http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49158
Summary: Incorrect pointer arithmetic with negative offset
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: critical
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: a...@os.inf.tu-dresden.de
Created attachment 24353
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24353
The source code triggering the bug
The compiler generates incorrect code for pointer arithmetic on an external
array of structures.
When you use 'array[-1] = x' the target addresses are correct when you use
'*(array -1) = x' the addresses are sizeof(void*) too low.
I tested the code for x86 and x86_64 both are affected
affected compiler version:
g++ (Debian 4.6.0-9) 4.6.1 20110524 (prerelease)
g++ 4.7.0, 4.6.0
works with: g++ 4.5.2
test.cc provides the source code, test.S generated with:
g++ -S -fverbose-asm -o test.S test.cc
shows the two inconsistent code snippets before and after the comment (#
comment from me).
