On 08/16/2018 09:43 AM, Vicent Brocal Tortosa wrote:
> Hello,
>
> We are forced to use version 4.4.2 of GCC C compiler for a certain project
> and to analyze the potential impact, to our software, of bugs detected for
> this GCC version.
>
> I am already aware that bugs reported for 4.4.x versions may also be present
> in 4.4.2, but for the moment we have decided to keep the scope of the
> analysis for the ones reported specifically for this version ("know to fail").
>
> In the GCC bugzilla tracker I have found a couple of them that bother me (we
> intend to use -O2 optimizations):
>
> Bug 42614 - [4.4 Regression] FRE optimizes away valid code after IPA inlining.
> Bug 42691 - [4.4/4.5 regression] problematic REG_EQUAL note added to SUBREG.
>
> Can someone recommend a general workaround for them (e.g. deactivating the
> affected optimizations) or any other approach that can be used to ensure that
> there is no impact to the object code?
I doubt there's an acceptable general workaround. THe first would
probably require disabling FRE or IPA which is a pretty big hammer.
THe second you might be able to disable RTL forward propagation.
You're likely better off upgrading or applying the referenced fixes to
your compiler.
gcc-4.4 is horribly old at this point. You're unlikely to get many
resources to help you if things go wrong.
jeff
