Linaro GCC 4.5 and 4.6 2011-04 released

[Michael Hope]

The Linaro Toolchain Working Group is pleased to announce the release
of both Linaro GCC 4.5 and Linaro GCC 4.6.

Linaro GCC 4.5 2011.04 is the ninth release in the 4.5 series.  Based
off the latest
GCC 4.5.2+svn171921, it adds new optimisations, support for Android,
and fixes for many of the issues found in the last month.

Linaro GCC 4.6 2011.04 is the second release in the 4.6 series. Based off the
latest GCC 4.6.0+svn171921, it is the first supported release of the
new series and includes a significant number of mainstreamed patches
from 4.5.

Interesting changes in 4.6 include:
 * Updates to 4.6.0+r171921
 * Adds conditional store sinking to the vectoriser
 * Brings in a significant number of the Linaro GCC 4.5 patches that
   are in mainline

Interesting changes in 4.5 include:
 * Updates to 4.5.2+r172013
 * Disables the shrink wrap optimisation by default
 * Adds support for swing-modulo scheduling (SMS) on ARM
 * Adds support for Android and the Bionic C library
 * Optimises -fvar-tracking, greatly reducing memory used when
   compiling large files (seen in QEMU)

Fixes:
 * 'volatile' being ignored on volatile struct members
 * A potential register clobber in arm_negdi2
 * An error in libgcc that prevented it being built with -Os
 * Multiple shrink wrap bugs (LP: #731665, 721023, 736081, 758082,
   730860, 736439, 721023)
 * LP: #730440 incorrect immediate for movt (seen in Firebird)
 * LP: #728315 extension elimination pass mishandles subregs of
   promoted variables (seen on MIPS)
 * LP: #675347 volatile int causes inline assembly build failure (seen
   in Qt)

SMS is an optimisation that works on innermost loops and reorders the
instructions by overlapping different locations.  An example is that
the values for the next loop may be loaded during the current loop,
making the values already ready when the next loop starts.

SMS is disabled by default.  To try it, add the options '-fmodulo-sched
-fmodulo-sched-allow-regmoves'.

The source tarball is available from:
 https://launchpad.net/gcc-linaro/+milestone/4.5-2011.04-0
 https://launchpad.net/gcc-linaro/+milestone/4.6-2011.04-0

Downloads are available from the Linaro GCC page on Launchpad:
 https://launchpad.net/gcc-linaro

-- Michael