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Handle SLP of call pattern statements

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We couldn't vectorise:

  for (int j = 0; j < n; ++j)
    {
      for (int i = 0; i < 16; ++i)
	a[i] = (b[i] + c[i]) >> 1;
      a += step;
      b += step;
      c += step;
    }

at -O3 because cunrolli unrolled the inner loop and SLP couldn't handle
AVG_FLOOR patterns (see also PR86504).  The problem was some overly
strict checking of pattern statements compared to normal statements
in vect_get_and_check_slp_defs:

          switch (gimple_code (def_stmt))
            {
            case GIMPLE_PHI:
            case GIMPLE_ASSIGN:
	      break;

	    default:
	      if (dump_enabled_p ())
		dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
				 "unsupported defining stmt:\n");
	      return -1;
            }

The easy fix would have been to add GIMPLE_CALL to the switch,
but I don't think the switch is doing anything useful.  We only create
pattern statements that the rest of the vectoriser can handle, and the
other checks in this function and elsewhere check whether SLP is possible.

I'm also not sure why:

          if (!first && !oprnd_info->first_pattern
	      /* Allow different pattern state for the defs of the
		 first stmt in reduction chains.  */
	      && (oprnd_info->first_dt != vect_reduction_def

is necessary.  All that should matter is that the statements in the
node are "similar enough".  It turned out to be quite hard to find a
convincing example that used a mixture of pattern and non-pattern
statements, so bb-slp-pow-1.c is the best I could come up with.
But it does show that the combination of "xi * xi" statements and
"pow (xj, 2) -> xj * xj" patterns are handled correctly.

The patch therefore just removes the whole if block.

The loop also needed commutative swapping to be extended to at least
AVG_FLOOR.

This gives +3.9% on 525.x264_r at -O3.

2018-08-03  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* internal-fn.h (first_commutative_argument): Declare.
	* internal-fn.c (first_commutative_argument): New function.
	* tree-vect-slp.c (vect_get_and_check_slp_defs): Remove extra
	restrictions for pattern statements.  Use first_commutative_argument
	to look for commutative operands in calls to internal functions.

gcc/testsuite/
	* gcc.dg/vect/bb-slp-over-widen-1.c: Expect AVG_FLOOR to be used
	on vect_avg_qi targets.
	* gcc.dg/vect/bb-slp-over-widen-2.c: Likewise.
	* gcc.dg/vect/bb-slp-pow-1.c: New test.
	* gcc.dg/vect/vect-avg-15.c: Likewise.

From-SVN: r263290
This commit is contained in:
Richard Sandiford 2018-08-03 12:56:55 +00:00 committed by Richard Sandiford
parent d7487e2ae8
commit 0246112a9d
9 changed files with 152 additions and 65 deletions
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8
gcc/ChangeLog
View File

@ -1,3 +1,11 @@
2018-08-03 Richard Sandiford <richard.sandiford@arm.com>
* internal-fn.h (first_commutative_argument): Declare.
* internal-fn.c (first_commutative_argument): New function.
* tree-vect-slp.c (vect_get_and_check_slp_defs): Remove extra
restrictions for pattern statements. Use first_commutative_argument
to look for commutative operands in calls to internal functions.
2018-08-03 Aldy Hernandez <aldyh@redhat.com>
* Makefile.in (wide-int-range.o): New.

36
gcc/internal-fn.c
View File

@ -3183,6 +3183,42 @@ direct_internal_fn_supported_p (internal_fn fn, tree type,
return direct_internal_fn_supported_p (fn, tree_pair (type, type), opt_type);
}
/* If FN is commutative in two consecutive arguments, return the
index of the first, otherwise return -1. */
int
first_commutative_argument (internal_fn fn)
{
switch (fn)
{
case IFN_FMA:
case IFN_FMS:
case IFN_FNMA:
case IFN_FNMS:
case IFN_AVG_FLOOR:
case IFN_AVG_CEIL:
case IFN_FMIN:
case IFN_FMAX:
return 0;
case IFN_COND_ADD:
case IFN_COND_MUL:
case IFN_COND_MIN:
case IFN_COND_MAX:
case IFN_COND_AND:
case IFN_COND_IOR:
case IFN_COND_XOR:
case IFN_COND_FMA:
case IFN_COND_FMS:
case IFN_COND_FNMA:
case IFN_COND_FNMS:
return 1;
default:
return -1;
}
}
/* Return true if IFN_SET_EDOM is supported. */
bool

2
gcc/internal-fn.h
View File

@ -201,6 +201,8 @@ direct_internal_fn_supported_p (internal_fn fn, tree type0, tree type1,
opt_type);
}
extern int first_commutative_argument (internal_fn);
extern bool set_edom_supported_p (void);
extern internal_fn get_conditional_internal_fn (tree_code);

8
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,11 @@
2018-08-03 Richard Sandiford <richard.sandiford@arm.com>
* gcc.dg/vect/bb-slp-over-widen-1.c: Expect AVG_FLOOR to be used
on vect_avg_qi targets.
* gcc.dg/vect/bb-slp-over-widen-2.c: Likewise.
* gcc.dg/vect/bb-slp-pow-1.c: New test.
* gcc.dg/vect/vect-avg-15.c: Likewise.
2018-08-03 Martin Liska <mliska@suse.cz>
* gcc.dg/predict-1.c: Adjust scanned pattern to cover 2 digits.

1
gcc/testsuite/gcc.dg/vect/bb-slp-over-widen-1.c
View File

@ -63,4 +63,5 @@ main (void)
/* { dg-final { scan-tree-dump "demoting int to signed short" "slp2" { target { ! vect_widen_shift } } } } */
/* { dg-final { scan-tree-dump "demoting int to unsigned short" "slp2" { target { ! vect_widen_shift } } } } */
/* { dg-final { scan-tree-dump {\.AVG_FLOOR} "slp2" { target vect_avg_qi } } } */
/* { dg-final { scan-tree-dump-times "basic block vectorized" 2 "slp2" } } */

1
gcc/testsuite/gcc.dg/vect/bb-slp-over-widen-2.c
View File

@ -62,4 +62,5 @@ main (void)
/* { dg-final { scan-tree-dump "demoting int to signed short" "slp2" { target { ! vect_widen_shift } } } } */
/* { dg-final { scan-tree-dump "demoting int to unsigned short" "slp2" { target { ! vect_widen_shift } } } } */
/* { dg-final { scan-tree-dump {\.AVG_FLOOR} "slp2" { target vect_avg_qi } } } */
/* { dg-final { scan-tree-dump-times "basic block vectorized" 2 "slp2" } } */

28
gcc/testsuite/gcc.dg/vect/bb-slp-pow-1.c Normal file
View File

@ -0,0 +1,28 @@
/* { dg-additional-options "-fno-math-errno -fdisable-tree-sincos" } */
/* { dg-require-effective-target vect_float } */
void __attribute__ ((noipa))
f (float *a)
{
a[0] = a[0] * a[0];
a[1] = __builtin_powf (a[1], 2);
a[2] = a[2] * a[2];
a[3] = __builtin_powf (a[3], 2);
}
float a[4] = { 1, 2, 3, 4 };
int
main (void)
{
f (a);
for (int i = 0; i < 4; ++i)
{
if (a[i] != (i + 1) * (i + 1))
__builtin_abort ();
asm volatile ("" ::: "memory");
}
return 0;
}
/* { dg-final { scan-tree-dump-times "basic block vectorized" 1 "slp2" } } */

52
gcc/testsuite/gcc.dg/vect/vect-avg-15.c Normal file
View File

@ -0,0 +1,52 @@
/* { dg-additional-options "-O3" } */
/* { dg-require-effective-target vect_int } */
#include "tree-vect.h"
#define N 80
void __attribute__ ((noipa))
f (signed char *restrict a, signed char *restrict b,
signed char *restrict c, int n, int step)
{
for (int j = 0; j < n; ++j)
{
for (int i = 0; i < 16; ++i)
a[i] = (b[i] + c[i]) >> 1;
a += step;
b += step;
c += step;
}
}
#define BASE1 -126
#define BASE2 -42
signed char a[N], b[N], c[N];
int
main (void)
{
check_vect ();
for (int i = 0; i < N; ++i)
{
a[i] = i;
b[i] = BASE1 + i * 3;
c[i] = BASE2 + i * 2;
asm volatile ("" ::: "memory");
}
f (a, b, c, N / 20, 20);
for (int i = 0; i < N; ++i)
{
int d = (BASE1 + BASE2 + i * 5) >> 1;
if (a[i] != (i % 20 < 16 ? d : i))
__builtin_abort ();
}
return 0;
}
/* { dg-final { scan-tree-dump "vect_recog_average_pattern: detected" "vect" } } */
/* { dg-final { scan-tree-dump {\.AVG_FLOOR} "vect" { target vect_avg_qi } } } */
/* { dg-final { scan-tree-dump "Loop contains only SLP stmts" "vect" { target vect_avg_qi } } } */
/* { dg-final { scan-tree-dump-times "vectorized 1 loop" 1 "vect" { target vect_avg_qi } } } */

81
gcc/tree-vect-slp.c
View File

@ -309,7 +309,7 @@ vect_get_and_check_slp_defs (vec_info *vinfo, unsigned char *swap,
bool pattern = false;
slp_oprnd_info oprnd_info;
int first_op_idx = 1;
bool commutative = false;
unsigned int commutative_op = -1U;
bool first_op_cond = false;
bool first = stmt_num == 0;
bool second = stmt_num == 1;
@ -318,6 +318,11 @@ vect_get_and_check_slp_defs (vec_info *vinfo, unsigned char *swap,
{
number_of_oprnds = gimple_call_num_args (stmt);
first_op_idx = 3;
if (gimple_call_internal_p (stmt))
{
internal_fn ifn = gimple_call_internal_fn (stmt);
commutative_op = first_commutative_argument (ifn);
}
}
else if (gassign *stmt = dyn_cast <gassign *> (stmt_info->stmt))
{
@ -332,7 +337,7 @@ vect_get_and_check_slp_defs (vec_info *vinfo, unsigned char *swap,
number_of_oprnds++;
}
else
commutative = commutative_tree_code (code);
commutative_op = commutative_tree_code (code) ? 0U : -1U;
}
else
return -1;
@ -373,62 +378,6 @@ again:
return -1;
}
/* Check if DEF_STMT_INFO is a part of a pattern in LOOP and get
the def stmt from the pattern. Check that all the stmts of the
node are in the pattern. */
if (def_stmt_info && is_pattern_stmt_p (def_stmt_info))
{
pattern = true;
if (!first && !oprnd_info->first_pattern
/* Allow different pattern state for the defs of the
first stmt in reduction chains. */
&& (oprnd_info->first_dt != vect_reduction_def
|| (!second && !oprnd_info->second_pattern)))
{
if (i == 0
&& !swapped
&& commutative)
{
swapped = true;
goto again;
}
if (dump_enabled_p ())
{
dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
"Build SLP failed: some of the stmts"
" are in a pattern, and others are not ");
dump_generic_expr (MSG_MISSED_OPTIMIZATION, TDF_SLIM, oprnd);
dump_printf (MSG_MISSED_OPTIMIZATION, "\n");
}
return 1;
}
dt = STMT_VINFO_DEF_TYPE (def_stmt_info);
if (dt == vect_unknown_def_type)
{
if (dump_enabled_p ())
dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
"Unsupported pattern.\n");
return -1;
}
switch (gimple_code (def_stmt_info->stmt))
{
case GIMPLE_PHI:
case GIMPLE_ASSIGN:
break;
default:
if (dump_enabled_p ())
dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location,
"unsupported defining stmt:\n");
return -1;
}
}
if (second)
oprnd_info->second_pattern = pattern;
@ -456,9 +405,7 @@ again:
|| !types_compatible_p (oprnd_info->first_op_type, type))
{
/* Try swapping operands if we got a mismatch. */
if (i == 0
&& !swapped
&& commutative)
if (i == commutative_op && !swapped)
{
swapped = true;
goto again;
@ -534,9 +481,9 @@ again:
return -1;
}
gassign *stmt = as_a <gassign *> (stmt_info->stmt);
if (first_op_cond)
{
gassign *stmt = as_a <gassign *> (stmt_info->stmt);
tree cond = gimple_assign_rhs1 (stmt);
enum tree_code code = TREE_CODE (cond);
@ -559,13 +506,17 @@ again:
}
}
else
swap_ssa_operands (stmt, gimple_assign_rhs1_ptr (stmt),
gimple_assign_rhs2_ptr (stmt));
{
unsigned int op = commutative_op + first_op_idx;
swap_ssa_operands (stmt_info->stmt,
gimple_op_ptr (stmt_info->stmt, op),
gimple_op_ptr (stmt_info->stmt, op + 1));
}
if (dump_enabled_p ())
{
dump_printf_loc (MSG_NOTE, vect_location,
"swapped operands to match def types in ");
dump_gimple_stmt (MSG_NOTE, TDF_SLIM, stmt, 0);
dump_gimple_stmt (MSG_NOTE, TDF_SLIM, stmt_info->stmt, 0);
}
}