Extend is_cond_scalar_reduction to handle nop_expr after/before scalar reduction.[PR98365]

gcc/ChangeLog:

	PR tree-optimization/98365
	* tree-if-conv.c (strip_nop_cond_scalar_reduction): New function.
	(is_cond_scalar_reduction): Handle nop_expr in cond scalar reduction.
	(convert_scalar_cond_reduction): Ditto.
	(predicate_scalar_phi): Ditto.

gcc/testsuite/ChangeLog:

	PR tree-optimization/98365
	* gcc.target/i386/pr98365.c: New test.
This commit is contained in:
liuhongt 2021-01-06 16:33:27 +08:00
parent 715914d3f9
commit 28daadc980
2 changed files with 146 additions and 18 deletions

View File

@ -0,0 +1,22 @@
/* { dg-do compile } */
/* { dg-options "-O2 -mavx2 -ftree-vectorize -fdump-tree-vect-details" } */
/* { dg-final { scan-tree-dump-times "vectorized \[1-3] loops" 2 "vect" } } */
short foo1 (short* a, short* c, int n)
{
int i;
short cnt=0;
for (int i = 0;i != n; i++)
if (a[i] == c[i])
cnt++;
return cnt;
}
char foo2 (char* a, char* c, int n)
{
int i;
char cnt=0;
for (int i = 0;i != n; i++)
if (a[i] == c[i])
cnt++;
return cnt;
}

View File

@ -1579,6 +1579,31 @@ if_convertible_loop_p (class loop *loop)
return res;
}
/* Return reduc_1 if has_nop.
if (...)
tmp1 = (unsigned type) reduc_1;
tmp2 = tmp1 + rhs2;
reduc_3 = (signed type) tmp2. */
static tree
strip_nop_cond_scalar_reduction (bool has_nop, tree op)
{
if (!has_nop)
return op;
if (TREE_CODE (op) != SSA_NAME)
return NULL_TREE;
gassign *stmt = safe_dyn_cast <gassign *> (SSA_NAME_DEF_STMT (op));
if (!stmt
|| !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt))
|| !tree_nop_conversion_p (TREE_TYPE (op), TREE_TYPE
(gimple_assign_rhs1 (stmt))))
return NULL_TREE;
return gimple_assign_rhs1 (stmt);
}
/* Returns true if def-stmt for phi argument ARG is simple increment/decrement
which is in predicated basic block.
In fact, the following PHI pattern is searching:
@ -1595,9 +1620,10 @@ if_convertible_loop_p (class loop *loop)
static bool
is_cond_scalar_reduction (gimple *phi, gimple **reduc, tree arg_0, tree arg_1,
tree *op0, tree *op1, bool extended)
tree *op0, tree *op1, bool extended, bool* has_nop,
gimple **nop_reduc)
{
tree lhs, r_op1, r_op2;
tree lhs, r_op1, r_op2, r_nop1, r_nop2;
gimple *stmt;
gimple *header_phi = NULL;
enum tree_code reduction_op;
@ -1608,7 +1634,7 @@ is_cond_scalar_reduction (gimple *phi, gimple **reduc, tree arg_0, tree arg_1,
use_operand_p use_p;
edge e;
edge_iterator ei;
bool result = false;
bool result = *has_nop = false;
if (TREE_CODE (arg_0) != SSA_NAME || TREE_CODE (arg_1) != SSA_NAME)
return false;
@ -1656,18 +1682,77 @@ is_cond_scalar_reduction (gimple *phi, gimple **reduc, tree arg_0, tree arg_1,
return false;
reduction_op = gimple_assign_rhs_code (stmt);
/* Catch something like below
loop-header:
reduc_1 = PHI <..., reduc_2>
...
if (...)
tmp1 = (unsigned type) reduc_1;
tmp2 = tmp1 + rhs2;
reduc_3 = (signed type) tmp2;
reduc_2 = PHI <reduc_1, reduc_3>
and convert to
reduc_2 = PHI <0, reduc_3>
tmp1 = (unsigned type)reduce_1;
ifcvt = cond_expr ? rhs2 : 0
tmp2 = tmp1 +/- ifcvt;
reduce_1 = (signed type)tmp2; */
if (CONVERT_EXPR_CODE_P (reduction_op))
{
lhs = gimple_assign_rhs1 (stmt);
if (TREE_CODE (lhs) != SSA_NAME
|| !has_single_use (lhs))
return false;
*nop_reduc = stmt;
stmt = SSA_NAME_DEF_STMT (lhs);
if (gimple_bb (stmt) != gimple_bb (*nop_reduc)
|| !is_gimple_assign (stmt))
return false;
*has_nop = true;
reduction_op = gimple_assign_rhs_code (stmt);
}
if (reduction_op != PLUS_EXPR && reduction_op != MINUS_EXPR)
return false;
r_op1 = gimple_assign_rhs1 (stmt);
r_op2 = gimple_assign_rhs2 (stmt);
r_nop1 = strip_nop_cond_scalar_reduction (*has_nop, r_op1);
r_nop2 = strip_nop_cond_scalar_reduction (*has_nop, r_op2);
/* Make R_OP1 to hold reduction variable. */
if (r_op2 == PHI_RESULT (header_phi)
if (r_nop2 == PHI_RESULT (header_phi)
&& reduction_op == PLUS_EXPR)
std::swap (r_op1, r_op2);
else if (r_op1 != PHI_RESULT (header_phi))
{
std::swap (r_op1, r_op2);
std::swap (r_nop1, r_nop2);
}
else if (r_nop1 != PHI_RESULT (header_phi))
return false;
if (*has_nop)
{
/* Check that R_NOP1 is used in nop_stmt or in PHI only. */
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, r_nop1)
{
gimple *use_stmt = USE_STMT (use_p);
if (is_gimple_debug (use_stmt))
continue;
if (use_stmt == SSA_NAME_DEF_STMT (r_op1))
continue;
if (use_stmt != phi)
return false;
}
}
/* Check that R_OP1 is used in reduction stmt or in PHI only. */
FOR_EACH_IMM_USE_FAST (use_p, imm_iter, r_op1)
{
@ -1705,7 +1790,8 @@ is_cond_scalar_reduction (gimple *phi, gimple **reduc, tree arg_0, tree arg_1,
static tree
convert_scalar_cond_reduction (gimple *reduc, gimple_stmt_iterator *gsi,
tree cond, tree op0, tree op1, bool swap)
tree cond, tree op0, tree op1, bool swap,
bool has_nop, gimple* nop_reduc)
{
gimple_stmt_iterator stmt_it;
gimple *new_assign;
@ -1714,6 +1800,7 @@ convert_scalar_cond_reduction (gimple *reduc, gimple_stmt_iterator *gsi,
tree tmp = make_temp_ssa_name (TREE_TYPE (rhs1), NULL, "_ifc_");
tree c;
tree zero = build_zero_cst (TREE_TYPE (rhs1));
gimple_seq stmts = NULL;
if (dump_file && (dump_flags & TDF_DETAILS))
{
@ -1732,8 +1819,18 @@ convert_scalar_cond_reduction (gimple *reduc, gimple_stmt_iterator *gsi,
new_assign = gimple_build_assign (tmp, c);
gsi_insert_before (gsi, new_assign, GSI_SAME_STMT);
/* Build rhs for unconditional increment/decrement. */
rhs = fold_build2 (gimple_assign_rhs_code (reduc),
TREE_TYPE (rhs1), op0, tmp);
rhs = gimple_build (&stmts, gimple_assign_rhs_code (reduc),
TREE_TYPE (rhs1), op0, tmp);
if (has_nop)
{
rhs = gimple_convert (&stmts,
TREE_TYPE (gimple_assign_lhs (nop_reduc)), rhs);
stmt_it = gsi_for_stmt (nop_reduc);
gsi_remove (&stmt_it, true);
release_defs (nop_reduc);
}
gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
/* Delete original reduction stmt. */
stmt_it = gsi_for_stmt (reduc);
@ -1808,7 +1905,7 @@ ifcvt_follow_ssa_use_edges (tree val)
static void
predicate_scalar_phi (gphi *phi, gimple_stmt_iterator *gsi)
{
gimple *new_stmt = NULL, *reduc;
gimple *new_stmt = NULL, *reduc, *nop_reduc;
tree rhs, res, arg0, arg1, op0, op1, scev;
tree cond;
unsigned int index0;
@ -1816,6 +1913,7 @@ predicate_scalar_phi (gphi *phi, gimple_stmt_iterator *gsi)
edge e;
basic_block bb;
unsigned int i;
bool has_nop;
res = gimple_phi_result (phi);
if (virtual_operand_p (res))
@ -1876,10 +1974,15 @@ predicate_scalar_phi (gphi *phi, gimple_stmt_iterator *gsi)
arg1 = gimple_phi_arg_def (phi, 1);
}
if (is_cond_scalar_reduction (phi, &reduc, arg0, arg1,
&op0, &op1, false))
/* Convert reduction stmt into vectorizable form. */
rhs = convert_scalar_cond_reduction (reduc, gsi, cond, op0, op1,
true_bb != gimple_bb (reduc));
&op0, &op1, false, &has_nop,
&nop_reduc))
{
/* Convert reduction stmt into vectorizable form. */
rhs = convert_scalar_cond_reduction (reduc, gsi, cond, op0, op1,
true_bb != gimple_bb (reduc),
has_nop, nop_reduc);
redundant_ssa_names.safe_push (std::make_pair (res, rhs));
}
else
/* Build new RHS using selected condition and arguments. */
rhs = fold_build_cond_expr (TREE_TYPE (res), unshare_expr (cond),
@ -1961,14 +2064,17 @@ predicate_scalar_phi (gphi *phi, gimple_stmt_iterator *gsi)
is_gimple_condexpr, NULL_TREE,
true, GSI_SAME_STMT);
if (!(is_cond_scalar_reduction (phi, &reduc, arg0 , arg1,
&op0, &op1, true)))
&op0, &op1, true, &has_nop, &nop_reduc)))
rhs = fold_build_cond_expr (TREE_TYPE (res), unshare_expr (cond),
swap? arg1 : arg0,
swap? arg0 : arg1);
else
/* Convert reduction stmt into vectorizable form. */
rhs = convert_scalar_cond_reduction (reduc, gsi, cond, op0, op1,
swap);
{
/* Convert reduction stmt into vectorizable form. */
rhs = convert_scalar_cond_reduction (reduc, gsi, cond, op0, op1,
swap,has_nop, nop_reduc);
redundant_ssa_names.safe_push (std::make_pair (res, rhs));
}
new_stmt = gimple_build_assign (res, rhs);
gsi_insert_before (gsi, new_stmt, GSI_SAME_STMT);
update_stmt (new_stmt);