> testcase shows that in 4.1/4.2/4.3/4.4 this is miscompiled only when using > -fno-ipa-reference, in 4.5 it is miscompiled always when optimizing > unless -fno-ipa-pure-const (as 4.5 added local-pure-const pass which is run > before ipa-reference) and in 4.6 this has been fixed by Honza when > doing ipa cleanups.
Maybe it would be better to simply change the kernel Makefiles to pass -fno-ipa-pure-const instead of adding volatiles everywhere. -Andi