[llvm-branch-commits] [llvm] [LSR] Preserve LCSSA in SCEVRewriter (PR #191665)

[Aiden Grossman via llvm-branch-commits]

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@@ -6165,7 +6165,7 @@ LSRInstance::LSRInstance(Loop *L, IVUsers &IU, ScalarEvolution &SE,
       MSSAU(MSSAU), AMK(PreferredAddresingMode.getNumOccurrences() > 0
                             ? PreferredAddresingMode
                             : TTI.getPreferredAddressingMode(L, &SE)),
-      Rewriter(SE, "lsr", false), BaselineCost(L, SE, TTI, AMK) {
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boomanaiden154 wrote:

With the NewPM, loops are guaranteed to be in LCSSA before the start of a loop pass, so it should just always be true.

With the legacy PM, this is not guaranteed by default, although I want to force it to be true by default to better match the NewPM soonish, but need to track down some regressions first.

https://github.com/llvm/llvm-project/pull/191665