[PATCH] D12066: Introduce the ScopExpander as a SCEVExpander replacement

[Sanjoy Das via llvm-commits]

On Sun, Aug 16, 2015 at 2:24 PM, Sanjoy Das
<sanjoy at playingwithpointers.com> wrote:
> sanjoy added inline comments.
>
> ================
> Comment at: lib/Support/ScopHelper.cpp:292
> @@ +291,3 @@
> +
> +    Value *LHS = Expander.expandCodeFor(LHSScev, E->getType(), StartIP);
> +    Value *RHS = Expander.expandCodeFor(RHSScev, E->getType(), StartIP);
> ----------------
> I don't grok how Polly uses SCEVs, but won't `LHS` be identical to `Inst->getOperand(0)` here?  Likewise for `RHS` and `Inst->getOperand(1)`?  Why can't this function just `return E->getValue()` (after which `ScopExpander::expandCodeFor` should become equivalent to `SCEVExpander::expandCodeFor`)?

Sorry, I meant "Why can't this function just `return E;`"

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> http://reviews.llvm.org/D12066
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