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