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?
Thanks,
bin
2017-07-13 Bin Cheng <bin.ch...@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.ch...@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 --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..354d362
--- /dev/null
+++ b/gcc/testsuite/g++.dg/tree-ssa/pr81408.C
@@ -0,0 +1,93 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -std=gnu++11 -fdump-tree-ivopts-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)
+ a::ax << c.ay << a::av;
+}
+
+/* { dg-final { scan-tree-dump "note: missed loop optimization: niters
analysis ends up with assumptions." "ivopts" } } */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c
b/gcc/testsuite/gcc.dg/tree-ssa/pr19210-1.c
index 3c8ee06..3c18470 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 -fdump-tree-ivopts-details -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++) /* missed optimization for this loop. */
g();
- for(k = 0;k <= n;k += 4) /* { dg-warning "missed loop
optimization.*overflow" } */
+ for(k = 0;k <= n;k += 4) /* missed optimization for this loop. */
g();
/* We used to get warning for this loop. However, since then # of iterations
@@ -21,9 +21,14 @@ 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) /* missed optimization for this loop. */
g();
- for(k = 15;k >= n;k--) /* { dg-warning "missed loop optimization.*overflow"
} */
+ for(k = 15;k >= n;k--) /* missed optimization for this loop. */
g();
}
+
+/* { dg-final { scan-tree-dump "pr19210-1.c:9:.*: missed loop optimization:
niters analysis ends up with assumptions." "ivopts" } } */
+/* { dg-final { scan-tree-dump "pr19210-1.c:12:.*: missed loop optimization:
niters analysis ends up with assumptions." "ivopts" } } */
+/* { dg-final { scan-tree-dump "pr19210-1.c:24:.*: missed loop optimization:
niters analysis ends up with assumptions." "ivopts" } } */
+/* { dg-final { scan-tree-dump "pr19210-1.c:27:.*: missed loop optimization:
niters analysis ends up with assumptions." "ivopts" } } */
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;
}
