Compile the attached program with:
gcc -O0 wrong-code-tree-vrp.cc
gcc -O2 wrong-code-tree-vrp.cc
gcc -O2 -fno-tree-vrp wrong-code-tree-vrp.cc
with gcc 4.1.0, native i686-pc-linux-gnu.
The -O0 and -O2 -fno-tree-vrp versions produce the correct output: g1[3] ==
100, g1[4] == 100. The -O2 version produces incorrect output: g1[3] == 101,
g1[4] == 101.
Works fine with gcc 4.0.3, native i686-pc-linux-gnu, -O2.
Still broken with gcc 4.2-20060513, native i686-pc-linux-gnu, -O2.
Haven't checked with gcc 4.1-LATEST yet.
--
Summary: wrong code, apparently due to bad VRP
Product: gcc
Version: 4.1.0
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: mec at google dot com
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27603
