http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55554
Bug #: 55554
Summary: GCC generates illegal instruction for optimization
level >=O1 when invoking casted pointer to function
Classification: Unclassified
Product: gcc
Version: 4.2.1
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: avshaba...@gmail.com
Created attachment 28843
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=28843
smallest possible program that reproduces an error
The attached program generates an illegal instruction error when compiled on
Mac OS X 10.8.2.
== GCC info ==
$ gcc -v
Using built-in specs.
Target: i686-apple-darwin11
Configured with: /private/var/tmp/llvmgcc42/llvmgcc42-2336.11~67/src/configure
--disable-checking --enable-werror
--prefix=/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2
--mandir=/share/man --enable-languages=c,objc,c++,obj-c++
--program-prefix=llvm- --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/
--with-slibdir=/usr/lib --build=i686-apple-darwin11
--enable-llvm=/private/var/tmp/llvmgcc42/llvmgcc42-2336.11~67/dst-llvmCore/Developer/usr/local
--program-prefix=i686-apple-darwin11- --host=x86_64-apple-darwin11
--target=i686-apple-darwin11 --with-gxx-include-dir=/usr/include/c++/4.2.1
Thread model: posix
gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00)
== BUG ==
To reproduce the bug compile with O1 and higher:
$ gcc -std=c99 -fomit-frame-pointer -O1 gccbug.c -o gccbug
$ ./gccbug
Illegal instruction: 4
== WORKAROUND ==
Compile with O0:
$ gcc -std=c99 -fomit-frame-pointer -O0 -g gccbug.c -o gccbug
$ ./gccbug
OK
OK
OK
OK
Please, feel free to contact me if you happen to know *any* (GCC-specific)
workaround for the specified issue.
