ bsi_insert_on_edge_immediate (entry, stmts);
+ }
+
+ if (written)
+ {
+ next = VEC_index (tree, *vars, 1);
+ phi = create_phi_node (var, loop->header);
+ SSA_NAME_DEF_STMT (var) = phi;
+ add_phi_arg (phi, init, entry);
+ add_phi_arg (phi, next, latch);
+ }
+ else
+ {
+ init = build_gimple_modify_stmt_stat (var, init);
+ SSA_NAME_DEF_STMT (var) = init;
+ mark_virtual_ops_for_renaming (init);
+ bsi_insert_on_edge_immediate (entry, init);
+ }
+ }
+
+
+ /* Execute load motion for references in chain CHAIN. Uids of the newly
+ created temporary variables are marked in TMP_VARS. */
+
+ static void
+ execute_load_motion (struct loop *loop, chain_p chain, bitmap tmp_vars)
+ {
+ VEC (tree, heap) *vars;
+ dref a;
+ unsigned n_writes = 0, ridx, i;
+ tree var;
+
+ gcc_assert (chain->type == CT_INVARIANT);
+ gcc_assert (!chain->combined);
+ for (i = 0; VEC_iterate (dref, chain->refs, i, a); i++)
+ if (!DR_IS_READ (a->ref))
+ n_writes++;
+
+ /* If there are no reads in the loop, there is nothing to do. */
+ if (n_writes == VEC_length (dref, chain->refs))
+ return;
+
+ initialize_root_vars_lm (loop, get_chain_root (chain), n_writes > 0,
+ &vars, chain->inits, tmp_vars);
+
+ ridx = 0;
+ for (i = 0; VEC_iterate (dref, chain->refs, i, a); i++)
+ {
+ bool is_read = DR_IS_READ (a->ref);
+ mark_virtual_ops_for_renaming (a->stmt);
+
+ if (!DR_IS_READ (a->ref))
+ {
+ n_writes--;
+ if (n_writes)
+ {
+ var = VEC_index (tree, vars, 0);
+ var = make_ssa_name (SSA_NAME_VAR (var), NULL_TREE);
+ VEC_replace (tree, vars, 0, var);
+ }
+ else
+ ridx = 1;
+ }
+
+ replace_ref_with (a->stmt, VEC_index (tree, vars, ridx),
+ !is_read, !is_read);
+ }
+
+ VEC_free (tree, heap, vars);
+ }
+
+ /* Returns the single statement in that NAME is used, excepting
+ the looparound phi nodes contained in one of the chains. If there is no
+ such statement, or more statements, NULL_TREE is returned. */
+
+ static tree
+ single_nonlooparound_use (tree name)
+ {
+ use_operand_p use;
+ imm_use_iterator it;
+ tree stmt, ret = NULL_TREE;
+
+ FOR_EACH_IMM_USE_FAST (use, it, name)
+ {
+ stmt = USE_STMT (use);
+
+ if (TREE_CODE (stmt) == PHI_NODE)
+ {
+ /* Ignore uses in looparound phi nodes. Uses in other phi nodes
+ could not be processed anyway, so just fail for them. */
+ if (bitmap_bit_p (looparound_phis,
+ SSA_NAME_VERSION (PHI_RESULT (stmt))))
+ continue;
+
+ return NULL_TREE;
+ }
+ else if (ret != NULL_TREE)
+ return NULL_TREE;
+ else
+ ret = stmt;
+ }
+
+ return ret;
+ }
+
+ /* Remove statement STMT, as well as the chain of assignments in that it is
+ used. */
+
+ static void
+ remove_stmt (tree stmt)
+ {
+ tree next, name;
+
+ if (TREE_CODE (stmt) == PHI_NODE)
+ {
+ name = PHI_RESULT (stmt);
+ next = single_nonlooparound_use (name);
+ remove_phi_node (stmt, NULL_TREE, true);
+
+ if (!next
+ || TREE_CODE (next) != GIMPLE_MODIFY_STMT
+ || GIMPLE_STMT_OPERAND (next, 1) != name)
+ return;
+
+ stmt = next;
+ }
+
+ while (1)
+ {
+ block_stmt_iterator bsi;
+
+ bsi = bsi_for_stmt (stmt);
+
+ name = GIMPLE_STMT_OPERAND (stmt, 0);
+ gcc_assert (TREE_CODE (name) == SSA_NAME);
+
+ next = single_nonlooparound_use (name);
+
+ mark_virtual_ops_for_renaming (stmt);
+ bsi_remove (&bsi, true);
+
+ if (!next
+ || TREE_CODE (next) != GIMPLE_MODIFY_STMT
+ || GIMPLE_STMT_OPERAND (next, 1) != name)
+ return;
+
+ stmt = next;
+ }
+ }
+
+ /* Perform the predictive commoning optimization for a chain CHAIN.
+ Uids of the newly created temporary variables are marked in TMP_VARS.*/
+
+ static void
+ execute_pred_commoning_chain (struct loop *loop, chain_p chain,
+ bitmap tmp_vars)
+ {
+ unsigned i;
+ dref a, root;
+ tree var;
+
+ if (chain->combined)
+ {
+ /* For combined chains, just remove the statements that are used to
+ compute the values of the expression (except for the root one). */
+ for (i = 1; VEC_iterate (dref, chain->refs, i, a); i++)
+ remove_stmt (a->stmt);
+ }
+ else
+ {
+ /* For non-combined chains, set up the variables that hold its value,
+ and replace the uses of the original references by these
+ variables. */
+ root = get_chain_root (chain);
+ mark_virtual_ops_for_renaming (root->stmt);
+
+ initialize_root (loop, chain, tmp_vars);
+ for (i = 1; VEC_iterate (dref, chain->refs, i, a); i++)
+ {
+ mark_virtual_ops_for_renaming (a->stmt);
+ var = VEC_index (tree, chain->vars, chain->length - a->distance);
+ replace_ref_with (a->stmt, var, false, false);
+ }
+ }
+ }
+
+ /* Determines the unroll factor necessary to remove as many temporary variable
+ copies as possible. CHAINS is the list of chains that will be
+ optimized. */
+
+ static unsigned
+ determine_unroll_factor (VEC (chain_p, heap) *chains)
+ {
+ chain_p chain;
+ unsigned factor = 1, af, nfactor, i;
+ unsigned max = PARAM_VALUE (PARAM_MAX_UNROLL_TIMES);
+
+ for (i = 0; VEC_iterate (chain_p, chains, i, chain); i++)
+ {
+ if (chain->type == CT_INVARIANT || chain->combined)
+ continue;
+
+ /* The best unroll factor for this chain is equal to the number of
+ temporary variables that we create for it. */
+ af = chain->length;
+ if (chain->has_max_use_after)
+ af++;
+
+ nfactor = factor * af / gcd (factor, af);
+ if (nfactor <= max)
+ factor = nfactor;
+ }
+
+ return factor;
+ }
+
+ /* Perform the predictive commoning optimization for CHAINS.
+ Uids of the newly created temporary variables are marked in TMP_VARS. */
+
+ static void
+ execute_pred_commoning (struct loop *loop, VEC (chain_p, heap) *chains,
+ bitmap tmp_vars)
+ {
+ chain_p chain;
+ unsigned i;
+
+ for (i = 0; VEC_iterate (chain_p, chains, i, chain); i++)
+ {
+ if (chain->type == CT_INVARIANT)
+ execute_load_motion (loop, chain, tmp_vars);
+ else
+ execute_pred_commoning_chain (loop, chain, tmp_vars);
+ }
+
+ update_ssa (TODO_update_ssa_only_virtuals);
+ }
+
+ /* For each reference in CHAINS, if its definining statement is
+ ssa name, set it to phi node that defines it. */
+
+ static void
+ replace_phis_by_defined_names (VEC (chain_p, heap) *chains)
+ {
+ chain_p chain;
+ dref a;
+ unsigned i, j;
+
+ for (i = 0; VEC_iterate (chain_p, chains, i, chain); i++)
+ for (j = 0; VEC_iterate (dref, chain->refs, j, a); j++)
+ {
+ gcc_assert (TREE_CODE (a->stmt) != SSA_NAME);
+ if (TREE_CODE (a->stmt) == PHI_NODE)
+ a->stmt = PHI_RESULT (a->stmt);
+ }
+ }
+
+ /* For each reference in CHAINS, if its definining statement is
+ phi node, set it to the ssa name that is defined by it. */
+
+ static void
+ replace_names_by_phis (VEC (chain_p, heap) *chains)
+ {
+ chain_p chain;
+ dref a;
+ unsigned i, j;
+
+ for (i = 0; VEC_iterate (chain_p, chains, i, chain); i++)
+ for (j = 0; VEC_iterate (dref, chain->refs, j, a); j++)
+ if (TREE_CODE (a->stmt) == SSA_NAME)
+ {
+ a->stmt = SSA_NAME_DEF_STMT (a->stmt);
+ gcc_assert (TREE_CODE (a->stmt) == PHI_NODE);
+ }
+ }
+
+ /* Wrapper over execute_pred_commoning, to pass it as a callback
+ to tree_transform_and_unroll_loop. */
+
+ struct epcc_data
+ {
+ VEC (chain_p, heap) *chains;
+ bitmap tmp_vars;
+ };
+
+ static void
+ execute_pred_commoning_cbck (struct loop *loop, void *data)
+ {
+ struct epcc_data *dta = data;
+
+ /* Restore phi nodes that were replaced by ssa names before
+ tree_transform_and_unroll_loop (see detailed description in
+ tree_predictive_commoning_loop). */
+ replace_names_by_phis (dta->chains);
+ execute_pred_commoning (loop, dta->chains, dta->tmp_vars);
+ }
+
+ /* Returns true if we can and should unroll LOOP FACTOR times. Number
+ of iterations of the loop is returned in NITER. */
+
+ static bool
+ should_unroll_loop_p (struct loop *loop, unsigned factor,
+ struct tree_niter_desc *niter)
+ {
+ edge exit;
+
+ if (factor == 1)
+ return false;
+
+ /* Check whether unrolling is possible. We only want to unroll loops
+ for that we are able to determine number of iterations. We also
+ want to split the extra iterations of the loop from its end,
+ therefore we require that the loop has precisely one
+ exit. */
+
+ exit = single_dom_exit (loop);
+ if (!exit)
+ return false;
+
+ if (!number_of_iterations_exit (loop, exit, niter, false))
+ return false;
+
+ /* And of course, we must be able to duplicate the loop. */
+ if (!can_duplicate_loop_p (loop))
+ return false;
+
+ /* The final loop should be small enough. */
+ if (tree_num_loop_insns (loop, &eni_size_weights) * factor
+ > (unsigned) PARAM_VALUE (PARAM_MAX_UNROLLED_INSNS))
+ return false;
+
+ return true;
+ }
+
+ /* Base NAME and all the names in the chain of phi nodes that use it
+ on variable VAR. The phi nodes are recognized by being in the copies of
+ the header of the LOOP. */
+
+ static void
+ base_names_in_chain_on (struct loop *loop, tree name, tree var)
+ {
+ tree stmt, phi;
+ imm_use_iterator iter;
+ edge e;
+
+ SSA_NAME_VAR (name) = var;
+
+ while (1)
+ {
+ phi = NULL;
+ FOR_EACH_IMM_USE_STMT (stmt, iter, name)
+ {
+ if (TREE_CODE (stmt) == PHI_NODE
+ && flow_bb_inside_loop_p (loop, bb_for_stmt (stmt)))
+ {
+ phi = stmt;
+ BREAK_FROM_IMM_USE_STMT (iter);
+ }
+ }
+ if (!phi)
+ return;
+
+ if (bb_for_stmt (phi) == loop->header)
+ e = loop_latch_edge (loop);
+ else
+ e = single_pred_edge (bb_for_stmt (stmt));
+
+ name = PHI_RESULT (phi);
+ SSA_NAME_VAR (name) = var;
+ }
+ }
+
+ /* Given an unrolled LOOP after predictive commoning, remove the
+ register copies arising from phi nodes by changing the base
+ variables of SSA names. TMP_VARS is the set of the temporary variables
+ for those we want to perform this. */
+
+ static void
+ eliminate_temp_copies (struct loop *loop, bitmap tmp_vars)
+ {
+ edge e;
+ tree phi, name, use, var, stmt;
+
+ e = loop_latch_edge (loop);
+ for (phi = phi_nodes (loop->header); phi; phi = PHI_CHAIN (phi))
+ {
+ name = PHI_RESULT (phi);
+ var = SSA_NAME_VAR (name);
+ if (!bitmap_bit_p (tmp_vars, DECL_UID (var)))
+ continue;
+ use = PHI_ARG_DEF_FROM_EDGE (phi, e);
+ gcc_assert (TREE_CODE (use) == SSA_NAME);
+
+ /* Base all the ssa names in the ud and du chain of NAME on VAR. */
+ stmt = SSA_NAME_DEF_STMT (use);
+ while (TREE_CODE (stmt) == PHI_NODE)
+ {
+ gcc_assert (single_pred_p (bb_for_stmt (stmt)));
+ use = PHI_ARG_DEF (stmt, 0);
+ stmt = SSA_NAME_DEF_STMT (use);
+ }
+
+ base_names_in_chain_on (loop, use, var);
+ }
+ }
+
+ /* Returns true if CHAIN is suitable to be combined. */
+
+ static bool
+ chain_can_be_combined_p (chain_p chain)
+ {
+ return (!chain->combined
+ && (chain->type == CT_LOAD || chain->type == CT_COMBINATION));
+ }
+
+ /* Returns the modify statement that uses NAME. Skips over assignment
+ statements, NAME is replaced with the actual name used in the returned
+ statement. */
+
+ static tree
+ find_use_stmt (tree *name)
+ {
+ tree stmt, rhs, lhs;
+
+ /* Skip over assignments. */
+ while (1)
+ {
+ stmt = single_nonlooparound_use (*name);
+ if (!stmt)
+ return NULL_TREE;
+
+ if (TREE_CODE (stmt) != GIMPLE_MODIFY_STMT)
+ return NULL_TREE;
+
+ lhs = GIMPLE_STMT_OPERAND (stmt, 0);
+ if (TREE_CODE (lhs) != SSA_NAME)
+ return NULL_TREE;
+
+ rhs = GIMPLE_STMT_OPERAND (stmt, 1);
+ if (rhs != *name)
+ break;
+
+ *name = lhs;
+ }
+
+ if (!EXPR_P (rhs)
+ || REFERENCE_CLASS_P (rhs)
+ || TREE_CODE_LENGTH (TREE_CODE (rhs)) != 2)
+ return NULL_TREE;
+
+ return stmt;
+ }
+
+ /* Returns true if we may perform reassociation for operation CODE in TYPE. */
+
+ static bool
+ may_reassociate_p (tree type, enum tree_code code)
+ {
+ if (FLOAT_TYPE_P (type)
+ && !flag_unsafe_math_optimizations)
+ return false;
+
+ return (commutative_tree_code (code)
+ && associative_tree_code (code));
+ }
+
+ /* If the operation used in STMT is associative and commutative, go through the
+ tree of the same operations and returns its root. Distance to the root
+ is stored in DISTANCE. */
+
+ static tree
+ find_associative_operation_root (tree stmt, unsigned *distance)
+ {
+ tree rhs = GIMPLE_STMT_OPERAND (stmt, 1), lhs, next;
+ enum tree_code code = TREE_CODE (rhs);
+ unsigned dist = 0;
+
+ if (!may_reassociate_p (TREE_TYPE (rhs), code))
+ return NULL_TREE;
+
+ while (1)
+ {
+ lhs = GIMPLE_STMT_OPERAND (stmt, 0);
+ gcc_assert (TREE_CODE (lhs) == SSA_NAME);
+
+ next = find_use_stmt (&lhs);
+ if (!next)
+ break;
+
+ rhs = GIMPLE_STMT_OPERAND (next, 1);
+ if (TREE_CODE (rhs) != code)
+ break;
+
+ stmt = next;
+ dist++;
+ }
+
+ if (distance)
+ *distance = dist;
+ return stmt;
+ }
+
+ /* Returns the common statement in that NAME1 and NAME2 have a use. If there
+ is no such statement, returns NULL_TREE. In case the operation used on
+ NAME1 and NAME2 is associative and comutative, returns the root of the
+ tree formed by this operation instead of the statement that uses NAME1 or
+ NAME2. */
+
+ static tree
+ find_common_use_stmt (tree *name1, tree *name2)
+ {
+ tree stmt1, stmt2;
+
+ stmt1 = find_use_stmt (name1);
+ if (!stmt1)
+ return NULL_TREE;
+
+ stmt2 = find_use_stmt (name2);
+ if (!stmt2)
+ return NULL_TREE;
+
+ if (stmt1 == stmt2)
+ return stmt1;
+
+ stmt1 = find_associative_operation_root (stmt1, NULL);
+ if (!stmt1)
+ return NULL_TREE;
+ stmt2 = find_associative_operation_root (stmt2, NULL);
+ if (!stmt2)
+ return NULL_TREE;
+
+ return (stmt1 == stmt2 ? stmt1 : NULL_TREE);
+ }
+
+ /* Checks whether R1 and R2 are combined together using CODE, with the result
+ in RSLT_TYPE, in order R1 CODE R2 if SWAP is false and in order R2 CODE R1
+ if it is true. If CODE is ERROR_MARK, set these values instead. */
+
+ static bool
+ combinable_refs_p (dref r1, dref r2,
+ enum tree_code *code, bool *swap, tree *rslt_type)
+ {
+ enum tree_code acode;
+ bool aswap;
+ tree atype;
+ tree name1, name2, stmt, rhs;
+
+ name1 = name_for_ref (r1);
+ name2 = name_for_ref (r2);
+ gcc_assert (name1 != NULL_TREE && name2 != NULL_TREE);
+
+ stmt = find_common_use_stmt (&name1, &name2);
+
+ if (!stmt)
+ return false;
+
+ rhs = GIMPLE_STMT_OPERAND (stmt, 1);
+ acode = TREE_CODE (rhs);
+ aswap = (!commutative_tree_code (acode)
+ && TREE_OPERAND (rhs, 0) != name1);
+ atype = TREE_TYPE (rhs);
+
+ if (*code == ERROR_MARK)
+ {
+ *code = acode;
+ *swap = aswap;
+ *rslt_type = atype;
+ return true;
+ }
+
+ return (*code == acode
+ && *swap == aswap
+ && *rslt_type == atype);
+ }
+
+ /* Remove OP from the operation on rhs of STMT, and replace STMT with
+ an assignment of the remaining operand. */
+
+ static void
+ remove_name_from_operation (tree stmt, tree op)
+ {
+ tree *rhs;
+
+ gcc_assert (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT);
+
+ rhs = &GIMPLE_STMT_OPERAND (stmt, 1);
+ if (TREE_OPERAND (*rhs, 0) == op)
+ *rhs = TREE_OPERAND (*rhs, 1);
+ else if (TREE_OPERAND (*rhs, 1) == op)
+ *rhs = TREE_OPERAND (*rhs, 0);
+ else
+ gcc_unreachable ();
+ update_stmt (stmt);
+ }
+
+ /* Reassociates the expression in that NAME1 and NAME2 are used so that they
+ are combined in a single statement, and returns this statement. */
+
+ static tree
+ reassociate_to_the_same_stmt (tree name1, tree name2)
+ {
+ tree stmt1, stmt2, root1, root2, r1, r2, s1, s2;
+ tree new_stmt, tmp_stmt, new_name, tmp_name, var;
+ unsigned dist1, dist2;
+ enum tree_code code;
+ tree type = TREE_TYPE (name1);
+ block_stmt_iterator bsi;
+
+ stmt1 = find_use_stmt (&name1);
+ stmt2 = find_use_stmt (&name2);
+ root1 = find_associative_operation_root (stmt1, &dist1);
+ root2 = find_associative_operation_root (stmt2, &dist2);
+ code = TREE_CODE (GIMPLE_STMT_OPERAND (stmt1, 1));
+
+ gcc_assert (root1 && root2 && root1 == root2
+ && code == TREE_CODE (GIMPLE_STMT_OPERAND (stmt2, 1)));
+
+ /* Find the root of the nearest expression in that both NAME1 and NAME2
+ are used. */
+ r1 = name1;
+ s1 = stmt1;
+ r2 = name2;
+ s2 = stmt2;
+
+ while (dist1 > dist2)
+ {
+ s1 = find_use_stmt (&r1);
+ r1 = GIMPLE_STMT_OPERAND (s1, 0);
+ dist1--;
+ }
+ while (dist2 > dist1)
+ {
+ s2 = find_use_stmt (&r2);
+ r2 = GIMPLE_STMT_OPERAND (s2, 0);
+ dist2--;
+ }
+
+ while (s1 != s2)
+ {
+ s1 = find_use_stmt (&r1);
+ r1 = GIMPLE_STMT_OPERAND (s1, 0);
+ s2 = find_use_stmt (&r2);
+ r2 = GIMPLE_STMT_OPERAND (s2, 0);
+ }
+
+ /* Remove NAME1 and NAME2 from the statements in that they are used
+ currently. */
+ remove_name_from_operation (stmt1, name1);
+ remove_name_from_operation (stmt2, name2);
+
+ /* Insert the new statement combining NAME1 and NAME2 before S1, and
+ combine it with the rhs of S1. */
+ var = create_tmp_var (type, "predreastmp");
+ add_referenced_var (var);
+ new_name = make_ssa_name (var, NULL_TREE);
+ new_stmt = build_gimple_modify_stmt_stat (new_name,
+ fold_build2 (code, type, name1, name2));
+ SSA_NAME_DEF_STMT (new_name) = new_stmt;
+
+ var = create_tmp_var (type, "predreastmp");
+ add_referenced_var (var);
+ tmp_name = make_ssa_name (var, NULL_TREE);
+ tmp_stmt = build_gimple_modify_stmt_stat (tmp_name,
+ GIMPLE_STMT_OPERAND (s1, 1));
+ SSA_NAME_DEF_STMT (tmp_name) = tmp_stmt;
+
+ GIMPLE_STMT_OPERAND (s1, 1) = fold_build2 (code, type, new_name, tmp_name);
+ update_stmt (s1);
+
+ bsi = bsi_for_stmt (s1);
+ bsi_insert_before (&bsi, new_stmt, BSI_SAME_STMT);
+ bsi_insert_before (&bsi, tmp_stmt, BSI_SAME_STMT);
+
+ return new_stmt;
+ }
+
+ /* Returns the statement that combines references R1 and R2. In case R1
+ and R2 are not used in the same statement, but they are used with an
+ associative and commutative operation in the same expression, reassociate
+ the expression so that they are used in the same statement. */
+
+ static tree
+ stmt_combining_refs (dref r1, dref r2)
+ {
+ tree stmt1, stmt2;
+ tree name1 = name_for_ref (r1);
+ tree name2 = name_for_ref (r2);
+
+ stmt1 = find_use_stmt (&name1);
+ stmt2 = find_use_stmt (&name2);
+ if (stmt1 == stmt2)
+ return stmt1;
+
+ return reassociate_to_the_same_stmt (name1, name2);
+ }
+
+ /* Tries to combine chains CH1 and CH2 together. If this succeeds, the
+ description of the new chain is returned, otherwise we return NULL. */
+
+ static chain_p
+ combine_chains (chain_p ch1, chain_p ch2)
+ {
+ dref r1, r2, nw;
+ enum tree_code op = ERROR_MARK;
+ bool swap = false;
+ chain_p new_chain;
+ unsigned i;
+ tree root_stmt;
+ tree rslt_type = NULL_TREE;
+
+ if (ch1 == ch2)
+ return false;
+ if (ch1->length != ch2->length)
+ return NULL;
+
+ if (VEC_length (dref, ch1->refs) != VEC_length (dref, ch2->refs))
+ return NULL;
+
+ for (i = 0; (VEC_iterate (dref, ch1->refs, i, r1)
+ && VEC_iterate (dref, ch2->refs, i, r2)); i++)
+ {
+ if (r1->distance != r2->distance)
+ return NULL;
+
+ if (!combinable_refs_p (r1, r2, &op, &swap, &rslt_type))
+ return NULL;
+ }
+
+ if (swap)
+ {
+ chain_p tmp = ch1;
+ ch1 = ch2;
+ ch2 = tmp;
+ }
+
+ new_chain = XCNEW (struct chain);
+ new_chain->type = CT_COMBINATION;
+ new_chain->operator = op;
+ new_chain->ch1 = ch1;
+ new_chain->ch2 = ch2;
+ new_chain->rslt_type = rslt_type;
+ new_chain->length = ch1->length;
+
+ for (i = 0; (VEC_iterate (dref, ch1->refs, i, r1)
+ && VEC_iterate (dref, ch2->refs, i, r2)); i++)
+ {
+ nw = XCNEW (struct dref);
+ nw->stmt = stmt_combining_refs (r1, r2);
+ nw->distance = r1->distance;
+
+ VEC_safe_push (dref, heap, new_chain->refs, nw);
+ }
+
+ new_chain->has_max_use_after = false;
+ root_stmt = get_chain_root (new_chain)->stmt;
+ for (i = 1; VEC_iterate (dref, new_chain->refs, i, nw); i++)
+ {
+ if (nw->distance == new_chain->length
+ && !stmt_dominates_stmt_p (nw->stmt, root_stmt))
+ {
+ new_chain->has_max_use_after = true;
+ break;
+ }
+ }
+
+ ch1->combined = true;
+ ch2->combined = true;
+ return new_chain;
+ }
+
+ /* Try to combine the CHAINS. */
+
+ static void
+ try_combine_chains (VEC (chain_p, heap) **chains)
+ {
+ unsigned i, j;
+ chain_p ch1, ch2, cch;
+ VEC (chain_p, heap) *worklist = NULL;
+
+ for (i = 0; VEC_iterate (chain_p, *chains, i, ch1); i++)
+ if (chain_can_be_combined_p (ch1))
+ VEC_safe_push (chain_p, heap, worklist, ch1);
+
+ while (!VEC_empty (chain_p, worklist))
+ {
+ ch1 = VEC_pop (chain_p, worklist);
+ if (!chain_can_be_combined_p (ch1))
+ continue;
+
+ for (j = 0; VEC_iterate (chain_p, *chains, j, ch2); j++)
+ {
+ if (!chain_can_be_combined_p (ch2))
+ continue;
+
+ cch = combine_chains (ch1, ch2);
+ if (cch)
+ {
+ VEC_safe_push (chain_p, heap, worklist, cch);
+ VEC_safe_push (chain_p, heap, *chains, cch);
+ break;
+ }
+ }
+ }
+ }
+
+ /* Sets alias information based on data reference DR for REF,
+ if necessary. */
+
+ static void
+ set_alias_info (tree ref, struct data_reference *dr)
+ {
+ tree var;
+ tree tag = DR_SYMBOL_TAG (dr);
+
+ gcc_assert (tag != NULL_TREE);
+
+ ref = get_base_address (ref);
+ if (!ref || !INDIRECT_REF_P (ref))
+ return;
+
+ var = SSA_NAME_VAR (TREE_OPERAND (ref, 0));
+ if (var_ann (var)->symbol_mem_tag)
+ return;
+
+ if (!MTAG_P (tag))
+ new_type_alias (var, tag, ref);
+ else
+ var_ann (var)->symbol_mem_tag = tag;
+
+ var_ann (var)->subvars = DR_SUBVARS (dr);
+ }
+
+ /* Prepare initializers for CHAIN in LOOP. Returns false if this is
+ impossible because one of these initializers may trap, true otherwise. */
+
+ static bool
+ prepare_initializers_chain (struct loop *loop, chain_p chain)
+ {
+ unsigned i, n = (chain->type == CT_INVARIANT) ? 1 : chain->length;
+ struct data_reference *dr = get_chain_root (chain)->ref;
+ tree init, stmts;
+ dref laref;
+ edge entry = loop_preheader_edge (loop);
+
+ /* Find the initializers for the variables, and check that they cannot
+ trap. */
+ chain->inits = VEC_alloc (tree, heap, n);
+ for (i = 0; i < n; i++)
+ VEC_quick_push (tree, chain->inits, NULL_TREE);
+
+ /* If we have replaced some looparound phi nodes, use their initializers
+ instead of creating our own. */
+ for (i = 0; VEC_iterate (dref, chain->refs, i, laref); i++)
+ {
+ if (TREE_CODE (laref->stmt) != PHI_NODE)
+ continue;
+
+ gcc_assert (laref->distance > 0);
+ VEC_replace (tree, chain->inits, n - laref->distance,
+ PHI_ARG_DEF_FROM_EDGE (laref->stmt, entry));
+ }
+
+ for (i = 0; i < n; i++)
+ {
+ if (VEC_index (tree, chain->inits, i) != NULL_TREE)
+ continue;
+
+ init = ref_at_iteration (loop, DR_REF (dr), (int) i - n);
+ if (!init)
+ return false;
+
+ if (!chain->all_always_accessed && tree_could_trap_p (init))
+ return false;
+
+ init = force_gimple_operand (init, &stmts, false, NULL_TREE);
+ if (stmts)
+ {
+ mark_virtual_ops_for_renaming_list (stmts);
+ bsi_insert_on_edge_immediate (entry, stmts);
+ }
+ set_alias_info (init, dr);
+
+ VEC_replace (tree, chain->inits, i, init);
+ }
+
+ return true;
+ }
+
+ /* Prepare initializers for CHAINS in LOOP, and free chains that cannot
+ be used because the initializers might trap. */
+
+ static void
+ prepare_initializers (struct loop *loop, VEC (chain_p, heap) *chains)
+ {
+ chain_p chain;
+ unsigned i;
+
+ for (i = 0; i < VEC_length (chain_p, chains); )
+ {
+ chain = VEC_index (chain_p, chains, i);
+ if (prepare_initializers_chain (loop, chain))
+ i++;
+ else
+ {
+ release_chain (chain);
+ VEC_unordered_remove (chain_p, chains, i);
+ }
+ }
+ }
+
+ /* Performs predictive commoning for LOOP. Returns true if LOOP was
+ unrolled. */
+
+ static bool
+ tree_predictive_commoning_loop (struct loop *loop)
+ {
+ VEC (data_reference_p, heap) *datarefs;
+ VEC (ddr_p, heap) *dependences;
+ struct component *components;
+ VEC (chain_p, heap) *chains = NULL;
+ unsigned unroll_factor;
+ struct tree_niter_desc desc;
+ bool unroll = false;
+ edge exit;
+ bitmap tmp_vars;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Processing loop %d\n", loop->num);
+
+ /* Find the data references and split them into components according to their
+ dependence relations. */
+ datarefs = VEC_alloc (data_reference_p, heap, 10);
+ dependences = VEC_alloc (ddr_p, heap, 10);
+ compute_data_dependences_for_loop (loop, true, &datarefs, &dependences);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ dump_data_dependence_relations (dump_file, dependences);
+
+ components = split_data_refs_to_components (loop, datarefs, dependences);
+ free_dependence_relations (dependences);
+ if (!components)
+ {
+ free_data_refs (datarefs);
+ return false;
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Initial state:\n\n");
+ dump_components (dump_file, components);
+ }
+
+ /* Find the suitable components and split them into chains. */
+ components = filter_suitable_components (loop, components);
+
+ tmp_vars = BITMAP_ALLOC (NULL);
+ looparound_phis = BITMAP_ALLOC (NULL);
+ determine_roots (loop, components, &chains);
+ release_components (components);
+
+ if (!chains)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "Predictive commoning failed: no suitable chains\n");
+ goto end;
+ }
+ prepare_initializers (loop, chains);
+
+ /* Try to combine the chains that are always worked with together. */
+ try_combine_chains (&chains);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Before commoning:\n\n");
+ dump_chains (dump_file, chains);
+ }
+
+ /* Determine the unroll factor, and if the loop should be unrolled, ensure
+ that its number of iterations is divisible by the factor. */
+ unroll_factor = determine_unroll_factor (chains);
+ scev_reset ();
+ unroll = should_unroll_loop_p (loop, unroll_factor, &desc);
+ exit = single_dom_exit (loop);
+
+ /* Execute the predictive commoning transformations, and possibly unroll the
+ loop. */
+ if (unroll)
+ {
+ struct epcc_data dta;
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Unrolling %u times.\n", unroll_factor);
+
+ dta.chains = chains;
+ dta.tmp_vars = tmp_vars;
+
+ update_ssa (TODO_update_ssa_only_virtuals);
+
+ /* Cfg manipulations performed in tree_transform_and_unroll_loop before
+ execute_pred_commoning_cbck is called may cause phi nodes to be
+ reallocated, which is a problem since CHAINS may point to these
+ statements. To fix this, we store the ssa names defined by the
+ phi nodes here instead of the phi nodes themselves, and restore
+ the phi nodes in execute_pred_commoning_cbck. A bit hacky. */
+ replace_phis_by_defined_names (chains);
+
+ tree_transform_and_unroll_loop (loop, unroll_factor, exit, &desc,
+ execute_pred_commoning_cbck, &dta);
+ eliminate_temp_copies (loop, tmp_vars);
+ }
+ else
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "Executing predictive commoning without unrolling.\n");
+ execute_pred_commoning (loop, chains, tmp_vars);
+ }
+
+ end: ;
+ release_chains (chains);
+ free_data_refs (datarefs);
+ BITMAP_FREE (tmp_vars);
+ BITMAP_FREE (looparound_phis);
+
+ free_affine_expand_cache (&name_expansions);
+
+ return unroll;
+ }
+
+ /* Runs predictive commoning. */
+
+ void
+ tree_predictive_commoning (void)
+ {
+ bool unrolled = false;
+ struct loop *loop;
+ loop_iterator li;
+
+ initialize_original_copy_tables ();
+ FOR_EACH_LOOP (li, loop, LI_ONLY_INNERMOST)
+ {
+ unrolled |= tree_predictive_commoning_loop (loop);
+ }
+
+ if (unrolled)
+ {
+ scev_reset ();
+ cleanup_tree_cfg_loop ();
+ }
+ free_original_copy_tables ();
+ }
Index: common.opt
===================================================================
*** common.opt (revision 124766)
--- common.opt (working copy)
*************** fpie
*** 719,724 ****
--- 719,728 ----
Common Report Var(flag_pie,1) VarExists
Generate position-independent code for executables if possible (small mode)
+ fpredictive-commoning
+ Common Report Var(flag_predictive_commoning)
+ Run predictive commoning optimization.
+
fprefetch-loop-arrays
Common Report Var(flag_prefetch_loop_arrays) Optimization
Generate prefetch instructions, if available, for arrays in loops
Index: tree-flow.h
===================================================================
*** tree-flow.h (revision 124766)
--- tree-flow.h (working copy)
*************** extern bool cleanup_tree_cfg_loop (void)
*** 786,791 ****
--- 786,792 ----
/* In tree-pretty-print.c. */
extern void dump_generic_bb (FILE *, basic_block, int, int);
+ extern const char *op_symbol_code (enum tree_code);
/* In tree-dfa.c */
extern var_ann_t create_var_ann (tree);
*************** unsigned int tree_unroll_loops_completel
*** 972,977 ****
--- 973,979 ----
unsigned int tree_ssa_prefetch_arrays (void);
unsigned int remove_empty_loops (void);
void tree_ssa_iv_optimize (void);
+ void tree_predictive_commoning (void);
bool number_of_iterations_exit (struct loop *, edge,
struct tree_niter_desc *niter, bool);
*************** void tree_transform_and_unroll_loop (str
*** 1017,1022 ****
--- 1019,1025 ----
edge, struct tree_niter_desc *,
transform_callback, void *);
bool contains_abnormal_ssa_name_p (tree);
+ bool stmt_dominates_stmt_p (tree, tree);
/* In tree-ssa-threadedge.c */
extern bool potentially_threadable_block (basic_block);
*************** enum move_pos
*** 1034,1039 ****
--- 1037,1043 ----
MOVE_POSSIBLE /* Unlimited movement. */
};
extern enum move_pos movement_possibility (tree);
+ char *get_lsm_tmp_name (tree, unsigned);
/* The reasons a variable may escape a function. */
enum escape_type
Index: Makefile.in
===================================================================
*** Makefile.in (revision 124766)
--- Makefile.in (working copy)
*************** OBJS-common = \
*** 1100,1105 ****
--- 1100,1106 ----
tree-optimize.o \
tree-outof-ssa.o \
tree-phinodes.o \
+ tree-predcom.o \
tree-pretty-print.o \
tree-profile.o \
tree-scalar-evolution.o \
*************** tree-ssa-loop-prefetch.o: tree-ssa-loop-
*** 2083,2096 ****
tree-pass.h $(GGC_H) $(RECOG_H) insn-config.h $(HASHTAB_H) $(SCEV_H) \
$(CFGLOOP_H) $(PARAMS_H) langhooks.h $(BASIC_BLOCK_H) hard-reg-set.h \
tree-chrec.h toplev.h langhooks.h $(TREE_INLINE_H)
tree-ssa-loop-ivopts.o : tree-ssa-loop-ivopts.c $(TREE_FLOW_H) $(CONFIG_H) \
$(SYSTEM_H) $(RTL_H) $(TREE_H) $(TM_P_H) $(CFGLOOP_H) $(EXPR_H) \
output.h $(DIAGNOSTIC_H) $(TIMEVAR_H) $(TM_H) coretypes.h $(TREE_DUMP_H) \
tree-pass.h $(GGC_H) $(RECOG_H) insn-config.h $(HASHTAB_H) $(SCEV_H) \
$(CFGLOOP_H) $(PARAMS_H) langhooks.h $(BASIC_BLOCK_H) hard-reg-set.h \
tree-chrec.h $(VARRAY_H) tree-affine.h pointer-set.h $(TARGET_H)
! tree-affine.o : tree-affine.c tree-affine.h $(CONFIG_H) \
! $(SYSTEM_H) $(RTL_H) $(TREE_H) $(TM_P_H) \
output.h $(DIAGNOSTIC_H) $(TM_H) coretypes.h $(TREE_DUMP_H)
tree-ssa-loop-manip.o : tree-ssa-loop-manip.c $(TREE_FLOW_H) $(CONFIG_H) \
$(SYSTEM_H) $(RTL_H) $(TREE_H) $(TM_P_H) $(CFGLOOP_H) \
--- 2084,2101 ----
tree-pass.h $(GGC_H) $(RECOG_H) insn-config.h $(HASHTAB_H) $(SCEV_H) \
$(CFGLOOP_H) $(PARAMS_H) langhooks.h $(BASIC_BLOCK_H) hard-reg-set.h \
tree-chrec.h toplev.h langhooks.h $(TREE_INLINE_H)
+ tree-predcom.o: tree-predcom.c $(CONFIG_H) $(SYSTEM_H) $(TREE_H) $(TM_P_H) \
+ $(CFGLOOP_H) $(TREE_FLOW_H) $(GGC_H) $(TREE_DATA_REF_H) $(SCEV_H) \
+ $(PARAMS_H) $(DIAGNOSTIC_H) tree-pass.h $(TM_H) coretypes.h tree-affine.h \
+ tree-inline.h
tree-ssa-loop-ivopts.o : tree-ssa-loop-ivopts.c $(TREE_FLOW_H) $(CONFIG_H) \
$(SYSTEM_H) $(RTL_H) $(TREE_H) $(TM_P_H) $(CFGLOOP_H) $(EXPR_H) \
output.h $(DIAGNOSTIC_H) $(TIMEVAR_H) $(TM_H) coretypes.h $(TREE_DUMP_H) \
tree-pass.h $(GGC_H) $(RECOG_H) insn-config.h $(HASHTAB_H) $(SCEV_H) \
$(CFGLOOP_H) $(PARAMS_H) langhooks.h $(BASIC_BLOCK_H) hard-reg-set.h \
tree-chrec.h $(VARRAY_H) tree-affine.h pointer-set.h $(TARGET_H)
! tree-affine.o : tree-affine.c tree-affine.h $(CONFIG_H) pointer-set.h \
! $(SYSTEM_H) $(RTL_H) $(TREE_H) $(TM_P_H) $(TREE_GIMPLE_H) \
output.h $(DIAGNOSTIC_H) $(TM_H) coretypes.h $(TREE_DUMP_H)
tree-ssa-loop-manip.o : tree-ssa-loop-manip.c $(TREE_FLOW_H) $(CONFIG_H) \
$(SYSTEM_H) $(RTL_H) $(TREE_H) $(TM_P_H) $(CFGLOOP_H) \
Index: passes.c
===================================================================
*** passes.c (revision 124766)
--- passes.c (working copy)
*************** init_optimization_passes (void)
*** 586,592 ****
--- 586,594 ----
struct tree_opt_pass **p = &pass_tree_loop.sub;
NEXT_PASS (pass_tree_loop_init);
NEXT_PASS (pass_copy_prop);
+ NEXT_PASS (pass_dce_loop);
NEXT_PASS (pass_lim);
+ NEXT_PASS (pass_predcom);
NEXT_PASS (pass_tree_unswitch);
NEXT_PASS (pass_scev_cprop);
NEXT_PASS (pass_empty_loop);
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