OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

re PR tree-optimization/79389 (30% performance regression in SciMark2 MonteCarlo)

Browse Source 
2017-02-24  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/79389
	* gimple-ssa-split-paths.c (is_feasible_trace): Verify more
	properly that a threading opportunity exists.  Detect conditional
	copy/constant propagation opportunities.

	* gcc.dg/tree-ssa/split-path-10.c: New testcase.

From-SVN: r245696
This commit is contained in:
Richard Biener 2017-02-24 08:04:31 +00:00 committed by Richard Biener
parent f83002c7ba
commit 7699e88f68
4 changed files with 108 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
gcc/ChangeLog
View File

@ -1,3 +1,10 @@
2017-02-24 Richard Biener <rguenther@suse.de>
PR tree-optimization/79389
* gimple-ssa-split-paths.c (is_feasible_trace): Verify more
properly that a threading opportunity exists. Detect conditional
copy/constant propagation opportunities.
2017-02-23 Eric Botcazou <ebotcazou@adacore.com>
* config/visium/visium.md (type): Add trap.

47
gcc/gimple-ssa-split-paths.c
View File

@ -232,12 +232,32 @@ is_feasible_trace (basic_block bb)
/* But for memory the PHI alone isn't good enough. */
&& ! virtual_operand_p (gimple_phi_result (stmt)))
{
bool found_unchanged_path = false;
for (unsigned i = 0; i < gimple_phi_num_args (phi); ++i)
if (gimple_phi_arg_def (phi, i) == gimple_phi_result (stmt))
{
found_unchanged_path = true;
break;
}
/* If we found an unchanged path this can only be a threading
opportunity if we have uses of the loop header PHI result
in a stmt dominating the merge block. Otherwise the
splitting may prevent if-conversion. */
if (found_unchanged_path)
{
use_operand_p use2_p;
imm_use_iterator iter2;
FOR_EACH_IMM_USE_FAST (use2_p, iter2, gimple_phi_result (stmt))
{
basic_block use_bb = gimple_bb (USE_STMT (use2_p));
if (use_bb != bb
&& dominated_by_p (CDI_DOMINATORS, bb, use_bb))
{
found_useful_phi = true;
break;
}
}
}
if (found_useful_phi)
break;
}
@ -245,7 +265,32 @@ is_feasible_trace (basic_block bb)
if (found_useful_phi)
break;
}
if (! found_useful_phi)
/* There is one exception namely a controlling condition we can propagate
an equivalence from to the joiner. */
bool found_cprop_opportunity = false;
basic_block dom = get_immediate_dominator (CDI_DOMINATORS, bb);
gcond *cond = as_a <gcond *> (last_stmt (dom));
if (gimple_cond_code (cond) == EQ_EXPR
|| gimple_cond_code (cond) == NE_EXPR)
for (unsigned i = 0; i < 2; ++i)
{
tree op = gimple_op (cond, i);
if (TREE_CODE (op) == SSA_NAME)
{
use_operand_p use_p;
imm_use_iterator iter;
FOR_EACH_IMM_USE_FAST (use_p, iter, op)
if (gimple_bb (USE_STMT (use_p)) == bb)
{
found_cprop_opportunity = true;
break;
}
}
if (found_cprop_opportunity)
break;
}
if (! found_useful_phi && ! found_cprop_opportunity)
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file,

5
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,8 @@
2017-02-24 Richard Biener <rguenther@suse.de>
PR tree-optimization/79389
* gcc.dg/tree-ssa/split-path-10.c: New testcase.
2017-02-23 Paolo Carlini <paolo.carlini@oracle.com>
PR c++/79361

49
gcc/testsuite/gcc.dg/tree-ssa/split-path-10.c Normal file
View File

@ -0,0 +1,49 @@
/* PR tree-optimization/79389 */
/* { dg-do compile } */
/* { dg-options "-O3 -fdump-tree-split-paths-details" } */
typedef struct
{
int m[17];
int seed;
int i;
int j;
int haveRange;
double left;
double right;
double width;
}
Random_struct, *Random;
Random new_Random_seed(int seed);
double Random_nextDouble(Random R);
void Random_delete(Random R);
static const int SEED = 113;
double MonteCarlo_integrate(int Num_samples)
{
Random R = new_Random_seed(SEED);
int under_curve = 0;
int count;
for (count=0; count<Num_samples; count++)
{
double x= Random_nextDouble(R);
double y= Random_nextDouble(R);
if ( x*x + y*y <= 1.0)
under_curve ++;
}
Random_delete(R);
return ((double) under_curve / Num_samples) * 4.0;
}
/* { dg-final { scan-tree-dump-times "Duplicating join block" 0 "split-paths" } } */