On Tuesday, 7 December 2021 08:43:56 CET Richard Biener wrote:
> On Mon, Dec 6, 2021 at 11:47 AM Matthias Kretz <m.kr...@gsi.de> wrote:
> > While reading the hash_map code I noticed this inconsistency. Bootstrapped
> > and regtested on x86_64. OK for trunk?
>
> I've inspected two users of said overload and they return true. Did you
> look at the rest? I assume that bootstrapping and testing with asserting
> that the callback never returns false in that overload should succeed?
> That said, the inconsistency is bad - but how can we be sure we're not
> relying on that? I mean more than just bootstrapping and regtesting ;)
I've checked all users now; and added more documentation. OK for trunk now?
---- 8< ----
The hash_map::traverse overload taking a non-const Value pointer breaks
if the callback returns false. The other overload should behave the
same.
Signed-off-by: Matthias Kretz <m.kr...@gsi.de>
gcc/ChangeLog:
* hash-map.h (hash_map::traverse): Let both overloads behave the
same.
* predict.c (assert_is_empty): Return true, thus not changing
behavior.
---
gcc/hash-map.h | 6 ++++--
gcc/predict.c | 2 +-
2 files changed, 5 insertions(+), 3 deletions(-)
--
──────────────────────────────────────────────────────────────────────────
Dr. Matthias Kretz https://mattkretz.github.io
GSI Helmholtz Centre for Heavy Ion Research https://gsi.de
stdₓ::simd
──────────────────────────────────────────────────────────────────────────
diff --git a/gcc/hash-map.h b/gcc/hash-map.h
index dd039f10343..c4fe26cf5d1 100644
--- a/gcc/hash-map.h
+++ b/gcc/hash-map.h
@@ -217,7 +217,8 @@ public:
}
/* Call the call back on each pair of key and value with the passed in
- arg. */
+ arg until either the call back returns false or all pairs have been seen.
+ The traversal is unordered. */
template<typename Arg, bool (*f)(const typename Traits::key_type &,
const Value &, Arg)>
@@ -225,7 +226,8 @@ public:
{
for (typename hash_table<hash_entry>::iterator iter = m_table.begin ();
iter != m_table.end (); ++iter)
- f ((*iter).m_key, (*iter).m_value, a);
+ if (!f ((*iter).m_key, (*iter).m_value, a))
+ break;
}
template<typename Arg, bool (*f)(const typename Traits::key_type &,
diff --git a/gcc/predict.c b/gcc/predict.c
index 3cb4e3c0eb5..1a1da7e8360 100644
--- a/gcc/predict.c
+++ b/gcc/predict.c
@@ -3044,7 +3044,7 @@ assert_is_empty (const_basic_block const &, edge_prediction *const &value,
void *)
{
gcc_assert (!value);
- return false;
+ return true;
}
/* Predict branch probabilities and estimate profile for basic block BB.
