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re PR middle-end/82479 (missing popcount builtin detection)

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gcc/ChangeLog:

2018-06-16  Kugan Vivekanandarajah  <kuganv@linaro.org>

	PR middle-end/82479
	* ipa-fnsummary.c (will_be_nonconstant_expr_predicate): Handle CALL_EXPR.
	* tree-scalar-evolution.c (interpret_expr): Likewise.
	(expression_expensive_p): Likewise.
	* tree-ssa-loop-ivopts.c (contains_abnormal_ssa_name_p): Likewise.
	* tree-ssa-loop-niter.c (number_of_iterations_popcount): New.
	(number_of_iterations_exit_assumptions): Use number_of_iterations_popcount.
	(ssa_defined_by_minus_one_stmt_p): New.

gcc/testsuite/ChangeLog:

2018-06-16  Kugan Vivekanandarajah  <kuganv@linaro.org>

	PR middle-end/82479
	* gcc.dg/tree-ssa/popcount.c: New test.
	* gcc.dg/tree-ssa/popcount2.c: New test.

From-SVN: r261682
This commit is contained in:
Kugan Vivekanandarajah 2018-06-16 21:39:31 +00:00 • committed by Kugan Vivekanandarajah
parent e197e64ee8
commit 5126ae0c6e
8 changed files with 288 additions and 1 deletions
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11
gcc/ChangeLog
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@ -1,3 +1,14 @@
2018-06-16 Kugan Vivekanandarajah <kuganv@linaro.org>
PR middle-end/82479
* ipa-fnsummary.c (will_be_nonconstant_expr_predicate): Handle CALL_EXPR.
* tree-scalar-evolution.c (interpret_expr): Likewise.
(expression_expensive_p): Likewise.
* tree-ssa-loop-ivopts.c (contains_abnormal_ssa_name_p): Likewise.
* tree-ssa-loop-niter.c (number_of_iterations_popcount): New.
(number_of_iterations_exit_assumptions): Use number_of_iterations_popcount.
(ssa_defined_by_minus_one_stmt_p): New.
2018-06-16 Kugan Vivekanandarajah <kuganv@linaro.org>
PR middle-end/64946

2
gcc/ipa-fnsummary.c
View file

@ -1487,6 +1487,8 @@ will_be_nonconstant_expr_predicate (struct ipa_node_params *info,
nonconstant_names);
return p2.or_with (summary->conds, p1);
}
else if (TREE_CODE (expr) == CALL_EXPR)
return true;
else
{
debug_tree (expr);

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2018-06-16 Kugan Vivekanandarajah <kuganv@linaro.org>
PR middle-end/82479
* gcc.dg/tree-ssa/popcount.c: New test.
* gcc.dg/tree-ssa/popcount2.c: New test.
2018-06-16 Kugan Vivekanandarajah <kuganv@linaro.org>
PR middle-end/64946

41
gcc/testsuite/gcc.dg/tree-ssa/popcount.c Normal file
View file

@ -0,0 +1,41 @@
/* { dg-do compile } */
/* { dg-options "-O3 -fdump-tree-optimized -fno-tree-ch" } */
extern int foo (int);
int PopCount (long b) {
int c = 0;
b++;
while (b) {
b &= b - 1;
c++;
}
return c;
}
int PopCount2 (long b) {
int c = 0;
while (b) {
b &= b - 1;
c++;
}
foo (c);
return foo (c);
}
void PopCount3 (long b1) {
for (long i = 0; i < b1; ++i)
{
long b = i;
int c = 0;
while (b) {
b &= b - 1;
c++;
}
foo (c);
}
}
/* { dg-final { scan-tree-dump-times "__builtin_popcount" 3 "optimized" } } */

28
gcc/testsuite/gcc.dg/tree-ssa/popcount2.c Normal file
View file

@ -0,0 +1,28 @@
/* { dg-do run } */
/* { dg-options "-O2 -fno-tree-ch -fdump-tree-optimized" } */
int
__attribute__ ((noinline, noclone))
foo (long b)
{
int c = 0;
while (b) {
b &= b - 1;
c++;
}
return c;
}
int main()
{
if (foo (7) != 3)
__builtin_abort ();
if (foo (0) != 0)
__builtin_abort ();
if (foo (0xff) != 8)
__builtin_abort ();
return 0;
}
/* { dg-final { scan-tree-dump-times "__builtin_popcount" 1 "optimized" } } */

15
gcc/tree-scalar-evolution.c
View file

@ -281,6 +281,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-ssa-propagate.h"
#include "gimple-fold.h"
#include "tree-into-ssa.h"
#include "builtins.h"
static tree analyze_scalar_evolution_1 (struct loop *, tree);
static tree analyze_scalar_evolution_for_address_of (struct loop *loop,
@ -1984,6 +1985,7 @@ interpret_expr (struct loop *loop, gimple *at_stmt, tree expr)
return expr;
if (TREE_CODE (expr) == POLYNOMIAL_CHREC
|| TREE_CODE (expr) == CALL_EXPR
|| get_gimple_rhs_class (TREE_CODE (expr)) == GIMPLE_TERNARY_RHS)
return chrec_dont_know;
@ -3493,6 +3495,19 @@ expression_expensive_p (tree expr)
return true;
}
if (code == CALL_EXPR)
{
tree arg;
call_expr_arg_iterator iter;
if (!is_inexpensive_builtin (get_callee_fndecl (expr)))
return true;
FOR_EACH_CALL_EXPR_ARG (arg, iter, expr)
if (expression_expensive_p (arg))
return true;
return false;
}
switch (TREE_CODE_CLASS (code))
{
case tcc_binary:

10
gcc/tree-ssa-loop-ivopts.c
View file

@ -985,6 +985,16 @@ contains_abnormal_ssa_name_p (tree expr)
code = TREE_CODE (expr);
codeclass = TREE_CODE_CLASS (code);
if (code == CALL_EXPR)
{
tree arg;
call_expr_arg_iterator iter;
FOR_EACH_CALL_EXPR_ARG (arg, iter, expr)
if (contains_abnormal_ssa_name_p (arg))
return true;
return false;
}
if (code == SSA_NAME)
return SSA_NAME_OCCURS_IN_ABNORMAL_PHI (expr) != 0;

176
gcc/tree-ssa-loop-niter.c
View file

@ -63,6 +63,10 @@ struct bounds
mpz_t below, up;
};
static bool number_of_iterations_popcount (loop_p loop, edge exit,
enum tree_code code,
struct tree_niter_desc *niter);
/* Splits expression EXPR to a variable part VAR and constant OFFSET. */
@ -2357,7 +2361,7 @@ number_of_iterations_exit_assumptions (struct loop *loop, edge exit,
tree iv0_niters = NULL_TREE;
if (!simple_iv_with_niters (loop, loop_containing_stmt (stmt),
op0, &iv0, safe ? &iv0_niters : NULL, false))
return false;
return number_of_iterations_popcount (loop, exit, code, niter);
tree iv1_niters = NULL_TREE;
if (!simple_iv_with_niters (loop, loop_containing_stmt (stmt),
op1, &iv1, safe ? &iv1_niters : NULL, false))
@ -2430,6 +2434,176 @@ number_of_iterations_exit_assumptions (struct loop *loop, edge exit,
return (!integer_zerop (niter->assumptions));
}
/* Utility function to check if OP is defined by a stmt
that is a val - 1. */
static bool
ssa_defined_by_minus_one_stmt_p (tree op, tree val)
{
gimple *stmt;
return (TREE_CODE (op) == SSA_NAME
&& (stmt = SSA_NAME_DEF_STMT (op))
&& is_gimple_assign (stmt)
&& (gimple_assign_rhs_code (stmt) == PLUS_EXPR)
&& val == gimple_assign_rhs1 (stmt)
&& integer_minus_onep (gimple_assign_rhs2 (stmt)));
}
/* See if LOOP is a popcout implementation, determine NITER for the loop
We match:
<bb 2>
goto <bb 4>
<bb 3>
_1 = b_11 + -1
b_6 = _1 & b_11
<bb 4>
b_11 = PHI <b_5(D)(2), b_6(3)>
exit block
if (b_11 != 0)
goto <bb 3>
else
goto <bb 5>
OR we match copy-header version:
if (b_5 != 0)
goto <bb 3>
else
goto <bb 4>
<bb 3>
b_11 = PHI <b_5(2), b_6(3)>
_1 = b_11 + -1
b_6 = _1 & b_11
exit block
if (b_6 != 0)
goto <bb 3>
else
goto <bb 4>
If popcount pattern, update NITER accordingly.
i.e., set NITER to __builtin_popcount (b)
return true if we did, false otherwise.
*/
static bool
number_of_iterations_popcount (loop_p loop, edge exit,
enum tree_code code,
struct tree_niter_desc *niter)
{
bool adjust = true;
tree iter;
HOST_WIDE_INT max;
adjust = true;
tree fn = NULL_TREE;
/* Check loop terminating branch is like
if (b != 0). */
gimple *stmt = last_stmt (exit->src);
if (!stmt
|| gimple_code (stmt) != GIMPLE_COND
|| code != NE_EXPR
|| !integer_zerop (gimple_cond_rhs (stmt))
|| TREE_CODE (gimple_cond_lhs (stmt)) != SSA_NAME)
return false;
gimple *and_stmt = SSA_NAME_DEF_STMT (gimple_cond_lhs (stmt));
/* Depending on copy-header is performed, feeding PHI stmts might be in
the loop header or loop latch, handle this. */
if (gimple_code (and_stmt) == GIMPLE_PHI
&& gimple_bb (and_stmt) == loop->header
&& gimple_phi_num_args (and_stmt) == 2
&& (TREE_CODE (gimple_phi_arg_def (and_stmt,
loop_latch_edge (loop)->dest_idx))
== SSA_NAME))
{
/* SSA used in exit condition is defined by PHI stmt
b_11 = PHI <b_5(D)(2), b_6(3)>
from the PHI stmt, get the and_stmt
b_6 = _1 & b_11. */
tree t = gimple_phi_arg_def (and_stmt, loop_latch_edge (loop)->dest_idx);
and_stmt = SSA_NAME_DEF_STMT (t);
adjust = false;
}
/* Make sure it is indeed an and stmt (b_6 = _1 & b_11). */
if (!is_gimple_assign (and_stmt)
|| gimple_assign_rhs_code (and_stmt) != BIT_AND_EXPR)
return false;
tree b_11 = gimple_assign_rhs1 (and_stmt);
tree _1 = gimple_assign_rhs2 (and_stmt);
/* Check that _1 is defined by _b11 + -1 (_1 = b_11 + -1).
Also make sure that b_11 is the same in and_stmt and _1 defining stmt.
Also canonicalize if _1 and _b11 are revrsed. */
if (ssa_defined_by_minus_one_stmt_p (b_11, _1))
std::swap (b_11, _1);
else if (ssa_defined_by_minus_one_stmt_p (_1, b_11))
;
else
return false;
/* Check the recurrence:
... = PHI <b_5(2), b_6(3)>. */
gimple *phi = SSA_NAME_DEF_STMT (b_11);
if (gimple_code (phi) != GIMPLE_PHI
|| (gimple_assign_lhs (and_stmt)
!= gimple_phi_arg_def (phi, loop_latch_edge (loop)->dest_idx)))
return false;
/* We found a match. Get the corresponding popcount builtin. */
tree src = gimple_phi_arg_def (phi, loop_preheader_edge (loop)->dest_idx);
if (TYPE_PRECISION (TREE_TYPE (src)) == TYPE_PRECISION (integer_type_node))
fn = builtin_decl_implicit (BUILT_IN_POPCOUNT);
else if (TYPE_PRECISION (TREE_TYPE (src)) == TYPE_PRECISION
(long_integer_type_node))
fn = builtin_decl_implicit (BUILT_IN_POPCOUNTL);
else if (TYPE_PRECISION (TREE_TYPE (src)) == TYPE_PRECISION
(long_long_integer_type_node))
fn = builtin_decl_implicit (BUILT_IN_POPCOUNTLL);
/* ??? Support promoting char/short to int. */
if (!fn)
return false;
/* Update NITER params accordingly */
max = TYPE_PRECISION (TREE_TYPE (src));
if (adjust)
max = max - 1;
tree utype = unsigned_type_for (TREE_TYPE (src));
src = fold_convert (utype, src);
tree call = fold_convert (utype, build_call_expr (fn, 1, src));
if (adjust)
iter = fold_build2 (MINUS_EXPR, utype,
call,
build_int_cst (utype, 1));
else
iter = call;
niter->niter = iter;
niter->assumptions = boolean_true_node;
if (adjust)
niter->may_be_zero = fold_build2 (EQ_EXPR, boolean_type_node, src,
build_zero_cst
(TREE_TYPE (src)));
else
niter->may_be_zero = boolean_false_node;
niter->max = max;
niter->bound = NULL_TREE;
niter->cmp = ERROR_MARK;
return true;
}
/* Like number_of_iterations_exit_assumptions, but return TRUE only if
the niter information holds unconditionally. */