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Commit e9a8fc23 by Richard Biener Committed by Richard Biener
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params.def (PARAM_MAX_COMBINE_INSNS): New. 

2014-07-23  Richard Biener  <rguenther@suse.de>

	* params.def (PARAM_MAX_COMBINE_INSNS): New.
	* combine.c: Include statistics.h and params.h.
	(combine_instructions): Guard three and four insn combines
	with max-combine-insns value.  Record statistics for combines
	performed.
	* doc/invoke.texi (max-combine-insns): Document new param.

From-SVN: r212923
parent 322a0b39
Showing with 53 additions and 4 deletions
gcc/ChangeLog
2014-07-23 Richard Biener <rguenther@suse.de>
* params.def (PARAM_MAX_COMBINE_INSNS): New.
* combine.c: Include statistics.h and params.h.
(combine_instructions): Guard three and four insn combines
with max-combine-insns value. Record statistics for combines
performed.
* doc/invoke.texi (max-combine-insns): Document new param.
2014-07-23 Roman Gareev <gareevroman@gmail.com>
* graphite-isl-ast-to-gimple.c:
......
gcc/combine.c
......@@ -104,6 +104,8 @@ along with GCC; see the file COPYING3. If not see
#include "valtrack.h"
#include "cgraph.h"
#include "obstack.h"
#include "statistics.h"
#include "params.h"
/* Number of attempts to combine instructions in this function. */
......@@ -1209,6 +1211,7 @@ combine_instructions (rtx f, unsigned int nregs)
init_reg_last ();
setup_incoming_promotions (first);
last_bb = ENTRY_BLOCK_PTR_FOR_FN (cfun);
int max_combine = PARAM_VALUE (PARAM_MAX_COMBINE_INSNS);
FOR_EACH_BB_FN (this_basic_block, cfun)
{
......@@ -1229,8 +1232,9 @@ combine_instructions (rtx f, unsigned int nregs)
insn = next ? next : NEXT_INSN (insn))
{
next = 0;
if (NONDEBUG_INSN_P (insn))
{
if (!NONDEBUG_INSN_P (insn))
continue;
while (last_combined_insn
&& INSN_DELETED_P (last_combined_insn))
last_combined_insn = PREV_INSN (last_combined_insn);
......@@ -1255,10 +1259,14 @@ combine_instructions (rtx f, unsigned int nregs)
if ((next = try_combine (insn, links->insn, NULL_RTX,
NULL_RTX, &new_direct_jump_p,
last_combined_insn)) != 0)
{
statistics_counter_event (cfun, "two-insn combine", 1);
goto retry;
}
/* Try each sequence of three linked insns ending with this one. */
if (max_combine >= 3)
FOR_EACH_LOG_LINK (links, insn)
{
rtx link = links->insn;
......@@ -1272,8 +1280,11 @@ combine_instructions (rtx f, unsigned int nregs)
if ((next = try_combine (insn, link, nextlinks->insn,
NULL_RTX, &new_direct_jump_p,
last_combined_insn)) != 0)
{
statistics_counter_event (cfun, "three-insn combine", 1);
goto retry;
}
}
#ifdef HAVE_cc0
/* Try to combine a jump insn that uses CC0
......@@ -1338,6 +1349,7 @@ combine_instructions (rtx f, unsigned int nregs)
/* Try combining an insn with two different insns whose results it
uses. */
if (max_combine >= 3)
FOR_EACH_LOG_LINK (links, insn)
for (nextlinks = links->next; nextlinks;
nextlinks = nextlinks->next)
......@@ -1345,9 +1357,14 @@ combine_instructions (rtx f, unsigned int nregs)
nextlinks->insn, NULL_RTX,
&new_direct_jump_p,
last_combined_insn)) != 0)
{
statistics_counter_event (cfun, "three-insn combine", 1);
goto retry;
}
/* Try four-instruction combinations. */
if (max_combine >= 4)
FOR_EACH_LOG_LINK (links, insn)
{
struct insn_link *next1;
......@@ -1369,7 +1386,10 @@ combine_instructions (rtx f, unsigned int nregs)
nextlinks->insn,
&new_direct_jump_p,
last_combined_insn)) != 0)
{
statistics_counter_event (cfun, "four-insn combine", 1);
goto retry;
}
/* I0, I1 -> I2, I2 -> I3. */
for (nextlinks = next1->next; nextlinks;
nextlinks = nextlinks->next)
......@@ -1377,8 +1397,11 @@ combine_instructions (rtx f, unsigned int nregs)
nextlinks->insn,
&new_direct_jump_p,
last_combined_insn)) != 0)
{
statistics_counter_event (cfun, "four-insn combine", 1);
goto retry;
}
}
for (next1 = links->next; next1; next1 = next1->next)
{
......@@ -1391,16 +1414,22 @@ combine_instructions (rtx f, unsigned int nregs)
nextlinks->insn,
&new_direct_jump_p,
last_combined_insn)) != 0)
{
statistics_counter_event (cfun, "four-insn combine", 1);
goto retry;
}
/* I0 -> I1; I1, I2 -> I3. */
FOR_EACH_LOG_LINK (nextlinks, link1)
if ((next = try_combine (insn, link, link1,
nextlinks->insn,
&new_direct_jump_p,
last_combined_insn)) != 0)
{
statistics_counter_event (cfun, "four-insn combine", 1);
goto retry;
}
}
}
/* Try this insn with each REG_EQUAL note it links back to. */
FOR_EACH_LOG_LINK (links, insn)
......@@ -1430,7 +1459,10 @@ combine_instructions (rtx f, unsigned int nregs)
last_combined_insn);
i2mod = NULL_RTX;
if (next)
{
statistics_counter_event (cfun, "insn-with-note combine", 1);
goto retry;
}
SET_SRC (set) = orig;
}
}
......@@ -1438,11 +1470,10 @@ combine_instructions (rtx f, unsigned int nregs)
if (!NOTE_P (insn))
record_dead_and_set_regs (insn);
retry:
retry:
;
}
}
}
default_rtl_profile ();
clear_bb_flags ();
......
gcc/doc/invoke.texi
......@@ -10006,6 +10006,10 @@ The maximum size measured as number of RTLs that can be recorded in an expressio
in combiner for a pseudo register as last known value of that register. The default
is 10000.
@item max-combine-insns
The maximum number of instructions the RTL combiner tries to combine.
The default value is 2 at @option{-Og} and 4 otherwise.
@item integer-share-limit
Small integer constants can use a shared data structure, reducing the
compiler's memory usage and increasing its speed. This sets the maximum
......
gcc/params.def
......@@ -673,6 +673,11 @@ DEFPARAM(PARAM_MAX_LAST_VALUE_RTL,
"The maximum number of RTL nodes that can be recorded as combiner's last value",
10000, 0, 0)
DEFPARAM(PARAM_MAX_COMBINE_INSNS,
"max-combine-insns",
"The maximum number of insns combine tries to combine",
4, 2, 4)
/* INTEGER_CST nodes are shared for values [{-1,0} .. N) for
{signed,unsigned} integral types. This determines N.
Experimentation shows 251 to be a good value that generates the
......
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