RHBA-2011:1644 - Bug Fix Advisory

Topic

Updated gcc packages that fix various bugs and add three enhancements are now
available for Red Hat Enterprise Linux 6.

Description

The gcc packages include C, C++, Java, Fortran, Objective C, Objective C++, and
Ada 95 GNU compilers, along with related support libraries.

This update fixes the following bugs:

• The previous version of GCC incorrectly assumed that processors based on the

AMD's multi-core architecture code named Bulldozer support the 3DNow!
instruction set. This update adapts the underlying source code to make sure that
GCC no longer uses the 3DNow! instructions on these processors. (BZ#696352)

• On the PowerPC architecture, GCC previously passed the V2DImode vector

parameters using the stack and returned them in integer registers, which does
not comply with the Application Binary Interface (ABI). This update corrects
this error so that GCC now passes these parameters using the AltiVec parameter
registers and returns them via the AltiVec return value register. (BZ#705764)

• Previously, GCC did not flush all pending register saves in a Frame

Description Entry (FDE) before inline assembly instructions. This may have led
to various problems when the inline assembly code modified those registers. With
this update, GCC has been adapted to flush pending register saves in FDE before
inline assembly instructions, resolving this issue. (BZ#721376)

• Prior to this update, the gcov test coverage utility sometimes incorrectly

counted even opening brackets, which caused it to produce inaccurate statistics.
This update applies a patch that corrects this error so that gcov ignores such
brackets, as expected. (BZ#732802)

• When processing source code that extensively used overloading (that is, with

hundreds or more overloads of the same function or method), the previous version
of the C++ front end consumed a large amount of memory. This negatively affected
the overall compile time and the amount of used system resources. With this
update, the C++ front end has been optimized to use less resources in this
scenario. (BZ#732807)

As well, this update adds the following enhancements:

• This update adds support for new "-mfsgsbase", "-mf16c", and "-mrdrnd" command

line options, as well as corresponding intrinsics to the immintrin.h header
file. This allows for reading FS and GS base registers, retrieving random data
from the random data generator, and converting between floating point and
half-precision floating-point types. (BZ#696145)

• GCC now supports AMD's next generation processors. These processors can now be

specified on the command line via the "-march=" and "-mtune=" command line
options. (BZ#696370)

• GCC now supports Intel's next generation processor instrinsics and

instructions for reading the hardware random number generator. (BZ#696495)

All users of gcc are advised to upgrade to these updated packages, which fix
these bugs and add these enhancements.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 732807 - Heavy use of overloading causes g++ memory usage to skyrocket

CVEs

(none)

References

(none)