On 19/09/18 10:16 +0100, Jonathan Wakely wrote:
On 17/09/18 23:15 +0200, Marc Glisse wrote:
On Mon, 17 Sep 2018, François Dumont wrote:
We talk about it a while back.
I've run testsuite several times since I have this patch on my
local copy. Note that when I implemented it the wrong way tests
started to fail so it is clearly having an effect on the generated
code.
* include/bits/c++config [__OPTIMIZE__](__glibcxx_assert): Define
as optimization hint
using __builtin_unreachable.
Ok to commit ?
I see for instance in bits/regex_automaton.tcc:
__glibcxx_assert(__m.count(__ref._M_next) > 0);
where __m is a map, which does not look so well suited for a
__builtin_unreachable. Is it using the wrong macro?
Yes, that looks like it's checking the implementation, but we should
only add assertions to check what users do (we just need to get our
own implementation right).
I'll test this patch.
diff --git a/libstdc++-v3/include/bits/regex_automaton.tcc b/libstdc++-v3/include/bits/regex_automaton.tcc
index 7a0e6a36a7a..5993fcfeeaf 100644
--- a/libstdc++-v3/include/bits/regex_automaton.tcc
+++ b/libstdc++-v3/include/bits/regex_automaton.tcc
@@ -220,16 +220,9 @@ namespace __detail
auto __v = __it.second;
auto& __ref = _M_nfa[__v];
if (__ref._M_next != _S_invalid_state_id)
- {
- __glibcxx_assert(__m.count(__ref._M_next) > 0);
- __ref._M_next = __m[__ref._M_next];
- }
- if (__ref._M_has_alt())
- if (__ref._M_alt != _S_invalid_state_id)
- {
- __glibcxx_assert(__m.count(__ref._M_alt) > 0);
- __ref._M_alt = __m[__ref._M_alt];
- }
+ __ref._M_next = __m.find(__ref._M_next)->second;
+ if (__ref._M_has_alt() && __ref._M_alt != _S_invalid_state_id)
+ __ref._M_alt = __m.find(__ref._M_alt)->second;
}
return _StateSeq(_M_nfa, __m[_M_start], __m[_M_end]);
}
