Hi Bin,
Thanks a lo for the review.
On 1 June 2018 at 03:45, Bin.Cheng <amker.ch...@gmail.com> wrote:
> On Thu, May 31, 2018 at 3:51 AM, Kugan Vivekanandarajah
> <kugan.vivekanandara...@linaro.org> wrote:
>> Hi Bin,
>>
>> Thanks for the review. Please find the revised patch based on the
>> review comments.
>>
>> Thanks,
>> Kugan
>>
>> On 17 May 2018 at 19:56, Bin.Cheng <amker.ch...@gmail.com> wrote:
>>> On Thu, May 17, 2018 at 2:39 AM, Kugan Vivekanandarajah
>>> <kugan.vivekanandara...@linaro.org> wrote:
>>>> Hi Richard,
>>>>
>>>> On 6 March 2018 at 02:24, Richard Biener <richard.guent...@gmail.com>
>>>> wrote:
>>>>> On Thu, Feb 8, 2018 at 1:41 AM, Kugan Vivekanandarajah
>>>>> <kugan.vivekanandara...@linaro.org> wrote:
>>>>>> Hi Richard,
>>>>>>
>
> Hi,
> Thanks very much for working.
>
>> +/* Utility function to check if OP is defined by a stmt
>> + that is a val - 1. If that is the case, set it to STMT. */
>> +
>> +static bool
>> +ssa_defined_by_and_minus_one_stmt_p (tree op, tree val, gimple **stmt)
> This is checking if op is defined as val - 1, so name it as
> ssa_defined_by_minus_one_stmt_p?
>
>> +{
>> + if (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)))
>> + return true;
>> + else
>> + return false;
> You can simply return the boolean condition.
Done.
>
>> +}
>> +
>> +/* See if LOOP is a popcout implementation of the form
> ...
>> + rhs1 = gimple_assign_rhs1 (and_stmt);
>> + rhs2 = gimple_assign_rhs2 (and_stmt);
>> +
>> + if (ssa_defined_by_and_minus_one_stmt_p (rhs1, rhs2, &and_minus_one))
>> + rhs1 = rhs2;
>> + else if (ssa_defined_by_and_minus_one_stmt_p (rhs2, rhs1, &and_minus_one))
>> + ;
>> + else
>> + return false;
>> +
>> + /* Check the recurrence. */
>> + phi = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (and_minus_one));
> So gimple_assign_rhs1 (and_minus_one) == rhs1 is always true? Please
> use rhs1 directly.
Done.
>> + gimple *src_phi = SSA_NAME_DEF_STMT (rhs2);
> I think this is checking wrong thing and is redundant. Either rhs2
> equals to rhs1 or is defined as (rhs1 - 1). For (rhs2 == rhs1) case,
> the check duplicates checking on phi; for the latter, it's never a PHI
> stmt and shouldn't be checked.
>
>> + if (gimple_code (phi) != GIMPLE_PHI
>> + || gimple_code (src_phi) != GIMPLE_PHI)
>> + return false;
>> +
>> + dest = gimple_assign_lhs (count_stmt);
>> + tree fn = builtin_decl_implicit (BUILT_IN_POPCOUNT);
>> + tree src = gimple_phi_arg_def (src_phi, loop_preheader_edge
>> (loop)->dest_idx);
>> + if (adjust)
>> + iter = fold_build2 (MINUS_EXPR, TREE_TYPE (dest),
>> + build_call_expr (fn, 1, src),
>> + build_int_cst (TREE_TYPE (dest), 1));
>> + else
>> + iter = build_call_expr (fn, 1, src);
> Note tree-ssa-loop-niters.c always use unsigned_type_for (IV-type) as
> niters type. Though unsigned type is unnecessary in this case, but
> better to follow existing behavior?
Done.
>
>> + max = int_cst_value (TYPE_MAX_VALUE (TREE_TYPE (dest)));
> As richi suggested, max should be the number of bits in type of IV.
>
>> +
>> + niter->assumptions = boolean_false_node;
> Redundant.
Not sure I understand. If I remove this, I am getting ICE
(segmentation fault). What is the expectation here?
>> + niter->control.base = NULL_TREE;
>> + niter->control.step = NULL_TREE;
>> + niter->control.no_overflow = false;
>> + niter->niter = iter;
>> + niter->assumptions = boolean_true_node;
>> + niter->may_be_zero = boolean_false_node;
>> + niter->max = max;
>> + niter->bound = NULL_TREE;
>> + niter->cmp = ERROR_MARK;
>> + return true;
>> +}
>> +
>> +
> Appology if these are nitpickings.
Thanks for the review. I am happy to make the changes needed to get it
to how it should be :)
Thanks,
Kugan
>
> Thanks,
> bin
From f45179c777d846731d2d899a142c45a36ab35fd1 Mon Sep 17 00:00:00 2001
From: Kugan Vivekanandarajah <kugan.vivekanandara...@linaro.org>
Date: Thu, 10 May 2018 21:41:53 +1000
Subject: [PATCH] popcount
Change-Id: I10c1f990e5b9c9900cf7c93678df924f0463b72e
---
gcc/ipa-fnsummary.c | 4 +
gcc/testsuite/gcc.dg/tree-ssa/popcount.c | 41 ++++++++
gcc/testsuite/gcc.dg/tree-ssa/popcount2.c | 29 ++++++
gcc/testsuite/gcc.dg/tree-ssa/popcount3.c | 28 ++++++
gcc/tree-scalar-evolution.c | 7 ++
gcc/tree-ssa-loop-ivopts.c | 10 ++
gcc/tree-ssa-loop-niter.c | 152 +++++++++++++++++++++++++++++-
7 files changed, 270 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount2.c
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/popcount3.c
diff --git a/gcc/ipa-fnsummary.c b/gcc/ipa-fnsummary.c
index bdf9ba1..4dc156a 100644
--- a/gcc/ipa-fnsummary.c
+++ b/gcc/ipa-fnsummary.c
@@ -1485,6 +1485,10 @@ 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 false;
+ }
else
{
debug_tree (expr);
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount.c b/gcc/testsuite/gcc.dg/tree-ssa/popcount.c
new file mode 100644
index 0000000..86a66cb
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount.c
@@ -0,0 +1,41 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -fdump-tree-optimized" } */
+
+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" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount2.c b/gcc/testsuite/gcc.dg/tree-ssa/popcount2.c
new file mode 100644
index 0000000..52afc2d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount2.c
@@ -0,0 +1,29 @@
+/* { dg-do execute } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+int
+__attribute__ ((noinline, noclone))
+foo (int i, long b)
+{
+ int c = i;
+
+ while (b) {
+ b &= b - 1;
+ c++;
+ }
+ return c;
+}
+
+int main()
+{
+
+ if (foo (1, 7) != 4)
+ __builtin_abort ();
+ if (foo (0, 0) != 0)
+ __builtin_abort ();
+ if (foo (8, 0xff) != 16)
+ __builtin_abort ();
+ return 0;
+}
+
+/* { dg-final { scan-tree-dump-times "__builtin_popcount" 1 "optimized" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/popcount3.c b/gcc/testsuite/gcc.dg/tree-ssa/popcount3.c
new file mode 100644
index 0000000..0c69d97
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/popcount3.c
@@ -0,0 +1,28 @@
+/* { dg-do execute } */
+/* { dg-options "-O2 -fno-tree-ch -fdump-tree-optimized" } */
+
+int
+__attribute__ ((noinline, noclone))
+foo (long b)
+{
+ int c = i;
+
+ 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" } } */
diff --git a/gcc/tree-scalar-evolution.c b/gcc/tree-scalar-evolution.c
index fefc9de..967b154 100644
--- a/gcc/tree-scalar-evolution.c
+++ b/gcc/tree-scalar-evolution.c
@@ -1984,6 +1984,7 @@ 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;
@@ -3472,6 +3473,7 @@ bool
expression_expensive_p (tree expr)
{
enum tree_code code;
+ tree fndecl;
if (is_gimple_val (expr))
return false;
@@ -3492,6 +3494,11 @@ expression_expensive_p (tree expr)
if (!integer_pow2p (TREE_OPERAND (expr, 1)))
return true;
}
+ if (code == CALL_EXPR
+ && (fndecl = get_callee_fndecl (expr))
+ && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
+ && (BUILT_IN_POPCOUNT == DECL_FUNCTION_CODE (fndecl)))
+ return false;
switch (TREE_CODE_CLASS (code))
{
diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c
index b313571..519649a 100644
--- a/gcc/tree-ssa-loop-ivopts.c
+++ b/gcc/tree-ssa-loop-ivopts.c
@@ -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;
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index 7a54c5f..fde9245 100644
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -2430,6 +2430,152 @@ 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. If that is the case, set it to STMT. */
+
+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 of the form
+
+ int c = 0;
+ while (b) {
+ b = b & (b - 1);
+ c++;
+ }
+
+ 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, struct tree_niter_desc *niter)
+{
+ tree rhs1, rhs2;
+ tree dest;
+ gimple *and_minus_one;
+ gimple *phi;
+ int count = 0;
+ gimple *count_stmt = NULL;
+ bool adjust = true;
+ edge exit;
+ tree iter;
+ HOST_WIDE_INT max;
+
+ if (!(exit = single_exit (loop)))
+ return false;
+
+ /* Check loop terminating branch is like
+ if (b != 0). */
+ gimple *stmt = last_stmt (loop->header);
+ if (!stmt
+ || gimple_code (stmt) != GIMPLE_COND
+ || gimple_cond_code (stmt) != NE_EXPR
+ || !zerop (gimple_cond_rhs (stmt))
+ || TREE_CODE (gimple_cond_lhs (stmt)) != SSA_NAME)
+ return false;
+
+ /* Check the loop closed SSA definition for just the variable c defined in
+ loop. */
+ basic_block bb = exit->dest;
+ for (gphi_iterator gpi = gsi_start_phis (bb);
+ !gsi_end_p (gpi); gsi_next (&gpi))
+ {
+ phi = gpi.phi ();
+ count++;
+ }
+
+ if (count != 1)
+ return false;
+
+ rhs1 = gimple_phi_arg_def (phi, exit->dest_idx);
+ if (TREE_CODE (rhs1) != SSA_NAME)
+ return false;
+ count_stmt = SSA_NAME_DEF_STMT (rhs1);
+ 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 exit, handle this. */
+ if (gimple_code (count_stmt) == GIMPLE_PHI)
+ {
+ tree t;
+ if (gimple_code (and_stmt) != GIMPLE_PHI
+ || gimple_bb (and_stmt) != exit->src
+ || gimple_bb (count_stmt) != exit->src)
+ return false;
+ t = gimple_phi_arg_def (count_stmt, loop_latch_edge (loop)->dest_idx);
+ if (TREE_CODE (t) != SSA_NAME)
+ return false;
+ count_stmt = SSA_NAME_DEF_STMT (t);
+ t = gimple_phi_arg_def (and_stmt, loop_latch_edge (loop)->dest_idx);
+ if (TREE_CODE (t) != SSA_NAME)
+ return false;
+ and_stmt = SSA_NAME_DEF_STMT (t);
+ adjust = false;
+ }
+
+ /* Make sure we have a count by one. */
+ if (!is_gimple_assign (count_stmt)
+ || (gimple_assign_rhs_code (count_stmt) != PLUS_EXPR)
+ || !integer_onep (gimple_assign_rhs2 (count_stmt)))
+ return false;
+
+ /* Check "b = b & (b - 1)" is calculated. */
+ if (!is_gimple_assign (and_stmt)
+ || gimple_assign_rhs_code (and_stmt) != BIT_AND_EXPR)
+ return false;
+
+ rhs1 = gimple_assign_rhs1 (and_stmt);
+ rhs2 = gimple_assign_rhs2 (and_stmt);
+
+ if (ssa_defined_by_minus_one_stmt_p (rhs1, rhs2, &and_minus_one))
+ std::swap (rhs1, rhs2);
+ else if (ssa_defined_by_minus_one_stmt_p (rhs2, rhs1, &and_minus_one))
+ ;
+ else
+ return false;
+
+ /* Check the recurrence. */
+ phi = SSA_NAME_DEF_STMT (rhs1);
+ if (gimple_code (phi) != GIMPLE_PHI)
+ return false;
+
+ dest = gimple_assign_lhs (count_stmt);
+ tree utype = unsigned_type_for (TREE_TYPE (dest));
+ tree fn = builtin_decl_implicit (BUILT_IN_POPCOUNT);
+ tree src = gimple_phi_arg_def (phi, loop_preheader_edge (loop)->dest_idx);
+ if (adjust)
+ iter = fold_build2 (MINUS_EXPR, utype,
+ build_call_expr (fn, 1, src),
+ build_int_cst (utype, 1));
+ else
+ iter = fold_convert (utype, build_call_expr (fn, 1, src));
+ max = int_cst_value (TYPE_MAX_VALUE (TREE_TYPE (dest)));
+
+ niter->assumptions = boolean_false_node;
+ niter->control.base = NULL_TREE;
+ niter->control.step = NULL_TREE;
+ niter->control.no_overflow = false;
+ niter->niter = iter;
+ niter->assumptions = boolean_true_node;
+ 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. */
@@ -2441,7 +2587,11 @@ number_of_iterations_exit (struct loop *loop, edge exit,
gcond *stmt;
if (!number_of_iterations_exit_assumptions (loop, exit, niter,
&stmt, every_iteration))
- return false;
+ {
+ if (number_of_iterations_popcount (loop, niter))
+ return true;
+ return false;
+ }
if (integer_nonzerop (niter->assumptions))
return true;
--
2.7.4
