On Fri, 19 Aug 2016, Kugan Vivekanandarajah wrote: > On 19 August 2016 at 12:09, Kugan Vivekanandarajah > <kugan.vivekanandara...@linaro.org> wrote: > > The testcase pr33738.C for warning fails with early-vrp patch. The > > reason is, with early-vrp ccp2 is folding the comparison that used to > > be folded in simplify_stmt_for_jump_threading. Since early-vrp does > > not perform jump-threading is not optimized there. > > > > Attached patch adds this warning to tree-ssa-ccp.c. We might also run > > into some other similar issues in the future. > > Sorry, I attached the wrong patch (with typo). Here is the correct one.
I think emitting this warning from GIMPLE optimizations is fundamentally flawed and the warning should be removed there and put next to the cases we alrady handle in c/c-common.c:shorten_compare (or in FE specific code). I see no reason why only VRP or CCP would do the simplification for -fstrict-enums enums (thus it seems to be missing from the generic comparison folders). Richard. > Thanks, > Kugan > > > > > Bootstrapped and regression tested on x86_64-linux-gnu with no new > > regressions. > > > > Is this OK for trunk? > > > > Thanks, > > Kugan > > > > gcc/ChangeLog: > > > > 2016-08-18 Kugan Vivekanandarajah <kug...@linaro.org> > > > > * tree-ssa-ccp.c (ccp_fold_stmt): If the comparison is being folded > > and the operand on the LHS is being compared against a constant > > value that is outside of type limit, issue warning. > k
