mirror of
https://gcc.gnu.org/git/gcc.git
synced 2024-12-03 16:54:27 +08:00
gcse.c (is_too_expensive): New function.
* gcse.c (is_too_expensive): New function. (gcse_main, delete_null_pointer_checks, bypass_jumps): Use it. From-SVN: r70801
This commit is contained in:
Nathan Sidwell
Nathan Sidwell
parent
7e2055ec11
commit
d128effb32
@ -1,3 +1,8 @@
|
||||
2003-08-26 Nathan Sidwell <nathan@codesourcery.com>
|
||||
|
||||
* gcse.c (is_too_expensive): New function.
|
||||
(gcse_main, delete_null_pointer_checks, bypass_jumps): Use it.
|
||||
|
||||
2003-08-25 Zack Weinberg <zack@codesourcery.com>
|
||||
|
||||
* config.gcc (hppa*-*-hpux11*, ia64*-*-hpux*): Remove
|
||||
|
||||
131
gcc/gcse.c
131
gcc/gcse.c
@ -165,7 +165,7 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
|
||||
#include "ggc.h"
|
||||
#include "params.h"
|
||||
#include "cselib.h"
|
||||
|
||||
#include "intl.h"
|
||||
#include "obstack.h"
|
||||
|
||||
/* Propagate flow information through back edges and thus enable PRE's
|
||||
@ -703,7 +703,9 @@ static void local_cprop_find_used_regs (rtx *, void *);
|
||||
static bool do_local_cprop (rtx, rtx, int, rtx*);
|
||||
static bool adjust_libcall_notes (rtx, rtx, rtx, rtx*);
|
||||
static void local_cprop_pass (int);
|
||||
static bool is_too_expensive (const char *);
|
||||
|
||||
|
||||
/* Entry point for global common subexpression elimination.
|
||||
F is the first instruction in the function. */
|
||||
|
||||
@ -737,39 +739,10 @@ gcse_main (rtx f, FILE *file)
|
||||
if (file)
|
||||
dump_flow_info (file);
|
||||
|
||||
/* Return if there's nothing to do. */
|
||||
if (n_basic_blocks <= 1)
|
||||
/* Return if there's nothing to do, or it is too expensive. */
|
||||
if (n_basic_blocks <= 1 || is_too_expensive (_("GCSE disabled")))
|
||||
return 0;
|
||||
|
||||
/* Trying to perform global optimizations on flow graphs which have
|
||||
a high connectivity will take a long time and is unlikely to be
|
||||
particularly useful.
|
||||
|
||||
In normal circumstances a cfg should have about twice as many edges
|
||||
as blocks. But we do not want to punish small functions which have
|
||||
a couple switch statements. So we require a relatively large number
|
||||
of basic blocks and the ratio of edges to blocks to be high. */
|
||||
if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20)
|
||||
{
|
||||
if (warn_disabled_optimization)
|
||||
warning ("GCSE disabled: %d > 1000 basic blocks and %d >= 20 edges/basic block",
|
||||
n_basic_blocks, n_edges / n_basic_blocks);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* If allocating memory for the cprop bitmap would take up too much
|
||||
storage it's better just to disable the optimization. */
|
||||
if ((n_basic_blocks
|
||||
* SBITMAP_SET_SIZE (max_gcse_regno)
|
||||
* sizeof (SBITMAP_ELT_TYPE)) > MAX_GCSE_MEMORY)
|
||||
{
|
||||
if (warn_disabled_optimization)
|
||||
warning ("GCSE disabled: %d basic blocks and %d registers",
|
||||
n_basic_blocks, max_gcse_regno);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
||||
gcc_obstack_init (&gcse_obstack);
|
||||
bytes_used = 0;
|
||||
|
||||
@ -5945,28 +5918,17 @@ delete_null_pointer_checks (rtx f ATTRIBUTE_UNUSED)
|
||||
basic_block bb;
|
||||
int reg;
|
||||
int regs_per_pass;
|
||||
int max_reg;
|
||||
int max_reg = max_reg_num ();
|
||||
struct null_pointer_info npi;
|
||||
int something_changed = 0;
|
||||
|
||||
/* If we have only a single block, then there's nothing to do. */
|
||||
if (n_basic_blocks <= 1)
|
||||
return 0;
|
||||
|
||||
/* Trying to perform global optimizations on flow graphs which have
|
||||
a high connectivity will take a long time and is unlikely to be
|
||||
particularly useful.
|
||||
|
||||
In normal circumstances a cfg should have about twice as many edges
|
||||
as blocks. But we do not want to punish small functions which have
|
||||
a couple switch statements. So we require a relatively large number
|
||||
of basic blocks and the ratio of edges to blocks to be high. */
|
||||
if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20)
|
||||
/* If we have only a single block, or it is too expensive, give up. */
|
||||
if (n_basic_blocks <= 1
|
||||
|| is_too_expensive (_ ("NULL pointer checks disabled")))
|
||||
return 0;
|
||||
|
||||
/* We need four bitmaps, each with a bit for each register in each
|
||||
basic block. */
|
||||
max_reg = max_reg_num ();
|
||||
regs_per_pass = get_bitmap_width (4, last_basic_block, max_reg);
|
||||
|
||||
/* Allocate bitmaps to hold local and global properties. */
|
||||
@ -7704,39 +7666,10 @@ bypass_jumps (FILE *file)
|
||||
if (file)
|
||||
dump_flow_info (file);
|
||||
|
||||
/* Return if there's nothing to do. */
|
||||
if (n_basic_blocks <= 1)
|
||||
/* Return if there's nothing to do, or it is too expensive */
|
||||
if (n_basic_blocks <= 1 || is_too_expensive (_ ("jump bypassing disabled")))
|
||||
return 0;
|
||||
|
||||
/* Trying to perform global optimizations on flow graphs which have
|
||||
a high connectivity will take a long time and is unlikely to be
|
||||
particularly useful.
|
||||
|
||||
In normal circumstances a cfg should have about twice as many edges
|
||||
as blocks. But we do not want to punish small functions which have
|
||||
a couple switch statements. So we require a relatively large number
|
||||
of basic blocks and the ratio of edges to blocks to be high. */
|
||||
if (n_basic_blocks > 1000 && n_edges / n_basic_blocks >= 20)
|
||||
{
|
||||
if (warn_disabled_optimization)
|
||||
warning ("BYPASS disabled: %d > 1000 basic blocks and %d >= 20 edges/basic block",
|
||||
n_basic_blocks, n_edges / n_basic_blocks);
|
||||
return 0;
|
||||
}
|
||||
|
||||
/* If allocating memory for the cprop bitmap would take up too much
|
||||
storage it's better just to disable the optimization. */
|
||||
if ((n_basic_blocks
|
||||
* SBITMAP_SET_SIZE (max_gcse_regno)
|
||||
* sizeof (SBITMAP_ELT_TYPE)) > MAX_GCSE_MEMORY)
|
||||
{
|
||||
if (warn_disabled_optimization)
|
||||
warning ("GCSE disabled: %d basic blocks and %d registers",
|
||||
n_basic_blocks, max_gcse_regno);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
gcc_obstack_init (&gcse_obstack);
|
||||
bytes_used = 0;
|
||||
|
||||
@ -7777,4 +7710,44 @@ bypass_jumps (FILE *file)
|
||||
return changed;
|
||||
}
|
||||
|
||||
/* Return true if the graph is too expensive to optimize. PASS is the
|
||||
optimization about to be performed. */
|
||||
|
||||
static bool
|
||||
is_too_expensive (const char *pass)
|
||||
{
|
||||
/* Trying to perform global optimizations on flow graphs which have
|
||||
a high connectivity will take a long time and is unlikely to be
|
||||
particularly useful.
|
||||
|
||||
In normal circumstances a cfg should have about twice as many
|
||||
edges as blocks. But we do not want to punish small functions
|
||||
which have a couple switch statements. Rather than simply
|
||||
threshold the number of blocks, uses something with a more
|
||||
graceful degradation. */
|
||||
if (n_edges > 20000 + n_basic_blocks * 4)
|
||||
{
|
||||
if (warn_disabled_optimization)
|
||||
warning ("%s: %d basic blocks and %d edges/basic block",
|
||||
pass, n_basic_blocks, n_edges / n_basic_blocks);
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/* If allocating memory for the cprop bitmap would take up too much
|
||||
storage it's better just to disable the optimization. */
|
||||
if ((n_basic_blocks
|
||||
* SBITMAP_SET_SIZE (max_reg_num ())
|
||||
* sizeof (SBITMAP_ELT_TYPE)) > MAX_GCSE_MEMORY)
|
||||
{
|
||||
if (warn_disabled_optimization)
|
||||
warning ("%s: %d basic blocks and %d registers",
|
||||
pass, n_basic_blocks, max_reg_num ());
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
#include "gt-gcse.h"
|
||||
|
||||
Loading…
Reference in New Issue
Block a user