diff mbox

[PR81408] Turn TREE level unsafe loop optimizations warning to missed optimization message

Message ID CAHFci28zd-FF6drH4k1UC9ab478zWOode1oju+_PGAvMwazMnw@mail.gmail.com
State New
Headers show

Commit Message

Bin.Cheng July 18, 2017, 9:13 a.m. UTC 
On Tue, Jul 18, 2017 at 9:31 AM, Richard Biener
<richard.guenther@gmail.com> wrote:
> On Tue, Jul 18, 2017 at 10:00 AM, Bin Cheng <Bin.Cheng@arm.com> wrote:
>> Hi,
>> I removed unsafe loop optimization on TREE level last year, so GCC doesn't do unsafe
>> loop optimizations on TREE now.  All "unsafe loop optimizations" warnings reported by
>> TREE optimizers are simply missed optimizations.  This patch turns such warning into
>> missed optimization messages.  I didn't change when this will be dumped, for now it is
>> when called from ivopts.
>> Bootstrap and test on x86_64 and AArch64.  Is it OK?
>
> Ok but can you change the testcase to not scan the ivopts dump but use
> -fopt-info-loop-missed?
> You should be able to match the output with dg-message.
Thanks for reviewing.  New patch with test case updated accordingly.  Is it OK?

Thanks,
bin
>
> Thanks,
> Richard.
>
>> Thanks,
>> bin
>> 2017-07-13  Bin Cheng  <bin.cheng@arm.com>
>>
>>         PR target/81408
>>         * tree-ssa-loop-niter.c (number_of_iterations_exit): Dump missed
>>         optimization for loop niter analysis.
>>
>> gcc/testsuite/ChangeLog
>> 2017-07-13  Bin Cheng  <bin.cheng@arm.com>
>>
>>         PR target/81408
>>         * g++.dg/tree-ssa/pr81408.C: New.
>>         * gcc.dg/tree-ssa/pr19210-1.c: Check dump message rather than warning.

Comments

Richard Biener July 18, 2017, 11:22 a.m. UTC | #1 
On Tue, Jul 18, 2017 at 11:13 AM, Bin.Cheng <amker.cheng@gmail.com> wrote:
> On Tue, Jul 18, 2017 at 9:31 AM, Richard Biener
> <richard.guenther@gmail.com> wrote:
>> On Tue, Jul 18, 2017 at 10:00 AM, Bin Cheng <Bin.Cheng@arm.com> wrote:
>>> Hi,
>>> I removed unsafe loop optimization on TREE level last year, so GCC doesn't do unsafe
>>> loop optimizations on TREE now.  All "unsafe loop optimizations" warnings reported by
>>> TREE optimizers are simply missed optimizations.  This patch turns such warning into
>>> missed optimization messages.  I didn't change when this will be dumped, for now it is
>>> when called from ivopts.
>>> Bootstrap and test on x86_64 and AArch64.  Is it OK?
>>
>> Ok but can you change the testcase to not scan the ivopts dump but use
>> -fopt-info-loop-missed?
>> You should be able to match the output with dg-message.
> Thanks for reviewing.  New patch with test case updated accordingly.  Is it OK?

Ok.

Richard.

> Thanks,
> bin
>>
>> Thanks,
>> Richard.
>>
>>> Thanks,
>>> bin
>>> 2017-07-13  Bin Cheng  <bin.cheng@arm.com>
>>>
>>>         PR target/81408
>>>         * tree-ssa-loop-niter.c (number_of_iterations_exit): Dump missed
>>>         optimization for loop niter analysis.
>>>
>>> gcc/testsuite/ChangeLog
>>> 2017-07-13  Bin Cheng  <bin.cheng@arm.com>
>>>
>>>         PR target/81408
>>>         * g++.dg/tree-ssa/pr81408.C: New.
>>>         * gcc.dg/tree-ssa/pr19210-1.c: Check dump message rather than warning.
diff mbox

Patch

diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr81408.C b/gcc/testsuite/g++.dg/tree-ssa/pr81408.C
new file mode 100644
index 0000000..f94544b
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr81408.C
@@ -0,0 +1,92 @@ 
+/* { dg-do compile } */
+/* { dg-options "-O2 -std=gnu++11 -fopt-info-loop-missed -Wunsafe-loop-optimizations" } */
+
+namespace a {
+void b () __attribute__ ((__noreturn__));
+template <typename> struct d;
+template <typename e> struct d<e *>
+{
+  typedef e f;
+};
+struct g
+{
+  template <typename h> using i = h *;
+};
+}
+using a::d;
+template <typename j, typename> class k
+{
+  j l;
+
+public:
+  typename d<j>::f operator* () {}
+  void operator++ () { ++l; }
+  j
+  aa ()
+  {
+    return l;
+  }
+};
+template <typename m, typename n, typename ab>
+bool
+operator!= (k<m, ab> o, k<n, ab> p2)
+{
+  return o.aa () != p2.aa ();
+}
+struct p;
+namespace a {
+struct F
+{
+  struct q
+  {
+    using ai = g::i<p>;
+  };
+  using r = q::ai;
+};
+class H
+{
+public:
+  k<F::r, int> begin ();
+  k<F::r, int> end ();
+};
+int s;
+class I
+{
+public:
+  void
+  aq (char)
+  {
+    if (s)
+      b ();
+  }
+};
+class u : public I
+{
+public:
+  void
+  operator<< (u o (u))
+  {
+    o (*this);
+  }
+  u operator<< (void *);
+};
+template <typename at, typename au>
+at
+av (au o)
+{
+  o.aq ('\n');
+}
+u ax;
+}
+struct p
+{
+  char *ay;
+};
+a::H t;
+void
+ShowHelpListCommands ()
+{
+  for (auto c : t) /* { dg-message "note: missed loop optimization: niters analysis .*" } */
+    a::ax << c.ay << a::av;
+}
+
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c b/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c
index 3c8ee06..0fa5600 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c
@@ -1,15 +1,15 @@ 
 /* { dg-do compile } */
-/* { dg-options "-O2 -Wunsafe-loop-optimizations" } */
+/* { dg-options "-O2 -fopt-info-loop-missed -Wunsafe-loop-optimizations" } */
 extern void g(void);
 
 void
 f (unsigned n)
 {
   unsigned k;
-  for(k = 0;k <= n;k++) /* { dg-warning "missed loop optimization.*overflow" } */
+  for(k = 0;k <= n;k++) /* { dg-message "note: missed loop optimization: niters analysis .*" } */
     g();
 
-  for(k = 0;k <= n;k += 4) /* { dg-warning "missed loop optimization.*overflow" } */
+  for(k = 0;k <= n;k += 4) /* { dg-message "note: missed loop optimization: niters analysis .*" } */
     g();
 
   /* We used to get warning for this loop.  However, since then # of iterations
@@ -21,9 +21,9 @@  f (unsigned n)
     g();
 
   /* So we need the following loop, instead.  */
-  for(k = 4;k <= n;k += 5) /* { dg-warning "missed loop optimization.*overflow" } */
+  for(k = 4;k <= n;k += 5) /* { dg-message "note: missed loop optimization: niters analysis .*" } */
     g();
   
-  for(k = 15;k >= n;k--) /* { dg-warning "missed loop optimization.*overflow" } */
+  for(k = 15;k >= n;k--) /* { dg-message "note: missed loop optimization: niters analysis .*" } */
     g();
 }
diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c
index 5a7cab5..1421002 100644
--- a/gcc/tree-ssa-loop-niter.c
+++ b/gcc/tree-ssa-loop-niter.c
@@ -2378,9 +2378,9 @@  number_of_iterations_exit (struct loop *loop, edge exit,
     return true;
 
   if (warn)
-    warning_at (gimple_location_safe (stmt),
-		OPT_Wunsafe_loop_optimizations,
-		"missed loop optimization, the loop counter may overflow");
+    dump_printf_loc (MSG_MISSED_OPTIMIZATION, gimple_location_safe (stmt),
+		     "missed loop optimization: niters analysis ends up "
+		     "with assumptions.\n");
 
   return false;
 }