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| author | Alexandre Oliva <aoliva@redhat.com> | 2005-02-22 02:27:37 +0000 |
|---|---|---|
| committer | Alexandre Oliva <aoliva@gcc.gnu.org> | 2005-02-22 02:27:37 +0000 |
| commit | bb2e1640492f6b6989131cef45519dfd47a1acbb (patch) | |
| tree | e53536f3c19ce30de20e9fb83251734c20e5e305 | |
| parent | 1d27fed446abb6a831261c004803cf23d994b296 (diff) | |
| download | gcc-bb2e1640492f6b6989131cef45519dfd47a1acbb.zip gcc-bb2e1640492f6b6989131cef45519dfd47a1acbb.tar.gz gcc-bb2e1640492f6b6989131cef45519dfd47a1acbb.tar.bz2 | |
re PR tree-optimization/19786 (Aliasing optimisation bug)
gcc/ChangeLog:
PR tree-optimization/19786
* tree-ssa-alias.c (compute_flow_insensitive_aliasing): Add one
tag to another's may-alias bitmap when adding to the other's list.
gcc/testsuite/ChangeLog:
PR tree-optimization/19786
* g++.dg/tree-ssa/pr19786.C: New.
From-SVN: r95377
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gcc/testsuite/g++.dg/tree-ssa/pr19786.C | 48 | ||||
| -rw-r--r-- | gcc/tree-ssa-alias.c | 1 |
4 files changed, 60 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 16cb58b..fa37096 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-02-21 Alexandre Oliva <aoliva@redhat.com> + + PR tree-optimization/19786 + * tree-ssa-alias.c (compute_flow_insensitive_aliasing): Add one + tag to another's may-alias bitmap when adding to the other's list. + 2005-02-21 DJ Delorie <dj@redhat.com> * tree-ssa-loop-ivopts.c (computation_cost): Start register diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 0eae765..dd742ed 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2005-02-21 Alexandre Oliva <aoliva@redhat.com> + + PR tree-optimization/19786 + * g++.dg/tree-ssa/pr19786.C: New. + 2005-02-21 Tobias Schl"uter <tobias.schlueter@physik.uni-muenchen.de> * lib/gfortran-dg.exp (gfortran-dg-test): Split long regexps. diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr19786.C b/gcc/testsuite/g++.dg/tree-ssa/pr19786.C new file mode 100644 index 0000000..faaecdf --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/pr19786.C @@ -0,0 +1,48 @@ +// { dg-do run } +/* { dg-options "-O2" } */ + +// We used to get alias grouping wrong on this one, hoisting accesses +// to the vector's end out of the loop. + +#include <vector> +#include <cassert> + +struct A +{ + double unused; // If I remove it => it works. + std::vector<int> v; + + A() : v(1) {} +}; + +inline // If not inline => it works. +A g() +{ + A r; + r.v.resize(2); + r.v[0] = 1; + + while (!r.v.empty() && r.v.back() == 0) + r.v.pop_back(); + + return r; +} + +A f(const A &a) +{ + if (a.v.empty()) return a; + if (a.v.empty()) return a; + + // A z = g(); return z; // If I return like this => it works. + return g(); +} + +int main() +{ + A a; + A b; + A r = f(a); + assert(r.v.size() != 0); + + return 0; +} diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c index 3e5f8e3..bfa1685 100644 --- a/gcc/tree-ssa-alias.c +++ b/gcc/tree-ssa-alias.c @@ -1116,6 +1116,7 @@ compute_flow_insensitive_aliasing (struct alias_info *ai) /* Since TAG2 does not have any aliases of its own, add TAG2 itself to the alias set of TAG1. */ add_may_alias (tag1, tag2); + SET_BIT (may_aliases1, var_ann (tag2)->uid); } } } |