search for: scevsimplifier

...here), but I personally am in >>> the "make the cleanup passes smarter" camp. We can also try to make >>> SCEV expansion smarter -- not by putting more things in SCEVExpander >>> (it is already complex enough!), but by splitting out a dedicated >>> SCEVSimplifier that you invoke on code generated from SCEVExpander to >>> strength reduce it. SCEVSimplifier can then internally use routines >>> in SCEV, so that it is "as smart as" SCEV in most cases. >>> >>> — Sanjoy > > Combine the efforts of making t...

...ybe Chris, Andy or Dan can chime in here), but I personally am in > the "make the cleanup passes smarter" camp. We can also try to make > SCEV expansion smarter -- not by putting more things in SCEVExpander > (it is already complex enough!), but by splitting out a dedicated > SCEVSimplifier that you invoke on code generated from SCEVExpander to > strength reduce it. SCEVSimplifier can then internally use routines > in SCEV, so that it is "as smart as" SCEV in most cases. > > — Sanjoy SCEV is super useful as an analysis without SCEVExpander. The only real issue...

SCEV expansion sometimes generates redundent expr even if there is an available expr which can be reused. The redundent exprs can be a lot different from existing exprs so that existing cleanup passes cannot remove them. https://llvm.org/bugs/show_bug.cgi?id=24920 https://llvm.org/bugs/show_bug.cgi?id=24442 https://reviews.llvm.org/D12090 and https://reviews.llvm.org/D21313 already relieved the