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re PR tree-optimization/77445 (Performance drop after r239219 on coremark test)

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PR middle-end/77445
	* gcc.dg/tree-ssa/pr77445-2.c: Update testcase to check that all
	threading is done.
	* tree-ssa-threadbackward.c (profitable_jump_thread_path): Dump
	statistics of the analyzed path; allow threading for speed when
	any of BBs along the path are optimized for speed.

From-SVN: r245135
This commit is contained in:
Jan Hubicka 2017-02-02 21:22:13 +01:00 • committed by Jan Hubicka
parent b47507fe99
commit 0f0c2cc3a1
4 changed files with 42 additions and 4 deletions
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7
gcc/ChangeLog
View file

@ -1,3 +1,10 @@
2017-02-02 Jan Hubicka <hubicka@ucw.cz>
PR middle-end/77445
* tree-ssa-threadbackward.c (profitable_jump_thread_path): Dump
statistics of the analyzed path; allow threading for speed when
any of BBs along the path are optimized for speed.
2017-02-02 Eric Botcazou <ebotcazou@adacore.com>
PR middle-end/78468

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2017-02-02 Jan Hubicka <hubicka@ucw.cz>
PR middle-end/77445
* gcc.dg/tree-ssa/pr77445-2.c: Update testcase to check that all
threading is done.
2017-02-02 Tamar Christina <tamar.christina@arm.com>
PR middle-end/78142

6
gcc/testsuite/gcc.dg/tree-ssa/pr77445-2.c
View file

@ -1,5 +1,5 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-tree-thread1-details-blocks-stats" } */
/* { dg-options "-O2 -fdump-tree-thread-details-blocks-stats" } */
typedef enum STATES {
START=0,
INVALID,
@ -121,3 +121,7 @@ enum STATES FMS( u8 **in , u32 *transitions) {
increase much. */
/* { dg-final { scan-tree-dump "Jumps threaded: 1\[1-9\]" "thread1" } } */
/* { dg-final { scan-tree-dump-times "Invalid sum" 2 "thread1" } } */
/* { dg-final { scan-tree-dump-not "not considered" "thread1" } } */
/* { dg-final { scan-tree-dump-not "not considered" "thread2" } } */
/* { dg-final { scan-tree-dump-not "not considered" "thread3" } } */
/* { dg-final { scan-tree-dump-not "not considered" "thread4" } } */

27
gcc/tree-ssa-threadbackward.c
View file

@ -159,6 +159,10 @@ profitable_jump_thread_path (vec<basic_block, va_gc> *&path,
bool threaded_through_latch = false;
bool multiway_branch_in_path = false;
bool threaded_multiway_branch = false;
bool contains_hot_bb = false;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Checking profitability of path (backwards): ");
/* Count the number of instructions on the path: as these instructions
will have to be duplicated, we will not record the path if there
@ -168,6 +172,8 @@ profitable_jump_thread_path (vec<basic_block, va_gc> *&path,
{
basic_block bb = (*path)[j];
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " bb:%i", bb->index);
/* Remember, blocks in the path are stored in opposite order
in the PATH array. The last entry in the array represents
the block with an outgoing edge that we will redirect to the
@ -177,6 +183,7 @@ profitable_jump_thread_path (vec<basic_block, va_gc> *&path,
branch. */
if (j < path_length - 1)
{
int orig_n_insns = n_insns;
if (bb->loop_father != loop)
{
path_crosses_loops = true;
@ -219,6 +226,8 @@ profitable_jump_thread_path (vec<basic_block, va_gc> *&path,
}
}
if (!contains_hot_bb && speed_p)
contains_hot_bb |= optimize_bb_for_speed_p (bb);
for (gsi = gsi_after_labels (bb);
!gsi_end_p (gsi);
gsi_next_nondebug (&gsi))
@ -229,8 +238,10 @@ profitable_jump_thread_path (vec<basic_block, va_gc> *&path,
&& !(gimple_code (stmt) == GIMPLE_ASSIGN
&& gimple_assign_rhs_code (stmt) == ASSERT_EXPR)
&& !is_gimple_debug (stmt))
n_insns += estimate_num_insns (stmt, &eni_size_weights);
n_insns += estimate_num_insns (stmt, &eni_size_weights);
}
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " (%i insns)", n_insns-orig_n_insns);
/* We do not look at the block with the threaded branch
in this loop. So if any block with a last statement that
@ -264,7 +275,13 @@ profitable_jump_thread_path (vec<basic_block, va_gc> *&path,
last block in the threading path. So don't count it against our
statement count. */
n_insns-= estimate_num_insns (stmt, &eni_size_weights);
int stmt_insns = estimate_num_insns (stmt, &eni_size_weights);
n_insns-= stmt_insns;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "\n Control statement insns: %i\n"
" Overall: %i insns\n",
stmt_insns, n_insns);
/* We have found a constant value for ARG. For GIMPLE_SWITCH
and GIMPLE_GOTO, we use it as-is. However, for a GIMPLE_COND
@ -311,7 +328,11 @@ profitable_jump_thread_path (vec<basic_block, va_gc> *&path,
return NULL;
}
if (speed_p && optimize_edge_for_speed_p (taken_edge))
/* Threading is profitable if the path duplicated is hot but also
in a case we separate cold path from hot path and permit optimization
of the hot path later. Be on the agressive side here. In some testcases,
as in PR 78407 this leads to noticeable improvements. */
if (speed_p && (optimize_edge_for_speed_p (taken_edge) || contains_hot_bb))
{
if (n_insns >= PARAM_VALUE (PARAM_MAX_FSM_THREAD_PATH_INSNS))
{