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Re: [PR debug/46240] don't introduce debug bind stmts at merge edges
On Jan 17, 2011, Richard Guenther <richard.guenther@gmail.com> wrote:
> Ok. I guess we are sure we never have an unused LHS and thus
> no PHI node for the result?
The unused result will have got a PHI node and a debug stmt at the
confluence point at first, but I suppose the PHI node may be optimized
away, but then I *think* we'd have removed the assignment from the call
as well. Anyhow, good catch, better not take the risk at this point.
> Thus, I'd be more happy when that asserts for phi_nodes would not be
> there (I think we can also have non-cleaned up degenerate PHIs).
Both asserts removed. Here's what I checked in.
for gcc/ChangeLog
from Alexandre Oliva <aoliva@redhat.com>
PR debug/46240
* tree-into-ssa.c (maybe_register_def): Do not attempt to add
debug bind stmt on merge edges.
for gcc/testsuite/ChangeLog
from Alexandre Oliva <aoliva@redhat.com>
PR debug/46240
* g++.dg/debug/pr46240.cc: New.
Index: gcc/tree-into-ssa.c
===================================================================
--- gcc/tree-into-ssa.c.orig 2011-01-16 10:29:55.920942500 -0200
+++ gcc/tree-into-ssa.c 2011-01-19 20:05:53.727149469 -0200
@@ -1869,11 +1869,27 @@ maybe_register_def (def_operand_p def_p,
gcc_assert (!ef);
ef = e;
}
- gcc_assert (ef
- && single_pred_p (ef->dest)
- && !phi_nodes (ef->dest)
- && ef->dest != EXIT_BLOCK_PTR);
- gsi_insert_on_edge_immediate (ef, note);
+ /* If there are other predecessors to ef->dest, then
+ there must be PHI nodes for the modified
+ variable, and therefore there will be debug bind
+ stmts after the PHI nodes. The debug bind notes
+ we'd insert would force the creation of a new
+ block (diverging codegen) and be redundant with
+ the post-PHI bind stmts, so don't add them.
+
+ As for the exit edge, there wouldn't be redundant
+ bind stmts, but there wouldn't be a PC to bind
+ them to either, so avoid diverging the CFG. */
+ if (ef && single_pred_p (ef->dest)
+ && ef->dest != EXIT_BLOCK_PTR)
+ {
+ /* If there were PHI nodes in the node, we'd
+ have to make sure the value we're binding
+ doesn't need rewriting. But there shouldn't
+ be PHI nodes in a single-predecessor block,
+ so we just add the note. */
+ gsi_insert_on_edge_immediate (ef, note);
+ }
}
else
gsi_insert_after (&gsi, note, GSI_SAME_STMT);
Index: gcc/testsuite/g++.dg/debug/pr46240.cc
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ gcc/testsuite/g++.dg/debug/pr46240.cc 2011-01-19 20:03:25.675777762 -0200
@@ -0,0 +1,172 @@
+// { dg-do compile }
+// { dg-options "-O3 -g" }
+
+template <typename T>
+T &max (T &a, T &b)
+{
+ if (a < b) return b; else return a;
+}
+int foo (double);
+struct S
+{
+ struct T
+ {
+ int dims, count;
+ T (int, int) : dims (), count () {}
+ };
+ T *rep;
+ S () {}
+ S (int r, int c) : rep (new T (r, c)) {}
+ ~S () { delete rep; }
+};
+template <typename T>
+struct U
+{
+ static T epsilon () throw ();
+};
+template <class T>
+struct V
+{
+ struct W
+ {
+ T * data;
+ int count;
+ W (int n) : data (new T[n]), count () {}
+ };
+ V::W *rep;
+ S dimensions;
+ int slice_len;
+ V (S s) : rep (new V <T>::W (get_size (s))) {}
+ int capacity () { return slice_len; }
+ int get_size (S);
+};
+template <class T>
+struct Z : public V <T>
+{
+ Z () : V <T> (S (0, 0)) {}
+ Z (int r, int c) : V <T> (S (r, c)) {}
+};
+template <class T>
+struct A : public Z <T>
+{
+ A () : Z <T> () {}
+ A (int n, int m) : Z <T> (n, m) {}
+};
+template <class T>
+struct B : public V <T>
+{
+};
+struct C : public A <double>
+{
+ C () : A <double> () {}
+ C (int r, int c) : A <double> (r, c) {}
+};
+struct D : public B <double>
+{
+};
+template <class T>
+struct E
+{
+};
+template <class T>
+struct G : public E <T>
+{
+};
+struct H : public G <double>
+{
+};
+template <class R>
+struct I
+{
+ R scl, sum;
+ void accum (R val)
+ {
+ R t = __builtin_fabs (val);
+ if (scl == t)
+ sum += 1;
+ }
+ operator R () { __builtin_sqrt (sum); return R (); }
+};
+template <class R>
+struct J
+{
+ template < class U > void accum (U val) {}
+ operator R () { return R (); }
+};
+template <class R>
+struct K
+{
+ R max;
+ template <class U> void accum (U val)
+ {
+ double z = __builtin_fabs (val);
+ max = ::max (max, z);
+ }
+ operator R () { return max; }
+};
+template <class R>
+struct L
+{
+ unsigned num;
+ template <class U> void accum (U) {}
+ operator R () { return num; }
+};
+template <class T, class R, class S>
+void bar (V <T> &v, R &res, S acc)
+{
+ for (int i = 0; i < v.capacity (); i++)
+ acc.accum ((i));
+ res = acc;
+}
+template <class T, class R>
+void bar (B <T> &v, R)
+{
+ R res;
+ bar (v, res, I <R> ());
+}
+template <class T, class R>
+R bar (A <T> &v, R p)
+{
+ R res;
+ if (p == 2)
+ bar (v, res, I <R> ());
+ else if (p == 1)
+ bar (v, res, J <R> ());
+ else if (p == sizeof (float) ? (p) : foo (p))
+ {
+ if (p > 0)
+ bar (v, res, K <R> ());
+ }
+ else if (p == 0)
+ bar (v, res, L <R> ());
+ return res;
+}
+template <class CT, class VectorT, class R>
+void
+baz (CT m, R p, R tol, int maxiter, VectorT)
+{
+ VectorT y (0, 0), z (0, 1);
+ R q = 0;
+ R gamma = 0, gamma1 = 0;
+ gamma = bar (y, p);
+ (void) (bar (z, q) <= (gamma1 <= gamma));
+}
+int a = 100;
+template <class CT, class VectorT, class R>
+void
+test (CT m, R p, VectorT)
+{
+ VectorT x;
+ R sqrteps (U <R>::epsilon ());
+ baz (m, p, sqrteps, a, x);
+}
+void
+fn (D x, double p)
+{
+ bar (x, p);
+}
+void
+fn (H x, double p)
+{
+ test (x, p, C ());
+}
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist Red Hat Brazil Compiler Engineer