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invoke.texi (max-loop-headers-insns): Document.

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* invoke.texi (max-loop-headers-insns): Document.
	* params.def (PARAM_MAX_LOOP_HEADER_INSNS): New.
	* tree-ssa-loop-ch.c (should_duplicate_loop_header_p): Update comment.
	(ch_base::copy_headers): Use PARAM_MAX_LOOP_HEADER_INSNS.

From-SVN: r237219
This commit is contained in:
Jan Hubicka 2016-06-08 16:11:51 +02:00 • committed by Jan Hubicka
parent b2ae281460
commit 568876dc70
4 changed files with 25 additions and 6 deletions
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7
gcc/ChangeLog
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@ -1,3 +1,10 @@
2016-06-07 Jan Hubicka <hubicka@ucw.cz>
* invoke.texi (max-loop-headers-insns): Document.
* params.def (PARAM_MAX_LOOP_HEADER_INSNS): New.
* tree-ssa-loop-ch.c (should_duplicate_loop_header_p): Update comment.
(ch_base::copy_headers): Use PARAM_MAX_LOOP_HEADER_INSNS.
2016-06-08 Richard Biener <rguenther@suse.de>
* tree-vect-stmts.c (vectorizable_load): Remove restrictions

4
gcc/doc/invoke.texi
View file

@ -9066,6 +9066,10 @@ The maximum number of insns of an unswitched loop.
@item max-unswitch-level
The maximum number of branches unswitched in a single loop.
@item max-loop-headers-insns
The maximum number of insns in loop header duplicated by he copy loop headers
pass.
@item lim-expensive
The minimum cost of an expensive expression in the loop invariant motion.

7
gcc/params.def
View file

@ -344,6 +344,13 @@ DEFPARAM(PARAM_MAX_UNSWITCH_LEVEL,
"The maximum number of unswitchings in a single loop.",
3, 0, 0)
/* The maximum number of insns in loop header duplicated by he copy loop
headers pass. */
DEFPARAM(PARAM_MAX_LOOP_HEADER_INSNS,
"max-loop-header-insns",
"The maximum number of insns in loop header duplicated by he copy loop headers pass.",
20, 0, 0)
/* The maximum number of iterations of a loop the brute force algorithm
for analysis of # of iterations of the loop tries to evaluate. */
DEFPARAM(PARAM_MAX_ITERATIONS_TO_TRACK,

13
gcc/tree-ssa-loop-ch.c
View file

@ -33,6 +33,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-inline.h"
#include "tree-ssa-scopedtables.h"
#include "tree-ssa-threadedge.h"
#include "params.h"
/* Duplicates headers of loops if they are small enough, so that the statements
in the loop body are always executed when the loop is entered. This
@ -106,8 +107,7 @@ should_duplicate_loop_header_p (basic_block header, struct loop *loop,
return false;
}
/* Approximately copy the conditions that used to be used in jump.c --
at most 20 insns and no calls. */
/* Count number of instructions and punt on calls. */
for (bsi = gsi_start_bb (header); !gsi_end_p (bsi); gsi_next (&bsi))
{
last = gsi_stmt (bsi);
@ -290,8 +290,8 @@ ch_base::copy_headers (function *fun)
FOR_EACH_LOOP (loop, 0)
{
/* Copy at most 20 insns. */
int limit = 20;
int initial_limit = PARAM_VALUE (PARAM_MAX_LOOP_HEADER_INSNS);
int remaining_limit = initial_limit;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file,
"Analyzing loop %i\n", loop->num);
@ -313,7 +313,7 @@ ch_base::copy_headers (function *fun)
exit = NULL;
n_bbs = 0;
while (should_duplicate_loop_header_p (header, loop, &limit))
while (should_duplicate_loop_header_p (header, loop, &remaining_limit))
{
/* Find a successor of header that is inside a loop; i.e. the new
header after the condition is copied. */
@ -333,7 +333,8 @@ ch_base::copy_headers (function *fun)
fprintf (dump_file,
"Duplicating header of the loop %d up to edge %d->%d,"
" %i insns.\n",
loop->num, exit->src->index, exit->dest->index, 20 - limit);
loop->num, exit->src->index, exit->dest->index,
initial_limit - remaining_limit);
/* Ensure that the header will have just the latch as a predecessor
inside the loop. */